Digi XBee Cellular 3G Global Embedded Modem User Guide Users 90001541

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Digi XBee® Cellular 3G Global
Embedded Modem

User Guide

Revision history—90001541
Revision Date

Description

January
2018

Added the TS, N1 and N2 commands and information on socket limits. Added
support for RSSI PWM, SPI and I2C. Indicated the number of supported
sockets.

February Noted UDP 1024 byte payload limit. Added European certifications. Added
2018
instructions for sending an SCI request to Remote Manager.

March
2018

Added Australian and New Zealand certifications.

June
2018

0B software release. Added file system and TLS sections, AT commands and
related changes.

August
2018

Updated list of cipher suites. Updated Get Started section.

Trademarks and copyright
Digi, Digi International, and the Digi logo are trademarks or registered trademarks in the United
States and other countries worldwide. All other trademarks mentioned in this document are the
property of their respective owners.
© 2018 Digi International Inc. All rights reserved.

Disclaimers
Information in this document is subject to change without notice and does not represent a
commitment on the part of Digi International. Digi provides this document “as is,” without warranty of
any kind, expressed or implied, including, but not limited to, the implied warranties of fitness or
merchantability for a particular purpose. Digi may make improvements and/or changes in this manual
or in the product(s) and/or the program(s) described in this manual at any time.

Warranty
To view product warranty information, go to the following website:
www.digi.com/howtobuy/terms

Send comments
Documentation feedback: To provide feedback on this document, send your comments to
techcomm@digi.com.

Customer support
Digi Technical Support: Digi offers multiple technical support plans and service packages to help our
customers get the most out of their Digi product. For information on Technical Support plans and

Digi XBee Cellular 3G Global Embedded Modem User Guide

pricing, contact us at +1 952.912.3444 or visit us at www.digi.com/support.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Contents
Digi XBee Cellular 3G Global Embedded Modem User Guide
Applicable firmware and hardware
SIM cards

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Get started with the XBee Cellular Modem Development Kit
Identify the kit contents
Connect the hardware
XBIB-U-DEV reference
Cellular service
Configure the device using XCTU
Add a device
Check for cellular registration and connection
Update to the latest firmware

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Connection examples
Connect to the Echo server
Debugging
Connect to the ELIZA server
Debugging
Connect to the Daytime server
Debugging
Perform a (GET) HTTP request
Debugging
Get started with CoAP
CoAP terms
CoAP quick start example
Configure the device
Example: manually perform a CoAP request
Example: use Python to generate a CoAP message
Connect to a TCP/IP address
Debugging
Get started with MQTT
Example: MQTT connect
Send a connect packet
Example: send messages (publish) with MQTT
Example: receive messages (subscribe) with MQTT
Use MQTT over the XBee Cellular Modem with a PC
Software libraries

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Get started with MicroPython
About MicroPython
Why use MicroPython
MicroPython on the XBee Cellular Modem
Use XCTU to enter the MicroPython environment
Use the MicroPython Terminal in XCTU
Troubleshooting
Example: hello world
Example: turn on an LED
Exit MicroPython mode
Other terminal programs
Tera Term for Windows
Use picocom in Linux

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Technical specifications
Interface and hardware specifications
RF characteristics
Networking specifications
Power requirements
Power consumption
Electrical specifications
Regulatory approvals

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Hardware
Mechanical drawings
Pin signals
Pin connection recommendations
RSSI PWM
SIM card
The Associate LED

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Antenna recommendations
Antenna placement

Design recommendations
Power supply considerations
Add a capacitor to the RESET line
Heat considerations
Add a fan to provide active cooling

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Cellular connection process
Connecting
Cellular network
Data network connection
Data communication with remote servers (TCP/UDP)
Disconnecting

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SMS encoding

Modes
Select an operating mode
Transparent operating mode
API operating mode
Bypass operating mode
Enter Bypass operating mode
Leave Bypass operating mode
Restore cellular settings to default in Bypass operating mode
Command mode
Enter Command mode
Troubleshooting
Send AT commands
Response to AT commands
Apply command changes
Make command changes permanent
Exit Command mode
MicroPython mode

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Sleep modes
About sleep modes
Normal mode
Pin sleep mode
Cyclic sleep mode
Cyclic sleep with pin wake up mode
Airplane mode
The sleep timer
MicroPython sleep behavior

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Serial communication
Serial interface
Serial data
UART data flow
Serial buffers
CTS flow control
RTS flow control

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SPI operation
SPI communications
Full duplex operation
Low power operation
Select the SPI port
Force UART operation
Data format

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File system
Overview of the file system
Directory structure
Paths
Secure files
XCTU interface
Encrypt files

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Socket behavior
Supported sockets
Socket timeouts
Socket limits in API mode
Enable incoming TCP sockets in API mode
API mode behavior for outgoing TCP and SSL connections
API mode behavior for outgoing UDP data
API mode behavior for incoming TCP connections
API mode behavior for incoming UDP data
Transparent mode behavior for outgoing TCP and SSL connections
Transparent mode behavior for outgoing UDP data
Transparent mode behavior for incoming TCP connections
Transparent mode behavior for incoming UDP connections

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Transport Layer Security (TLS)
TLS AT commands
Transparent mode and TLS
API mode and TLS
Key formats
Certificate formats
Certificate limitations
Cipher suites
Server Name Indication (SNI)

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AT commands
Special commands
AC (Apply Changes)
FR (Force Reset)
RE (Restore Defaults)
WR (Write)
Cellular commands
PH (Phone Number)
S# (ICCID)
IM (IMEI)
MN (Operator)
MV (Modem Firmware Version)
DB (Cellular Signal Strength)
AN (Access Point Name)
CP (Carrier Profile)
AM (Airplane Mode)
Network commands

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Digi XBee Cellular 3G Global Embedded Modem User Guide

IP (IP Protocol)
TL (SSL/TLS Protocol Version)
$0 (SSL/TLS Profile 0)
$1 (SSL/TLS Profile 1)
$2 (SSL/TLS Profile 2)
TM (IP Client Connection Timeout)
TS (IP Server Connection Timeout)
DO (Device Options)
EQ (Remote Manager FQDN)
Addressing commands
SH (Serial Number High)
SL (Serial Number Low)
MY (Module IP Address)
P# (Destination Phone Number)
N1 (DNS Address)
N2 (DNS Address)
DL (Destination Address)
OD (Operating Destination Address)
DE (Destination Port)
C0 (Source Port)
LA (Lookup IP Address of FQDN)
Serial interfacing commands
BD (Baud Rate)
NB (Parity)
SB (Stop Bits)
RO (Packetization Timeout)
TD (Text Delimiter)
FT (Flow Control Threshold)
AP (API Enable)
I/O settings commands
D0 (DIO0/AD0)
D1 (DIO1/AD1)
D2 (DIO2/AD2)
D3 (DIO3/AD3)
D4 (DIO4)
D5 (DIO5/ASSOCIATED_INDICATOR)
D6 (DIO6/RTS)
D7 (DIO7/CTS)
D8 (DIO8/SLEEP_REQUEST)
D9 (DIO9/ON_SLEEP)
P0 (DIO10/PWM0 Configuration)
P1 (DIO11/PWM1 Configuration)
P2 (DIO12 Configuration)
PD (Pull Direction)
PR (Pull-up/down Resistor Enable)
M0 (PWM0 Duty Cycle)
I/O sampling commands
TP (Temperature)
IS (Force Sample)
Sleep commands
SM (Sleep Mode)
SP (Sleep Period)
ST (Wake Time)
Command mode options
CC (Command Sequence Character)

Digi XBee Cellular 3G Global Embedded Modem User Guide

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CT (Command Mode Timeout)
CN (Exit Command mode)
GT (Guard Times)
MicroPython commands
PS (Python Startup)
PY (MicroPython Command)
Firmware version/information commands
VR (Firmware Version)
VL (Verbose Firmware Version)
HV (Hardware Version)
AI (Association Indication)
HS (Hardware Series)
CK (Configuration CRC)
Diagnostic interface commands
DI (Remote Manager Indicator)
CI (Protocol/Connection Indication)
Execution commands
NR (Network Reset)
!R (Modem Reset)
File system commands
Error responses
ATFS (File System)
ATFS PWD
ATFS CD directory
ATFS MD directory
ATFS LS [directory]
ATFS PUT filename
ATFS XPUT filename
ATFS HASH filename
ATFS GET filename
ATFS MV source_path dest_path
ATFS RM file_or_directory
ATFS INFO
ATFS FORMAT confirm

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Operate in API mode
API mode overview
Use the AP command to set the operation mode
API frame format
API operation (AP parameter = 1)
API operation with escaped characters (AP parameter = 2)

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API frames
AT Command - 0x08
Transmit (TX) SMS - 0x1F
Transmit (TX) Request: IPv4 - 0x20
Tx Request with TLS Profile - 0x23
AT Command Response - 0x88
Transmit (TX) Status - 0x89
Modem Status - 0x8A
Receive (RX) Packet: SMS - 0x9F
Receive (RX) Packet: IPv4 - 0xB0

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Digi XBee Cellular 3G Global Embedded Modem User Guide

Configure the XBee Cellular Modem using Digi Remote Manager
Create a Remote Manager account
Get the XBee Cellular Modem IMEI number
Add a XBee Cellular Modem to Remote Manager
Update the firmware
Update the firmware using web services
Example: update the XBee firmware synchronously with Python 3.0
Example: use the device's firmware image to update the XBee firmware synchronously

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Troubleshooting
Cannot find the serial port for the device
Condition
Solution
Other possible issues
Enable Virtual COM port (VCP) on the driver
Correct a macOS Java error
Condition
Solution
Unresponsive cellular component in Bypass mode
Condition
Solution
Not on expected network after APN change
Condition
Solution
Syntax error at line 1
Solution
Error Failed to send SMS
Solution

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Regulatory information
Modification statement
Interference statement
Antennas
FCC (USA) exposure notice
ISED (Canada) exposure notice
FCC Class B digital device notice
Labeling requirements for the host device
Europe (CE)
Maximum power and frequency specifications
OEM labeling requirements
Declarations of conformity
ACMA (Australia)
RSM (New Zealand)

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Digi XBee Cellular 3G Global Embedded Modem User
Guide
The XBee Cellular Modem contains a u-blox R410M-02B module that also supports NB-IoT. Digi has not
released support for the NB-IoT feature. Contact your sales representative if you would like more
information about our roadmap to support NB-IoT.
The XBee Cellular Modem integrates an embedded Wideband Code Division Multiple Access (WCDMA)
cellular module and enables original equipment manufacturers (OEMs) to incorporate 3G cellular
technology into their devices and applications without painful, time-consuming, and expensive FCC
and carrier end-device certifications.
With the full suite of standard XBee API frames and AT commands, existing XBee customers can
seamlessly transition to this new device with only minor software adjustments. When OEMs add the
XBee Cellular Modem to their product, they create a future-proof design with flexibility to switch
between wireless protocols or frequencies as needed.
You can read some frequently asked questions here.

Applicable firmware and hardware
This manual supports the following firmware:
n 113xx
It supports the following hardware:
n XBC-M5-UT-xxx

SIM cards
The XBee Cellular Modem requires a 4FF (Nano) size SIM card. The SIM interface supports both 1.8 V
and 3 V SIM types.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with the XBee Cellular Modem
Development Kit
This section describes how to connect the hardware in the XBee Cellular Modem Development Kit, and
provides some examples you can use to communicate with the device.
1. Identify the kit contents
2. Connect the hardware
3. Review the development board
4. Set up cellular service
5. Configure the device using XCTU
6. Use one of the following methods to verify your cellular connection:
n

Connect to the Echo server

Connect to the ELIZA server

Connect to the Daytime server

7. Review additional connection examples to help you learn how to use the device. See
Connection examples.
8. Review introductory MicroPython examples. See Get started with MicroPython.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Identify the kit contents
The Developer's kit includes the following:

One XBIB-U-DEV board

One 12 V power supply

One cellular antenna with U.FL connector

One USB cable

One XBee Cellular Modem
Note The XBee Cellular Modem comes
attached to the board in ESD wrap.
One SIM card

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with the XBee Cellular Modem Development Kit

Connect the hardware

1. The XBee Cellular Modem should already be plugged into the XBIB-U-DEV board.
2. The SIM card should be already be inserted into the XBee Cellular Modem. If not, install the
SIM card into the XBee Cellular Modem.
WARNING! Never insert or remove the SIM card while the device is powered!

WARNING! The development board power supply only supports 3G mode. It does not
support 2G mode.

3. Connect the antenna to the XBee Cellular Modem by aligning the U.FL connector carefully, then
firmly pressing straight down to seat the connector. You should hear a snap when the antenna
attaches correctly. U.FL is fragile and is not designed for multiple insertions, so exercise
caution when connecting or removing the antennas. We recommend using a U.FL removal tool.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with the XBee Cellular Modem Development Kit

Connect the hardware

4. Plug the 12 V power supply to the power jack on the development board.
5. Connect the USB cable from a PC to the USB port on the development board. The computer
searches for a driver, which can take a few minutes to install.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with the XBee Cellular Modem Development Kit

XBIB-U-DEV reference

XBIB-U-DEV reference
This picture shows the XBee USB development board and the table that follows explains the callouts
in the picture.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with the XBee Cellular Modem Development Kit

Number Item

Cellular service

Description

Programming header Header used to program XBee programmable devices.

Self power module

Advanced users only—voids the warranty. Depopulate R31 to
power the device using V+ and GND from J2 and J5. You can
connect sense lines to S+ and S- for sensing power supplies.
CAUTION: Voltage is not regulated. Applying the incorrect
voltage can cause fire and serious injury.1

Current testing

Depopulating R31 allows a current probe to be inserted across P6
terminals. The current though P6/R31 powers the device only.
Other supporting circuitry is powered by a different trace.

Loopback jumper

Populating P8 with a loopback jumper causes serial transmissions
both from the device and from the USB to loopback.

DC barrel plug: 6-20 V Greater than 500 mA loads require a DC supply for correct
operation. Plug in the external power supply prior to the USB
connector to ensure that proper USB communications are not
interrupted.

LED indicator

USB

RSSI indicator

See RSSI PWM. On the XBIB-U, more lights are better.

User buttons

Connected to DIO lines for user implementation.

Reset button

SPI power

Connect to the power board from 3.3 V.

SPI

Only used for surface-mount devices.

Indicator LEDs

DS5: ON/SLEEP
DS2: DIO12, the LED illuminates when driven low.
DS3: DIO11, the LED illuminates when driven low.
DS4: DIO4, the LED illuminates when driven low.

Through-hole XBee
sockets

20-pin header

Yellow: Modem sending serial/UART data to host.
Green: Modem receiving serial/UART data from host.
Red: Associate.

Maps to standard through-hole XBee pins.

Cellular service
Digi now offers Cellular Bundled Service plans. This service includes preconfigured cellular data
options that are ideal for IoT applications, bundled together with Digi Remote Manager for customers

1Powering the board with J2 and J5 without R31 removed can cause shorts if the USB or barrel plug power are

connected. Applying too high a voltage destroys electronic circuitry in the device and other board components
and/or can cause injury.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with the XBee Cellular Modem Development Kit

Configure the device using XCTU

who want to remotely monitor and manage their devices. To learn more, or obtain the plan that is
right for your needs, contact us:
n By phone: 1-877-890-4014 (USA/toll free) or +1-952-912-3456 (International). Select the
Wireless Plan Support or Activation option in the menu.
n

By email: Data.Plan.QuoteDesk@digi.com.

The XBee Cellular kit includes six months of free cellular service.1

Configure the device using XCTU
XBee Configuration and Test Utility (XCTU) is a multi-platform program that enables users to interact
with Digi radio frequency (RF) devices through a graphical interface. The application includes built-in
tools that make it easy to set up, configure, and test Digi RF devices.
XCTU does not work directly over an SPI interface.
For instructions on downloading and using XCTU, see the XCTU User Guide.
To use XCTU, you may need to install FTDI Virtual COM port (VCP) drivers onto your computer. Click
here to download the drivers for your operating system.
Note If you are on a macOS computer and encounter problems installing XCTU, see Correct a macOS
Java error.

Add a device
These instructions show you how to add the XBee Cellular Modem to XCTU.
If XCTU does not find your serial port, see Cannot find the serial port for the device and Enable Virtual
COM port (VCP) on the driver.
.
1. Launch XCTU
Note XCTU's Update the radio module firmware dialog box may open and will not allow you to
continue until you click Update or Cancel on the dialog.
2. Click Help > Check for XCTU Updates to ensure you are using the latest version of XCTU.
3. Click the Discover radio modules button

4. In the Discover radio devices dialog, select the serial ports where you want to look for XBee
modules, and click Next.
5. In the Set port parameters window, maintain the default values and click Finish.
6. As XCTU locates radio modules, they appear in the Discovering radio modules dialog box.
If your module could not be found, XCTU displays the Could not find any radio module dialog
providing possible reasons why the module could not be added.

Check for cellular registration and connection
In the following examples, proper cellular network registration and address assignment must occur
successfully. The LED on the development board blinks when the XBee Cellular Modem is registered to
1Six months of free cellular service assumes a rate of 5 Mb/month. If you exceed a limit of 30 Mb during the six

month period your SIM will be deactivated.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with the XBee Cellular Modem Development Kit

Configure the device using XCTU

the cellular network; see The Associate LED. If the LED remains solid, registration has not occurred
properly.
Registration can take several minutes.
Note Make sure you are in an area with adequate cellular network reception or the XBee Cellular
Modem will not make the connection.
Note Check the antenna connections if the device has trouble connecting to the network.
In addition to the LED confirmation, you can check the AT commands below in XCTU to check the
registration and connection. To view these commands:
1. Open XCTU and Add a device.
2. Click the Configuration working mode

button.

3. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.
4. Update to the latest firmware.
Note To search for an AT command in XCTU, use the search box

The relevant commands are:
n AI (Association Indication) reads zero when the device successfully registers to the cellular
network. If it reads 23 it is connecting to the Internet; 22 means it is registering to the cellular
network.
n

MY (Module IP Address) should display a valid IP address. If it reads 0.0.0.0, it has not
registered yet.

Note To read a command's value, click the Read button

next to the command.

Update to the latest firmware
Firmware is the program code stored in the device's persistent memory that provides the control
program for the device. Use XCTU to update the firmware.
Note If you have already updated the firmware in a previous step, this process is not necessary.
1. Click the Configuration working modes button

2. Select a local XBee module from the Radio Modules list.
3. Click the Update firmware button

to ensure you have the most current firmware.

The Update firmware dialog displays the available and compatible firmware for the selected
XBee module.
4. Make sure you check the Force the module to maintain its current configuration box and
then click Update.
5. Select the product family of the XBee module, the function set, and the latest firmware version.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with the XBee Cellular Modem Development Kit

Configure the device using XCTU

6. Click Update. A dialog displays update progress. Click Show details for details of the firmware
update process.
See How to update the firmware of your modules in the XCTU User Guide for more information.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples
The following examples provide some additional scenarios you can try to get familiar with the XBee
Cellular Modem.
Connect to the Echo server
Connect to the ELIZA server
Connect to the Daytime server
Perform a (GET) HTTP request
Get started with CoAP
Connect to a TCP/IP address
Get started with MQTT
Software libraries

Digi XBee Cellular 3G Global Embedded Modem User Guide

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Connection examples

Connect to the Echo server

Connect to the Echo server
This server echoes back the messages you type.
The following table explains the AT commands that you use in this example.
At
command

Value

Description

IP (IP
Protocol)

Set the expected transmission mode to TCP communications.

TD (Text
Delimiter)

D (0x0D)

The text delimiter to be used for Transparent mode, as an ASCII hex
code. No information is sent until this character is entered, unless the
maximum number of characters has been reached. Set to zero to
disable text delimiter checking. Set to D for a carriage return.

DL
52.43.121.77 The target IP address of the echo server.
(Destination
Address)
DE
0x2329
(Destination
Port)

The target port number of the echo server.

To communicate with the Echo server:
1. Ensure that the device is set up correctly with the SIM card installed and the antennas
connected as described in Connect the hardware.
2. Open XCTU and Add a device.
3. Click the Configuration working mode

button.

4. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.
5. To switch to TCP communication, in the IP field, select 1 and click the Write button

6. To enable the XBee Cellular Modem to recognize carriage return as a message delimiter, in the
TD field, type D and click the Write button.
7. To enter the destination address of the echo server, in the DL field, type 52.43.121.77 and click
the Write button.
8. To enter the destination IP port number, in the DE field, type 2329 and click the Write button.
9. Click the Consoles working mode button

on the toolbar to open a serial console to the

device. For instructions on using the Console, see the AT console topic in the XCTU User Guide.
10. Click the Open button

to open a serial connection to the device.

11. Click in the left pane of the Console log, then type in the Console to talk to the echo server.
The following screenshot provides an example of this chat.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Connect to the ELIZA server

Debugging
If you experience problems with the settings in this example, you can load the default settings in
XCTU:
1. On the Configuration toolbar, click the Default button

to load the default values

established by the firmware, and click Yes to confirm.
2. Factory settings are loaded but not written to the device. To write them, click the Write button
on the toolbar.

Connect to the ELIZA server
You can use the XBee Cellular Modem to chat with the ELIZA Therapist Bot. ELIZA is an artificial
intelligence (AI) bot that emulates a therapist and can perform simple conversations.
The following table explains the AT commands that you use in this example.
At command

Value

Description

IP (IP Protocol)

Set the expected transmission mode to TCP
communications.

DL (Destination
Address)

52.43.121.77 The target IP address of the ELIZA server.

DE (Destination Port)

0x2328

The target port number of the ELIZA server.

To communicate with the ELIZA Therapist Bot:
1. Ensure that the device is set up correctly with the SIM card installed and the antennas
connected as described in Connect the hardware.
2. Open XCTU and Add a device.
3. Click the Configuration working mode

button.

4. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Connect to the Daytime server

5. To switch to TCP communication, in the IP field, select 1 and click the Write button

6. To enter the destination address of the ELIZA Therapist Bot, in the DL field, type 52.43.121.77
and click the Write button.
7. To enter the destination IP port number, in the DE field, type 2328 and click the Write button.
8. Click the Consoles working mode button

on the toolbar to open a serial console to the

device. For instructions on using the Console, see the AT console topic in the XCTU User Guide.
9. Click the Open button

to open a serial connection to the device.

10. Click in the left pane of the Console log, then type in the Console to talk to the ELIZA Therapist
Bot. The following screenshot provides an example of this chat with the user's text in blue.

Debugging
If you experience problems with the settings in this example, you can load the default settings in
XCTU:
1. On the Configuration toolbar, click the Default button

to load the default values

established by the firmware, and click Yes to confirm.
2. Factory settings are loaded but not written to the device. To write them, click the Write button
on the toolbar.

Connect to the Daytime server
The Daytime server reports the current Coordinated Universal Time (UTC) value responding to any
user input.
The following table explains the AT commands that you use in this example.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

At
command
IP (IP
Protocol)

Connect to the Daytime server

Value

Description

Set the expected transmission mode to TCP communications.

DL
52.43.121.77 The target IP of the Daytime server.
(Destination
Address)
DE
0x232A
(Destination
Port)

The target port number of the Daytime server.

TD (Text
Delimiter)

To communicate with the Daytime server:
1. Ensure that the device is set up correctly with the SIM card installed and the antennas
connected as described in Connect the hardware.
2. Open XCTU and Add a device.
3. Click the Configuration working mode

button.

4. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.
5. To switch to TCP communication, in the IP field, select 1 and click the Write button

6. To enter the destination address of the daytime server, in the DL field, type 52.43.121.77 and
click the Write button.
7. To enter the destination IP port number, in the DE field, type 232A and click the Write button.
8. To disable text delimiter checking, in the TD field, type 0 and click the Write button.
9. Click the Consoles working mode button

on the toolbar to open a serial console to the

device. For instructions on using the Console, see the AT console topic in the XCTU User Guide.
10. Click the Open button

to open a serial connection to the device.

11. Click in the left pane of the Console log, then type in the Console to query the Daytime server.
The following screenshot provides an example of this chat.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Perform a (GET) HTTP request

Debugging
If you experience problems with the settings in this example, you can load the default settings in
XCTU:
1. On the Configuration toolbar, click the Default button

to load the default values

established by the firmware, and click Yes to confirm.
2. Factory settings are loaded but not written to the device. To write them, click the Write button
on the toolbar.

Perform a (GET) HTTP request
You can use the XBee Cellular Modem to perform a GET Hypertext Transfer Protocol (HTTP) request
using XCTU. HTTP is an application-layer protocol that runs over TCP. This example uses httpbin.org/
as the target website that responds to the HTTP request.
To perform a GET request:
1. Ensure that the device is set up correctly with the SIM card installed and the antennas
connected as described in Connect the hardware.
2. Open XCTU and Add a device.
3. Click the Configuration working mode

button.

4. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.
5. To enter the destination address of the target website, in the DL field, type httpbin.org and
click the Write button

6. To enter the HTTP request port number, in the DE field, type 50 and click the Write button.
Hexadecimal 50 is 80 in decimal.
7. To switch to TCP communication, in the IP field, select 1 and click the Write button.
8. To move into Transparent mode, in the AP field, select 0 and click the Write button.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Get started with CoAP

9. Wait for the AI (Association Indication) value to change to 0 (Connected to the Internet).
10. Click the Consoles working mode button

on the toolbar.

11. From the AT console, click the Add new packet button

in the Send packets dialog. The

Add new packet dialog appears.
12. Enter the name of the data packet.
13. Type the following data in the ASCII input tab:
GET /ip HTTP/1.1
Host: httpbin.org
14. Click the HEX input tab and add 0A (zero A) after each 0D (zero D), and add an additional 0D 0A
at the end of the message body. For example, copy and past the following text into the HEX
input tab:
47 45 54 20 2F 69 70 20 48 54 54 50 2F 31 2E 31 0D 0A 48 6F 73 74 3A 20 68 74 74 70 62 69 6E
2E 6F 72 67 0D 0A 0D 0A
Note The HTTP protocol requires an empty line (a line with nothing preceding the CRLF) to terminate
the request.
15. Click Add packet.
16. Click the Open button

17. Click Send selected packet.
18. A GET HTTP response from httpbin.org appears in the Console log.

Debugging
If you experience problems with the settings in this example, you can load the default settings in
XCTU:
1. On the Configuration toolbar, click the Default button

to load the default values

established by the firmware, and click Yes to confirm.
2. Factory settings are loaded but not written to the device. To write them, click the Write button
on the toolbar.

Get started with CoAP
Constrained Application Protocol (CoAP) is based on UDP connection and consumes low power to
deliver similar functionality to HTTP. This guide contains information about sending GET, POST, PUT
and DELETE operations by using the Coap Protocol with XCTU and Python code working with the XBee
Cellular Modem and Coapthon library (Python 2.7 only).
The Internet Engineering Task Force describes CoAP as:
The protocol is designed for machine-to-machine (M2M) applications such as smart energy and
building automation. CoAP provides a request/response interaction model between application
endpoints, supports built-in discovery of services and resources, and includes key concepts of
the Web such as URIs and Internet media types. CoAP is designed to easily interface with HTTP

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Connection examples

Get started with CoAP

for integration with the Web while meeting specialized requirements such as multicast
support, very low overhead, and simplicity for constrained environments (source).

CoAP terms
When describing CoAP, we use the following terms:
Term

Meaning

Method

COAP's method action is similar to the HTTP method. This guide discusses the GET,
POST, PUT and DELETE methods. With these methods, the XBee Cellular Modem can
transport data and requests.

URI

URI is a string of characters that identifies a resource served at the server.

Token

A token is an identifier of a message. The client uses the token to verify if the received
message is the correct response to its query.

Payload

The message payload is associated with the POST and PUT methods. It specifies the
data to be posted or put to the URI resource.

Message ID The message ID is also an identifier of a message. The client matches the message ID
between the response and query.

CoAP quick start example
The following diagram shows the message format for the CoAP protocol; see ISSN: 2070-1721 for
details:

This is an example GET request:
44 01 C4 09 74 65 73 74 B7 65 78 61 6D 70 6C 65
The following table describes the fields in the GET request.
Field

HEX

Bits

Meaning

Ver

Version 01, which is mandatory here.

Type 0: confirmable.

TKL

0100

Token length: 4.

000 00001

Code: 0.01, which indicates the GET method.

Code

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Get started with CoAP

Field

HEX

Bits

Meaning

Message ID

C4 09

2 Bytes equal
to hex at left

Message ID. The response message will have the
same ID. This can help out identification.

Token

74 65 73 74 4 Bytes equal
to hex at left

Token. The response message will have the same
token. This can help out identification.

Option delta

1011

Delta option: 11 indicates the option data is Uri-Path.

0111

Delta length: 7 indicates there are 7 bytes of data
following as a part of this delta option.

Option length
Option value

65 78 61 6D 7 Bytes equal
70 6C 65
to hex at left

Example.

Configure the device
1. Ensure that the device is set up correctly with the SIM card installed and the antennas
connected as described in Connect the hardware.
2. Open XCTU and click the Configuration working mode

button.

3. Add the XBee Cellular Modem to XCTU; see Add a device.
4. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.
5. To switch to UDP communication, in the IP field, select 0 and click the Write button

6. To set the target IP address that the XBee Cellular Modem will talk to, in the DL field type
52.43.121.77and click the Write button

. A CoAP server is publicly available at address

52.43.121.77.
7. To set the XBee Cellular Modem to send data to port 5683 in decimal, in the DE field, type 1633
and click the Write button.
8. To move into Transparent mode, in the AP field, select 0 and click the Write button.
9. Wait for the AI (Association Indication) value to change to 0 (Connected to the Internet). You
can click Read

to get an update on the AI value.

Example: manually perform a CoAP request
Follow the steps in Configure the device prior to this example. This example performs the CoAP
GET request:
n Method: GET
n

URI: example

Given message token: test

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Get started with CoAP

1. Click the Consoles working mode button

on the toolbar to add a customized packet.

2. From the AT console, click the Add new packet button

in the Send packets dialog. The

Add new packet dialog appears.
3. Click the HEX tab and type the name of the data packet: GET_EXAMPLE.
4. Copy and past the following text into the HEX input tab:
44 01 C4 09 74 65 73 74 B7 65 78 61 6D 70 6C 65
This is the CoAP protocol message decomposed by bytes to perform a GET request on an
example URI with a token test.
5. Click Add packet.
6. Click the Open button

7. Click Send selected packet. The message is sent to the public CoAP server configured in
Configure the device. A response appears in the Console log. Blue text is the query, red text is
the response.
The payload is Get to uri: example, which specifies that this is a successful CoAP GET to URI end
example, which was specified in the query.
Click the Close button to terminate the serial connection.

Example: use Python to generate a CoAP message
This example illustrates how the CoAP protocol can perform GET/POST/PUT/DELETE requests
similarly to the HTTP protocol and how to do this using the XBee Cellular Modem. In this example, the
XBee Cellular Modem talks to a CoAP Digi Server. You can use this client code to provide an abstract
wrapper to generate a CoAP message that commands the XBee Cellular Modem to talk to the remote
CoAP server.
Note It is crucial to configure the XBee Cellular Modem settings. See Configure the device and follow
the steps. You can target the IP address to a different CoAP public server.
1. Install Python 2.7. The Installation guide is located at: python.org/downloads/.
2. Download and install the CoAPthon library in the python environment from
pypi.python.org/pypi/CoAPthon.
3. Download these two .txt files: Coap.txt and CoapParser.txt. After you download them, open the
files in a text editor and save them as .py files.
4. In the folder that you place the Coap.py and CoapParser.py files, press Shift + right-click and
then click Open command window.
5. At the command prompt, type python Coap.py and press Enter to run the program.
6. Type the USB port number that the XBee Cellular Modem is connected to and press Enter. Only
the port number is required, so if the port is COM19, type 19.

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Note If you do not know the port number, open XCTU and look at the XBee Cellular Modem in the
Radio Modules list. This view provides the port number and baud rate, as in the figure below where
the baud rate is 9600 b/s.

7. Type the baud rate and press Enter. You must match the device's current baud rate.
XCTU provides the current baud rate in the BD Baud Rate field. In this example you would type
9600.
8. Press Y if you want an auto-generated example. Press Enter to build your own CoAP request.
9. If you press Y it generates a message with:
n

Method: POST

URI: example

payload: hello world

token: test

The send and receive message must match the same token and message id. Otherwise, the client reattempts the connection by sending out the request.
In the following figure, the payload contains the server response to the query. It shows the results for
when you press Enter rather than Y.

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Connection examples

Connect to a TCP/IP address

Connect to a TCP/IP address
The XBee Cellular Modem can send and receive TCP messages while in Transparent mode; see
Transparent operating mode.
Note You can use this example as a template for sending and receiving data to or from any
TCP/IP server.
The following table explains the AT commands that you use in this example.
Command

Value

Description

IP (IP
Protocol)

Set the expected transmission mode to TCP communication.

DL
(Destination
IP Address)

The target IP address that you send and receive from. For example, a
data logging server’s IP address that you want to send
measurements to.

DE
(Destination
Port)

This is represented as a hexadecimal value.

To connect to a TCP/IP address:
1. Ensure that the device is set up correctly with the SIM card installed and the antennas
connected as described in Connect the hardware.
2. Open XCTU and Add a device.
3. Click the Configuration working mode

button.

4. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.
5. In the IP field, select 1 and click the Write button

6. In the DL field, type the and click the Write button. The target IP address
is the IP address that you send and receive from.
7. In the DE field, type the , converted to hexadecimal, and click the Write
button.
8. Exit Command mode.
After exiting Command mode, any UART data sent to the device is sent to the destination IP address
and port number after the RO (Packetization Timeout) occurs.

Debugging
If you experience problems with the settings in this example, you can load the default settings in
XCTU:
1. On the Configuration toolbar, click the Default button

to load the default values

established by the firmware, and click Yes to confirm.

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Connection examples

Get started with MQTT

2. Factory settings are loaded but not written to the device. To write them, click the Write button
on the toolbar.

Get started with MQTT
MQ Telemetry Transport (MQTT) is a messaging protocol that is ideal for the Internet of Things (IoT)
due to a light footprint and its use of the publish-subscribe model. In this model, a client connects to a
broker, a server machine responsible for receiving all messages, filtering them, and then sending
messages to the appropriate clients.
The first two MQTT examples do not involve the XBee Cellular Modem. They demonstrate using the
MQTT libraries because those libraries are required for Use MQTT over the XBee Cellular Modem with
a PC.
The examples in this guide assume:
n Some knowledge of Python.
n

An integrated development environment (IDE) such as PyCharm, IDLE or something similar.

The examples require:
n An XBee Cellular Modem.
n

A compatible development board, such as the XBIB-U.

XCTU. See Configure the device using XCTU.

That you install Python on your computer. You can download Python from:
https://www.python.org/downloads/.

That you install the pyserial and paho-mqtt libraries to the Python environment. If you use
Python 2, install these libraries from the command line with pip install pyserial and pip
install paho-mqtt. If you use Python 3, use pip3 install pyserial and pip3 install paho-mqtt.

The full MQTT library source code, which includes examples and tests, which is available in the
paho-mqtt github repository at https://github.com/eclipse/paho.mqtt.python. To download this
repository you must have Git installed.

Example: MQTT connect
This example provides insight into the structure of packets in MQTT as well as the interaction
between the client and broker. MQTT uses different packets to accomplish tasks such as connecting,
subscribing, and publishing. You can use XCTU to perform a basic example of sending a broker a
connect packet and receiving the response from the server, without requiring any coding. This is a
good way to see how the client interacts with the broker and what a packet looks like. The following
table is an example connect packet:
Description

Hex value

CONNECT packet fixed header
byte 1

Control packet type

0x10

byte 2

Remaining length

0x10

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Get started with MQTT

Description

Hex value

CONNECT packet variable header
Protocol name
byte 1

Length MSB (0)

0x00

byte 2

Length LSB (4)

0x04

byte 3

(M)

0x4D

byte 4

(Q)

0x51

byte 5

(T)

0x54

byte 6

(T)

0x54

Level (4)

0x04

CONNECT flags byte, see the table below for the bits.

0X02

byte 9

Keep Alive MSB (0)

0X00

byte 10

Keep Alive LSB (60)

0X3C

byte 11

Length MSB (0)

0x00

byte 12

Length LSB (4)

0x04

byte 13

(D)

0x44

byte 14

(I)

0x49

byte 15

(G)

0x47

byte 16

(I)

0x49

Protocol level
byte 7
Connect flags
byte 8
Keep alive

Client ID

The following table describes the fields in the packet:
Field name

Description

Protocol Name The connect packet starts with the protocol name, which is MQTT. The length of
the protocol name (in bytes) is immediately before the name itself.
Protocol Level

Refers to the version of MQTT in use, in this case a value of 4 indicates MQTT
version 3.1.1.

Connect Flags

Indicate certain aspects of the packet. For simplicity, this example only sets the
Clean Session flag, which indicates to the client and broker to discard any previous
session and start a new one.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Get started with MQTT

Field name

Description

Keep Alive

How often the client pings the broker to keep the connection alive; in this example
it is set to 60 seconds.

Client ID

The length of the ID (in bytes) precedes the ID itself. Each client connecting to a
broker must have a unique client ID. In the example, the ID is DIGI. When using the
Paho MQTT Python libraries, a random alphanumeric ID is generated if you do not
specify an ID.

The following table provides the CONNECT flag bits from byte 8, the CONNECT flags byte.
CONNECT Flag Bit(s)

Bit 7

User name flag

Password flag

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Will retain

Will QoS
Will flag

Clean session

Reserved

Send a connect packet
Now that you know what a connect packet looks like, you can send a connect packet to a broker and
view the response. Open XCTU and click the Configuration working mode button.
1. Ensure that the device is set up correctly with the SIM card installed and the antennas
connected as described in Connect the hardware.
2. Open XCTU and click the Configuration working mode

button.

3. Add the XBee Cellular Modem to XCTU; see Add a device.
4. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.
5. In the AP field, set Transparent Mode to [0] if it is not already and click the Write button.
6. In the DL field, type the IP address of the broker you wish to use. This example uses
198.41.30.241, which is the IP address for m2m.eclipse.org, a public MQTT broker.
7. In the DE field, type 75B and set the port that the broker uses. This example uses 75B, because
the default MQTT port is 1883 (0x75B).
8. Once you have entered the required values, click the Write button to write the changes to the
XBee Cellular Modem.
9. Click the Consoles working mode button

on the toolbar to open a serial console to the

device. For instructions on using the Console, see the AT console topic in the XCTU User Guide.

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Connection examples

10. Click the Open button

Get started with MQTT

to open a serial connection to the device.

11. From the AT console, click the Add new packet button

in the Send packets dialog. The

Add new packet dialog appears.
12. Enter the name of the data packet. Name the packet connect_frame or something similar.
13. Click the HEX input tab and type the following (these values are the same values from the
table in Example: MQTT connect):
10 10 00 04 4D 51 54 54 04 02 00 3C 00 04 44 49 47 49

14. Click Add packet. The new packet appears in the Send packets list.
15. Click the packet in the Send packets list.
16. Click Send selected packet.
17. A CONNACK packet response from the broker appears in the Console log. This is a connection
acknowledgment; a successful response should look like this:

You can verify the response from the broker as a CONNACK by comparing it to the structure of a
CONNACK packet in the MQTT documentation, which is available at http://docs.oasisopen.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718081).

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Get started with MQTT

Example: send messages (publish) with MQTT
A basic Python example of a node publishing (sending) a message is:
mqttc = mqtt.Client("digitest") # Create instance of client with client ID
“digitest”
mqttc.connect("m2m.eclipse.org", 1883) # Connect to (broker, port,
keepalive-time)
mqttc.loop_start() # Start networking daemon
mqttc.publish("digitest/test1", "Hello, World!") # Publish message to
“digitest /test1” topic
mqttc.loop_stop() # Kill networking daemon

Note You can easily copy and paste code from the online version of this guide. Use caution with the
PDF version, as it may not maintain essential indentations.
This example imports the MQTT library, allowing you to use the MQTT protocol via APIs in the library,
such as the connect(), subscribe(), and publish() methods.
The second line creates an instance of the client, named mqttc. The client ID is the argument you
passed in: digitest (this is optional).
In line 3, the client connects to a public broker, in this case m2m.eclipse.org, on port 1883 (the default
MQTT port, or 8883 for MQTT over SSL). There are many publicly available brokers available, you can
find a list of them here: https://github.com/mqtt/mqtt.github.io/wiki/brokers.
Line 4 starts the networking daemon with client.loop_start() to handle the background
network/data tasks.
Finally, the client publishes its message Hello, World! to the broker under the topic
digitest/backlog/test1. Any nodes (devices, phones, computers, even microcontrollers) subscribed to
that same topic on the same broker receive the message.
Once no more messages need to be published, the last line stops the network daemon with
client.loop_stop().

Example: receive messages (subscribe) with MQTT
This example describes how a client would receive messages from within a specific topic on the
broker:
import paho.mqtt.client as mqtt
def on_connect(client, userdata, flags, rc): # The callback for when the
client connects to the broker
print("Connected with result code {0}".format(str(rc))) # Print result
of connection attempt
client.subscribe("digitest/test1") # Subscribe to the topic
“digitest/test1”, receive any messages published on it
def on_message(client, userdata, msg): # The callback for when a PUBLISH
message is received from the server.
print("Message received-> " + msg.topic + " " + str(msg.payload)) #
Print a received msg
client = mqtt.Client("digi_mqtt_test")
client ID “digi_mqtt_test”

Digi XBee Cellular 3G Global Embedded Modem User Guide

# Create instance of client with

Connection examples

Get started with MQTT

client.on_connect = on_connect # Define callback function for successful
connection
client.on_message = on_message # Define callback function for receipt of a
message
# client.connect("m2m.eclipse.org", 1883, 60) # Connect to (broker, port,
keepalive-time)
client.connect('127.0.0.1', 17300)
client.loop_forever() # Start networking daemon

Note You can easily copy and paste code from the online version of this guide. Use caution with the
PDF version, as it may not maintain essential indentations.
The first line imports the library functions for MQTT.
The functions on_connect and on_message are callback functions which are automatically called by
the client upon connection to the broker and upon receiving a message, respectively.
The on_connect function prints the result of the connection attempt, and performs the subscription.
It is wise to do this in the callback function as it guarantees the attempt to subscribe happens only
after the client is connected to the broker.
The on_message function prints the received message when it comes in, as well as the topic it was
published under.
In the body of the code, we:
n Instantiate a client object with the client ID digi_mqtt_test.
n

Define the callback functions to use upon connection and upon message receipt.

Connect to an MQTT broker at m2m.eclipse.org, on port 1883 (the default MQTT port, or 8883
for MQTT over SSL) with a keepalive of 60 seconds (this is how often the client pings the broker
to keep the connection alive).

The last line starts a network daemon that runs in the background and handles data transactions and
messages, as well as keeping the socket open, until the script ends.

Use MQTT over the XBee Cellular Modem with a PC
To use this MQTT library over an XBee Cellular Modem, you need a basic proxy that transfers a payload
received via the MQTT client’s socket to the serial or COM port that the XBee Cellular Modem is active
on, as well as the reverse; transfer of a payload received on the XBee Cellular Modem’s serial or COM
port to the socket of the MQTT client. This is simplest with the XBee Cellular Modem in Transparent
mode, as it does not require code to parse or create API frames, and not using API frames means
there is no need for them to be queued for processing.
1. To put the XBee Cellular Modem in Transparent mode, set AP to 0.
2. Set DL to the IP address of the broker you want to use.
3. Set DE to the port to use, the default is 1883 (0x75B). This sets the XBee Cellular Modem to
communicate directly with the broker, and can be performed in XCTU as described in Example:
MQTT connect.
4. You can make the proxy with a dual-threaded Python script, a simple version follows:
import threading
import serial
import socket

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Connection examples

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def setup():
"""
This function sets up the variables needed, including the serial port,
and it's speed/port settings, listening socket, and localhost adddress.
"""
global clisock, cliaddr, svrsock, ser
# Change this to the COM port your XBee Cellular module is using. On
# Linux, this will be /dev/ttyUSB#
comport = 'COM44'
# This is the default serial communication speed of the XBee Cellular
# module
comspeed = 115200
buffer_size = 4096 # Default receive size in bytes
debug_on = 0 # Enables printing of debug messages
toval = None # Timeout value for serial port below
# Serial port object for XBCell modem
ser = serial.Serial(comport,comspeed,timeout=toval)
# Listening socket (accepts incoming connection)
svrsock = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
# Allow address reuse on socket (eliminates some restart errors)
svrsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
clisock = None
cliaddr = None # These are first defined before thread creation
addrtuple = ('127.0.0.1', 17300) # Address tuple for localhost
# Binds server socket to localhost (allows client program connection)
svrsock.bind(addrtuple)
svrsock.listen(1) # Allow (1) connection

def ComReaderThread():
"""
This thread listens on the defined serial port object ('ser') for data
from the modem, and upon receipt, sends it out to the client over the
client socket ('clisock').
"""
global clisock
while (1):
resp = ser.read() ## Read any available data from serial port
print("Received {} bytes from modem.".format(len(resp)))
clisock.sendall(resp) # Send RXd data out on client socket
print("Sent {} byte payload out socket to client.".format(len
(resp)))
def SockReaderThread():
"""
This thread listens to the MQTT client's socket and upon receiving a
payload, it sends this data out on the defined serial port ('ser') to
the
modem for transmission.
"""
global clisock
while (1):
data = clisock.recv(4096) # RX data from client socket
# If the RECV call returns 0 bytes, the socket has closed

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Get started with MQTT

if (len(data) == 0):
print("ERROR - socket has closed. Exiting socket reader
thread.")
return 1 # Exit the thread to avoid a loop of 0-byte receptions
else:
print("Received {} bytes from client via socket.".format(len
(data)))
print("Sending payload to modem...")
bytes_wr = ser.write(data) # Write payload to modem via
UART/serial
print("Wrote {} bytes to modem".format(bytes_wr))
def main():
setup() # Setup the serial port and socket
global clisock, svrsock
if (not clisock): # Accept a connection on 'svrsock' to open 'clisock'
print("Awaiting ACCEPT on server sock...")
(clisock,cliaddr) = svrsock.accept() # Accept an incoming
connection
print("Connection accepted on socket")
# Make thread for ComReader
comthread = threading.Thread(target=ComReaderThread)
comthread.start() # Start the thread
# Make thread for SockReader
sockthread = threading.Thread(target=SockReaderThread)
sockthread.start() # Start the thread
main()

Note This script is a general TCP-UART proxy, and can be used for other applications or scripts that
use the TCP protocol. Its functionality is not limited to MQTT.
Note You can easily copy and paste code from the online version of this guide. Use caution with the
PDF version, as it may not maintain essential indentations.
This proxy script waits for an incoming connection on localhost (127.0.0.1), on port 17300. After
accepting a connection, and creating a socket for that connection (clisock), it creates two threads,
one that reads the serial or COM port that the XBee Cellular Modem is connected to, and one that
reads the socket (clisock), that the MQTT client is connected to.
With:
n

The proxy script running

The MQTT client connected to the proxy script via localhost (127.0.0.1)

The XBee Cellular Modem connected to the machine via USB and properly powered

AP, DL, and DE set correctly

the proxy acts as an intermediary between the MQTT client and the XBee Cellular Modem, allowing
the MQTT client to use the data connection provided by the device.
Think of the proxy script as a translator between the MQTT client and the XBee Cellular Modem. The
following figure shows the basic operation.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Connection examples

Software libraries

The thread that reads the serial port forwards any data received onward to the client socket, and the
thread reading the client socket forwards any data received onward to the serial port. This is
represented in the figure above.
The proxy script needs to be running before running an MQTT publish or subscribe script.
1. With the proxy script running, run the subscribe example from Example: receive messages
(subscribe) with MQTT, but change the connect line from client.connect("m2m.eclipse.org",
1883, 60) to client.connect("127.0.0.1", port=17300, keepalive=20). This connects the
MQTT client to the proxy script, which in turn connects to a broker via the XBee Cellular
Modem’s internet connection.
2. Run the publish example from Example: send messages (publish) with MQTT in a third Python
instance (while the publish script is running you will have three Python scripts running at the
same time).
The publish script runs over your computer’s normal Internet connection, and does not use the XBee
Cellular Modem. You are able to see your published message appear in the subscribe script’s output
once it is received from the broker via the XBee Cellular Modem. If you watch the output of the proxy
script during this process you can see the receptions and transmissions taking place.
The proxy script must be running before you run the subscribe and publish scripts. If you stop the
subscribe script, the socket closes, and the proxy script shows an error. If you try to start the proxy
script after starting the subscribe script, you may also see a socket error. To avoid these errors, it is
best to start the scripts in the correct order: proxy, then subscribe, then publish.

Software libraries
One way to communicate with the XBee device is by using a software library. The libraries available
for use with the XBee Cellular Modem include:
n XBee Java library
n

XBee Python library

The XBee Java Library is a Java API. The package includes the XBee library, its source code and a
collection of samples that help you develop Java applications to communicate with your XBee devices.
The XBee Python Library is a Python API that dramatically reduces the time to market of XBee
projects developed in Python and facilitates the development of these types of applications, making it
an easy process.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with MicroPython
This guide provides an overview of how to use MicroPython with the XBee Cellular Modem. For indepth information and more complex code examples, refer to the Digi MicroPython Programming
Guide. Continue with this guide for simple examples to get started using MicroPython on the XBee
Cellular Modem.

About MicroPython
MicroPython is an open-source programming language based on Python 3, with much of the same
syntax and functionality, but modified to fit on small devices with limited hardware resources, such as
microcontrollers, or in this case, a cellular modem.

Why use MicroPython
MicroPython enables on-board intelligence for simple sensor or actuator applications using digital and
analog I/O. MicroPython can help manage battery life. Cryptic readings can be transformed into useful
data, excess transmissions can be intelligently filtered out, modern sensors and actuators can be
employed directly, and logic can glue inputs and outputs together in an intelligent way.
For more information about MicroPython, see www.micropython.org.
For more information about Python, see www.python.org.

MicroPython on the XBee Cellular Modem
The XBee Cellular Modem has MicroPython running on the device itself. You can access a MicroPython
prompt from the XBee Cellular Modem when you install it in an appropriate development board (XBDB
or XBIB), and connect it to a computer via a USB cable.
Note MicroPython does not work with SPI.
The examples in this guide assume:
n You have XCTU on your computer. See Configure the device using XCTU.
n

You have a terminal program installed on your computer. We recommend using the Use the
MicroPython Terminal in XCTU. This requires XCTU 6.3.7 or higher.

You have an XBee Cellular Modem installed in an appropriate development board such as an
XBIB-U-DEV or an XBIB-2.

Note Most examples in this guide require the XBIB-U-DEV board.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with MicroPython

Use XCTU to enter the MicroPython environment

The XBee Cellular Modem is connected to the computer via a USB cable and XCTU recognizes
it.

The board is powered by an appropriate power supply, 12 VDC and at least 1.1 A.

Use XCTU to enter the MicroPython environment
To use the XBee Cellular Modem in the MicroPython environment:
1. Use XCTU to add the device(s); see Configure the device using XCTU and Add a device.
2. The XBee Cellular Modem appears as a box in the Radio Modules information panel. Each
module displays identifying information about itself.
3. Click this box to select the device and load its current settings.
4. To set the device's baud rate to 115200 b/s, in the BD field select 115200 [7] or higher and
click the Write button

. We recommend using flow control to avoid data loss, especially

when pasting large amounts of code/text.
5. To put the XBee Cellular Modem into MicroPython mode, in the AP field select MicroPython
REPL [4] and click the Write button

6. Note what COM port(s) the XBee Cellular Modem is using, because you will need this
information when you use terminal communication. The Radio Modules information panel lists
the COM port in use.

Use the MicroPython Terminal in XCTU
You can use the MicroPython Terminal to communicate with the XBee Cellular Modem when it is in
MicroPython mode.1 This requires XCTU 6.3.7 or higher. To enter MicroPython mode, follow the steps
in Use XCTU to enter the MicroPython environment. To use the MicroPython Terminal:
1. Click the Tools drop-down menu

and select MicroPython Terminal. The terminal opens.

2. Click Open. If you have not already added devices to XCTU:
a. In the Select the Serial/USB port area, click the COM port that the device uses.
b. Verify that the baud rate and other settings are correct.
3. Click OK. The Open icon changes to Close

, indicating that the device is properly connected.

4. Press Ctrl+B to get the MicroPython version banner and prompt.
You can now type or paste MicroPython commands at the >>> prompt.

Troubleshooting
If you receive No such port: 'Port is already in use by other applications.' in the MicroPython
Terminal close any other console sessions open inside XCTU and close any other serial terminal
programs connected to the device, then retry the MicroPython connection in XCTU.
If the device seems unresponsive, try pressing Ctrl+C to end any running programs.
1See Other terminal programs if you do not use the MicroPython Terminal in XCTU.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with MicroPython

Example: hello world

You can use the +++ escape sequence and look for an OK for confirmation that you have the correct
baud rate.

Example: hello world
1. At the MicroPython >>> prompt, type the Python command: print("Hello, World!")
2. Press Enter to execute the command. The terminal echos back Hello, World!.

Example: turn on an LED
1. Note the DS4 LED on the XBIB board. The following image highlights it in a red box. The LED is
normally off.

2. At the MicroPython >>> prompt, type the commands below, pressing Enter after each one.
After entering the last line of code, the LED illuminates. Anything after a # symbol is a
comment, and you do not need to type it.
Note You can easily copy and paste code from the online version of this guide. Use caution with the
PDF version, as it may not maintain essential indentations.
import machine
from machine import Pin
led = Pin("D4", Pin.OUT, value=0) # Makes a pin object set to output 0.
# One might expect 0 to mean OFF and 1 to mean ON, and this is normally the
case.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with MicroPython

Exit MicroPython mode

# But the LED we are turning on and off is setup as what is# known as
"active low".
# This means setting the pin to 0 allows current to flow through the LED and
then through the pin, to ground.

3. To turn it off, type the following and press Enter:
led.value(1)

You have successfully controlled an LED on the board using basic I/O.

Exit MicroPython mode
To exit MicroPython mode:
1. In the XCTU MicroPython Terminal, click the green Close button

2. Click Close at the bottom of the terminal to exit the terminal.
3. In XCTU's Configuration working mode
the Write button

, change AP API Enable to another mode and click

. We recommend changing to Transparent mode [0], as most of the

examples use this mode.

Other terminal programs
If you do not use the MicroPython Terminal in XCTU, you can use other terminal programs to
communicate with the XBee Cellular Modem. If you use Microsoft Windows, follow the instructions for
Tera Term, if you use Linux, follow the instructions for picocom. To download these programs:
n Tera Term for Windows; see https://ttssh2.osdn.jp/index.html.en.
n

Picocom for Linux; see https://developer.ridgerun.com/wiki/index.php/Setting_up_Picocom_-_
Ubuntu and for the source code and in-depth information https://github.com/npatefault/picocom.

Tera Term for Windows
With the XBee Cellular Modem in MicroPython mode (AP = 4), you can access the MicroPython prompt
using a terminal.
1. Open Tera Term. The Tera Term: New connection window appears.
2. Click the Serial radio button to select a serial connection.
3. From the Port: drop-down menu, select the COM port that the XBee Cellular Modem is
connected to.
4. Click OK. The COMxx - Tera Term VT terminal window appears and Tera Term attempts to
connect to the device at a baud rate of 9600 b/s. The terminal will not allow communication
with the device since the baud rate setting is incorrect. You must change this rate as it was
previously set to 115200 b/s.
5. Click Setup and Serial Port. The Tera Term: Serial port setup window appears.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with MicroPython

Use picocom in Linux

6. In the Tera Term: Serial port setup window, set the parameters to the following values:
n

Port: Shows the port that the XBee Cellular Modem is connected on.

Baud rate: 115200

Data: 8 bit

Parity: none

Stop: 1 bit

Flow control: hardware

Transmit delay: N/A

7. Click OK to apply the changes to the serial port settings. The settings should go into effect
right away.
8. To verify that local echo is not enabled and that extra line-feeds are not enabled:
a. In Tera Term, click Setup and select Terminal.
b. In the New-line area of the Tera Term: Serial port setup window, click the
Receive drop-down menu and select CR if it does not already show that value.
c. Make sure the Local echo box is not checked.
9. Click OK.
10. Press Ctrl+B to get the MicroPython version banner and prompt.

Now you can type MicroPython commands at the >>> prompt.

Use picocom in Linux
With the XBee Cellular Modem in MicroPython mode (AP = 4), you can access the MicroPython prompt
using a terminal.
Note The user must have read and write permission for the serial port the XBee Cellular Modem is
connected to in order to communicate with the device.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Get started with MicroPython

Use picocom in Linux

1. Open a terminal in Linux and type picocom -b 115200 /dev/ttyUSB0. This assumes you have
no other USB-to-serial devices attached to the system.
2. Press Ctrl+B to get the MicroPython version banner and prompt. You can also press Enter to
bring up the prompt.
If you do have other USB-to-serial devices attached:
1. Before attaching the XBee Cellular Modem, check the directory /dev/ for any devices named
ttyUSBx, where x is a number. An easy way to list these is to type: ls /dev/ttyUSB*. This
produces a list of any device with a name that starts with ttyUSB.
2. Take note of the devices present with that name, and then connect the XBee Cellular Modem.
3. Check the directory again and you should see one additional device, which is the XBee Cellular
Modem.
4. In this case, replace /dev/ttyUSB0 at the top with /dev/ttyUSB, where
is the new number that appeared.
5. It should connect and show Terminal ready.

Now you can type MicroPython commands at the >>> prompt.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Technical specifications
Interface and hardware specifications
RF characteristics
Networking specifications
Power requirements
Power consumption
Electrical specifications
Regulatory approvals

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Technical specifications

Interface and hardware specifications

Interface and hardware specifications
The following table provides the interface and hardware specifications for the device.
Specification

Value

Dimensions

2.438 x 3.294 cm (0.960 x 1.297 in)

Weight

5 g (0.18 oz)

Operating temperature

-40 to +85 °C
-30 to +70 °C if 2G fallback mode is enabled

Antenna connector

U.FL

Digital I/O

13 I/O lines

ADC

4 10-bit analog inputs

RF characteristics
The following table provides the RF characteristics for the device.
Specification

Value

Transmit power

Up to 24 dBm, Power Class 3
2G fallback: up to 33 dBm, Power Class 4

Receive sensitivity

Up to -111 dBm

Networking specifications
The following table provides the networking and carrier specifications for the device.
Specification

Value

Addressing
options

TCP/IP, UPD, and SMS

Technology

3G Universal Mobile Telecommunications Service (UMTS)/High Speed Packet
Access (HSPA) with 2G fallback 1

Supported bands Band 19 (800 MHz)
Band 5 (850 MHz)
Band 8 (900 MHz)
Band 2 (1900 MHz)
Band 1 (2100 MHz)
Security

Digi Trustfence™ security with secure boot, encrypted storage, protected JTAG,
SSL/TLS 1.2

1See DO (Device Options) for more information on enabling and using the 2G fallback feature.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Technical specifications

Power requirements

Specification

Value

Downlink/uplink
speeds

Up to 7.2 Mb/s / 5.76 Mb/s

Power requirements
The following table provides the power requirements for the device.
Specification

Value

Normal supply voltage range

3.0 to 5.5 VDC (3.8 to 5 V for 2G fallback mode)

Extended supply voltage range1

2.7 to 5.5 VDC (3.6 to 5.5 VDC for 2G fallback mode)

Power consumption
The peak current was measured from multiple tested units.

Specification

State

Average current (3G
mode)

Connected mode (TX + RX)
current

Active transmit, 24 dBm @ 3.3 V

702 mA

Tx + RX current

Active transmit, 24 dBm @ 5.0 V

425 mA

Rx + ACK current

Active receive @ 3.3 V

224 mA

Rx + ACK current

Active receive @ 5 V

160 mA

Idle current

Idle/connected, listening @ 3.3 V

87 mA

Idle current

Idle/connected, listening @ 5 V

72 mA

Sleep current

Not connected, Deep
Sleep @ 3.3 V

10 µA

Electrical specifications
The following table provides the electrical specifications for the XBee Cellular Modem.

1See the 2G fallback power consumption table for further details.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Technical specifications

Regulatory approvals

Symbol Parameter Condition Min
VCC_IO Internal
supply
voltage for
I/O

While in
deep
sleep and
during
initial
power up

Typical

VCC - 0.3 V or 3.3 V, whichever is
lower

VCC_IO Internal
In normal
supply
running
voltage for mode
I/O

Max

Units

3.3

3.3 V

-0.3

Input
voltage
range on
any I/O pin

VCC_
IO + 0.3

VIL

Input low
voltage

VIH

Input high
voltage

VOL

Voltage
Sinking 1
output low mA, VCC_
IO = 3.3 V

0.05*VCC_
IO

VOH

Voltage
output
high

Sourcing 1
mA, VCC_
IO = 3.3 V

0.9*VCC_
IO

I_IN

Input
leakage
current on
I/O pins

High Z
state; I/O
connected
to Ground
or VCC_IO

0.1

RPU

Internal
pull-up
resistor

Enabled

kΩ

RPD

Internal
pull-down
resistor

Enabled

kΩ

0.3*VCC_ V
IO
0.7*VCC_IO

100

Regulatory approvals
The following table provides the regulatory and carrier approvals for the device.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Technical specifications

Regulatory approvals

Specification

Value

United States

Contains FCC ID: XPY1CGM5NNN

Innovation, Science and Economic Development Canada (ISED)

Contains IC: 8595A-1CGM5NNN

Europe (CE)

Yes

Australia ACMA

Yes, RCM

New Zealand RSM

Yes, R-NZ

RoHS

Lead-free and RoHS compliant

PTCRB certification

Yes

AT&T end device certified

Yes

Digi XBee Cellular 3G Global Embedded Modem User Guide

Hardware
Mechanical drawings
Pin signals
RSSI PWM
SIM card
The Associate LED

Digi XBee Cellular 3G Global Embedded Modem User Guide

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Hardware

Mechanical drawings

Mechanical drawings
The following figures show the mechanical drawings for the XBee Cellular Modem. All dimensions are
in inches.

Pin signals
The pin locations are:

The following table shows the pin assignments for the through-hole device. In the table, low-asserted
signals have a horizontal line above signal name.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Hardware

Pin signals

Name

Direction

Default

Description

Name

Direction

Default

Description

VCC

DOUT

Output

UART Data Out

DIN / CONFIG

Input

UART Data In

DIO12 / SPI_MISO

Either

Disabled

Digital I/O 12 or SPI Slave
Output line

RESET

Input

PWM0 / RSSI / DIO10

Either

Output

PWM Output 0 / RX Signal
Strength Indicator / Digital
I/O 10

DIO11

Either

Disabled

Digital I/O 11

[reserved]

DTR / SLEEP_RQ/ DIO8

GND

DIO4 / SPI_MOSI

Either

Disabled

Digital I/O 4 or SPI Slave
Input Line

CTS / DIO7

Either

Output

Output Clear-to-Send Flow
Control or Digital I/O 7

ON /SLEEP/DIO9

Output

Module Status Indicator or
Digital I/O 9

VREF

Associate / DIO5

Either

Output

Associated Indicator, Digital
I/O 5

RTS / DIO6

Either

Disabled

Input Request-to-Send Flow
Control, Digital I/O 6

AD3 / DIO3 / SPI_SS

Either

Disabled

Analog Input 3 or Digital I/O
3, SPI low enabled select
line

AD2 / DIO2 / SPI_CLK

Either

Disabled

Analog Input 2 or Digital I/O
2, SPI Clock line

AD1 / DIO1 / SPI_ATTN

Either

Disabled

Analog Input 1 or Digital I/O
1, SPI Attention line output

AD0 / DIO0

Either

Input

Analog Input 0, Digital I/O 0

Power supply

Do not connect
Either

Disabled

Pin Sleep Control Line or
Digital I/O 8
Ground

Digi XBee Cellular 3G Global Embedded Modem User Guide

Feature not supported on
this device. Used on other
XBee devices for analog
voltage reference.

Hardware

RSSI PWM

Pin connection recommendations
The recommended minimum pin connections are VCC, GND, DIN, DOUT, RTS, DTR and RESET.
Firmware updates require access to these pins.

RSSI PWM
The XBee Cellular Modem features an RSSI/PWM pin (pin 6) that, if enabled, adjusts the PWM output to
indicate the signal strength of the cellular connection. Use P0 (DIO10/PWM0 Configuration) to enable
the RSSI pulse width modulation (PWM) output on the pin. If P0 is set to 1, the RSSI/PWM pin outputs a
PWM signal where the frequency is adjusted based on the received signal strength of the cellular
connection.
The RSSI/PWM output is enabled continuously unlike other XBee products where the output is enabled
for a short period of time after each received transmission. If running on the XBIB development board,
DIO10 is connected to the RSSI LEDs, which may be interpreted as follows:
Number of LEDs turned
PWM duty cycle on

Received signal strength (dBm)

79.39% or more

-83 dBm or higher

62.42% to
79.39%

-93 to -83 dBm

45.45% to
62.42%

-103 to -93 dBm

Less than
45.45%

Less than -103 dBm, or no cellular network
connection

SIM card
The XBee Cellular Modem uses a 4FF (Nano) size SIM card.
CAUTION! Never insert or remove SIM card while the power is on!

The Associate LED
The following table describes the Associate LED functionality. For the location of the Associate LED on
the XBIB-U development board, see number 6 on the XBIB-U-DEV reference.

LED status
On, solid

Blink
timing

Meaning
Not joined to a mobile network.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Hardware

LED status
Double blink

The Associate LED

Blink
timing

Meaning

½ second The last TCP/UDP/SMS attempt failed. If the LED has this pattern,
you may need to check DI (Remote Manager Indicator) or CI
(Protocol/Connection Indication) for the cause of the error.

Standard single blink 1 second

Normal operation.

The normal association LED signal alternates evenly between high and low as shown below:

Where the low signal means LED off and the high signal means LED on.
When CI is not 0 or 0xFF, the Associate LED has a different blink pattern that looks like this:

Digi XBee Cellular 3G Global Embedded Modem User Guide

Antenna recommendations
Antenna placement

Digi XBee Cellular 3G Global Embedded Modem User Guide

Antenna recommendations

Antenna placement

Antenna placement
For optimal cellular reception, keep the antenna as far away from metal objects and other electronics
(including the XBee Cellular Modem) as possible. Often, small antennas are desirable, but come at the
cost of reduced range and efficiency.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Design recommendations
Power supply considerations
Add a capacitor to the RESET line
Heat considerations

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Design recommendations

Power supply considerations

Power supply considerations
When considering a power supply, use the following design practices.
1. Power supply ripple should be less than 75 mV peak to peak.
2. The power supply should be capable of providing a minimum of 1.5 A at 3.3 V (5 W). Keep in
mind that operating at a lower voltage requires higher current capability from the power
supply to achieve the 5 W requirement.
3. Place sufficient bulk capacitance on the XBee VCC pin to maintain voltage above the minimum
specification during inrush current. Inrush current for VCC = 3.3 V is about 2 A during initial
power up of cellular communications and wakeup from sleep mode. We recommend a
minimum of 220 µF of capacitance on the VCC pin.
4. Place a 10 nF ceramic capacitor very close to the XBee Cellular Modem VCC pin to decrease
high frequency noise.
5. Use a wide power supply trace or power plane to ensure it can handle the peak current
requirements with minimal voltage drop. We recommend that the power supply and trace be
designed such that the voltage at the XBee VCC pin does not vary by more than 0.1 V between
light load (~0.5 W) and heavy load (~3 W).
6. If you use DO (Device Options) to enable 2G fallback mode, the power supply must be capable
of supplying 11.5 W and the minimum input voltage is 3.8 V (for example 3.0 A @ 3.8 V). In
addition, we recommend 1000 µF of bulk capacitance on the VCC pin. The supply should never
drop below 3.6 V during TX bursts.

Add a capacitor to the RESET line
In high EMI noise environments, we recommend adding a 10 nF ceramic capacitor very close to pin 5.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Design recommendations

Heat considerations

Heat considerations
Depending on the use case, your application may require a heat sink. Use a non-conductive thermal
gasket to make contact to the heat sink. The gasket should be thick enough to ensure that contact
with the tallest component does not cause damage when pressure is applied to a secure heat sink.
We recommend connecting the heat sink to the bottom side of the XBee Cellular Modem (SIM card
side). Alternatively, you can attach the heat sink to the top side of the unit (U.FL side), but cooling is
less effective on this side.
We do not recommend operating at hot temperatures without verifying that the device will not
overheat in the operating circumstances.
The operation temperature of the unit can be approximated for different current draws and extreme
cases by the equation below. For best results, attach a temperature probe on the bottom of the XBee
Cellular Modem, about 5 mm higher than the SIM card slot. Alternatively use TP (Temperature) to
query the current temperature of the device's processor.
Where
1. XBeeBoardTemp is the temperature of the XBee Cellular Modem at steady state.
a. Use the TP command to help estimate the temperature when attaching a
temperature probe is not practical, but for reliable results, you must use a
temperature probe.
2. RoomTemp is the temperature of the ambient air.
3. AverageCurrentDuringTest is the average current measured during test.
4. ScenarioMaxCurrent is the maximum current expected for the device.
The results may vary by implementation and scenario. You should always perform sufficient testing to
ensure that the XBee Cellular Modem does not exceed temperature specifications.

Add a fan to provide active cooling
The XBee Cellular Modem can become hot if you use it in the maximum upload or download scenarios,
see Heat considerations. One method of heat mitigation is to attach a fan to the device to provide
active cooling.
If you attach a fan, use P1 (DIO11/PWM1 Configuration) to enable this functionality on pin 7. Set P1 to
1, which turns the fan on when the device gets above 70 °C and the cellular component is running, and
off below 65 °C.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Cellular connection process
Connecting
Data communication with remote servers (TCP/UDP)
Disconnecting
SMS encoding

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Cellular connection process

Connecting

Connecting
In normal operations, the XBee Cellular Modem automatically attempts both a cellular network
connection and a data network connection on power-up. The sequence of these connections is as
follows:

Cellular network
1. The device powers on.
2. It looks for cellular towers.
3. It chooses a candidate tower with the strongest signal.
4. It negotiates a connection.
5. It completes cellular registration; the phone number and SMS are available.

Data network connection
1. The network enables the evolved packet system (EPS) bearer with an access point name
(APN). See AN (Access Point Name) if you have APN issues.
2. The device negotiates a data connection with the access point.
3. The device receives its IP configuration and address.
4. The AI (Association Indication) command now returns a 0 and the sockets become available.

Data communication with remote servers (TCP/UDP)
Once the data network connection is established, communication with remote servers can be
initiated in several ways:
n Transparent mode data sent to the serial port (see TD (Text Delimiter) and RO (Packetization
Timeout) for timing).
n

API mode: Transmit (TX) Request: IPv4 - 0x20 received over the serial connection.

Digi Remote Manager connectivity begins.

Data communication begins when:
1. A socket opens to the remote server.
2. Data is sent.
Data connectivity ends when:
1. The server closes the connection.
2. The TM timeout expires (see TM (IP Client Connection Timeout)).
3. The cellular network may also close the connection after a timeout set by the network
operator.

Disconnecting
When the XBee Cellular Modem is put into Airplane mode or deep sleep is requested:

Digi XBee Cellular 3G Global Embedded Modem User Guide

Cellular connection process

SMS encoding

1. Sockets are closed, cleanly if possible.
2. The cellular connection is shut down.
3. The cellular component is powered off.
Note We recommend entering Airplane mode before resetting or rebooting the device to allow the
cellular module to detach from the network.

SMS encoding
The XBee Cellular Modem transmits SMS messages using the standard GSM 03.38 character set.1
Because this character set only provides 7 bits of space per character, the XBee Cellular Modem
ignores the most significant bit of each octet in an SMS transmission payload.
The device converts incoming SMS messages to ASCII. Characters that cannot be represented in
ASCII are replaced with a space (' ', or 0x20 in hex). This includes emoji and other special characters.

1Also referred to as the GSM 7-bit alphabet.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Modes
Select an operating mode
Transparent operating mode
API operating mode
Bypass operating mode
Command mode
MicroPython mode

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Modes

Select an operating mode

Select an operating mode
The XBee Cellular Modem interfaces to a host device such as a microcontroller or computer through a
logic-level asynchronous serial port. It uses a UART for serial communication with those devices.
The XBee Cellular Modem supports three operating modes: Transparent operating mode,
API operating mode, and Bypass operating mode. The default mode is Transparent operating mode.
Use the AP (API Enable) command to select a different operating mode.
The following flowchart illustrates how the modes relate to each other.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Modes

Transparent operating mode

Transparent operating mode
Devices operate in this mode by default. The device acts as a serial line replacement when it is in
Transparent operating mode. The device queues all serial data it receives through the DIN pin for RF
transmission. When a device receives RF data, it sends the data out through the DOUT pin. You can set
the configuration parameters using Command mode.
The IP (IP Protocol) command setting controls how Transparent operating mode works for the XBee
Cellular Modem.
Note Transparent operation is not available when using SPI.

API operating mode
API operating mode is an alternative to Transparent operating mode. API mode is a frame-based
protocol that allows you to direct data on a packet basis. The device communicates UART or SPI data
in packets, also known as API frames. This mode allows for structured communications with
computers and microcontrollers.
The advantages of API operating mode include:
n It is easier to send information to multiple destinations
n

The host receives the source address for each received data frame

You can change parameters without entering Command mode

Bypass operating mode
CAUTION! Bypass operating mode is an alternative to Transparent and API modes for
advanced users with special configuration needs. Changes made in this mode might
change or disable the device and we do not recommended it for most users.

In Bypass mode, the device acts as a serial line replacement to the cellular component. In this mode,
the XBee Cellular Modem exposes all control of the cellular component's AT port through the UART. If
you use this mode, you must setup the cellular modem directly to establish connectivity. The modem
does not automatically connect to the network.
Note The cellular component can become unresponsive in Bypass mode. See Unresponsive cellular
component in Bypass mode for help in this situation.
When Bypass mode is active, most of the XBee Cellular Modem's AT commands do not work. For
example, IM (IMEI) may never return a value, and DB does not update. In this configuration, the
firmware does not test communication with the cellular component (which it does by sending AT
commands). This is useful in case you have reconfigured the cellular component in a way that makes it
incompatible with the firmware. Bypass operating mode exists for users who wish to communicate
directly with the cellular component settings and do not intend to use XBee Cellular Modem software
features such as API mode.
Command mode is available while in Bypass mode; see Enter Command mode for instructions.

Enter Bypass operating mode
To configure a device for Bypass operating mode:

Digi XBee Cellular 3G Global Embedded Modem User Guide

Modes

Command mode

1. Set the AP (API Enable) parameter value to 5.
2. Send WR (Write) to write the changes.
3. Send FR (Force Reset) to reboot the device.
4. After rebooting, enter Command mode and verify that Bypass operating mode is active by
querying AI (Association Indication) and confirming that it returns a value of 0x2F.
It may take a moment for Bypass operating mode to become active.

Leave Bypass operating mode
To configure a device to leave Bypass operating mode:
1. Set AP (API Enable) to something other than 5.
2. Send WR (Write) to write the changes.
3. Send FR (Force Reset) to reboot the device.
4. After rebooting, enter Command mode and verify that Bypass operating mode is not active by
querying AI (Association Indication) and confirming that it returns a value other than 0x2F.

Restore cellular settings to default in Bypass operating mode
Send AT&F0 to reset the cellular component to its factory profile.

Command mode
Command mode is a state in which the firmware interprets incoming characters as commands. It
allows you to modify the device’s configuration using parameters you can set using AT
commands. When you want to read or set any parameter of the XBee Cellular Modem using this mode,
you have to send an AT command. Every AT command starts with the letters AT followed by the two
characters that identify the command and then by some optional configuration values.
The operating modes of the XBee Cellular Modem are controlled by the AP (API Enable) setting,
but Command mode is always available as a mode the device can enter while configured for any of the
operating modes.
Command mode is available on the UART interface for all operating modes. You cannot use the SPI
interface to enter Command mode.

Enter Command mode
To get a device to switch into Command mode, you must issue the following sequence: +++ within one
second. There must be at least one second preceding and following the +++ sequence. Both the
command character (CC) and the silence before and after the sequence (GT) are configurable. When
the entrance criteria are met the device responds with OK\r on UART signifying that it has entered
Command mode successfully and is ready to start processing AT commands.
If configured to operate in Transparent operating mode, when entering Command mode the XBee
Cellular Modem knows to stop sending data and start accepting commands locally.
Note Do not press Return or Enter after typing +++ because it interrupts the guard time silence and
prevents you from entering Command mode.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Modes

Command mode
When the device is in Command mode, it listens for user input and is able to receive AT commands on
the UART. If CT time (default is 10 seconds) passes without any user input, the device drops out of
Command mode and returns to the previous operating mode. You can force the device to leave
Command mode by sending CN (Exit Command mode).
You can customize the command character, the guard times and the timeout in the device’s
configuration settings. For more information, see CC (Command Sequence Character), CT (Command
Mode Timeout) and GT (Guard Times).

Troubleshooting
Failure to enter Command mode is often due to baud rate mismatch. Ensure that the baud rate of the
connection matches the baud rate of the device. By default, BD (Baud Rate) = 3 (9600 b/s).
There are two alternative ways to enter Command mode:
n A serial break for six seconds enters Command mode. You can issue the "break" command
from a serial console, it is often a button or menu item.
n

Asserting DIN (serial break) upon power up or reset enters Command mode. XCTU guides you
through a reset and automatically issues the break when needed.

Both of these methods temporarily set the device's baud rate to 9600 and return an OK on the UART
to indicate that Command mode is active. When Command mode exits, the device returns to normal
operation at the baud rate that BD is set to.

Send AT commands
Once the device enters Command mode, use the syntax in the following figure to send AT commands.
Every AT command starts with the letters AT, which stands for "attention." The AT is followed by two
characters that indicate which command is being issued, then by some optional configuration values.
To read a parameter value stored in the device’s register, omit the parameter field.

Multiple AT commands
You can send multiple AT commands at a time when they are separated by a comma in Command
mode; for example, ATNIMy XBee,AC.
The preceding example changes the NI (Node Identifier) to My XBee and makes the setting active
through AC (Apply Changes).

Parameter format
Refer to the list of AT commands for the format of individual AT command parameters. Valid formats
for hexidecimal values include with or without a leading 0x for example FFFF or 0xFFFF.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Modes

MicroPython mode

Response to AT commands
When using AT commands to set parameters the XBee Cellular Modem responds with OK if
successful and ERROR if not.
For devices with a file system:
ATAP1
OK
When reading parameters, the device returns the current parameter value instead of an OK message.
ATAP
1

Apply command changes
Any changes you make to the configuration command registers using AT commands do not take effect
until you apply the changes. For example, if you send the BD command to change the baud rate, the
actual baud rate does not change until you apply the changes. To apply changes:
1. Send AC (Apply Changes).
2. Send WR (Write).
or:
3. Exit Command mode.

Make command changes permanent
Send a WR (Write) command to save the changes. WR writes parameter values to non-volatile memory
so that parameter modifications persist through subsequent resets.
Send as RE (Restore Defaults) to wipe settings saved using WR back to their factory defaults.
Note You still have to use WR to save the changes enacted with RE.

Exit Command mode
1. Send CN (Exit Command mode) followed by a carriage return.
or:
2. If the device does not receive any valid AT commands within the time specified by CT
(Command Mode Timeout), it returns to Transparent or API mode. The default Command mode
timeout is 10 seconds.
For an example of programming the device using AT Commands and descriptions of each configurable
parameter, see AT commands.

MicroPython mode
MicroPython mode (AP = 4) allows you to communicate with the XBee Cellular Modem using the
MicroPython programming language. You can use the MicroPython Terminal tool in XCTU to
communicate with the MicroPython stack of the XBee Cellular Modem through the serial interface.
MicroPython mode connects the primary serial port to the stdin/stdout interface on MicroPython,
which is either the REPL or code launched at startup.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Modes

MicroPython mode
When code runs in MicroPython with AP set to a value other than 4, stdout goes to the bit bucket and
there is no input to read on stdin.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Sleep modes
About sleep modes
Normal mode
Pin sleep mode
Cyclic sleep mode
Cyclic sleep with pin wake up mode
Airplane mode
The sleep timer
MicroPython sleep behavior

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Sleep modes

About sleep modes

About sleep modes
A number of low-power modes exist to enable devices to operate for extended periods of time on
battery power. Use SM (Sleep Mode) to enable these sleep modes.

Normal mode
Set SM to 0 to enter Normal mode.
Normal mode is the default sleep mode. If a device is in this mode, it does not sleep and is always
awake.
Devices in Normal mode are typically mains powered.

Pin sleep mode
Set SM to 1 to enter pin sleep mode.
Pin sleep allows the device to sleep and wake according to the state of the SLEEP_RQ pin (pin 9).
When you assert SLEEP_RQ (high), the device finishes any transmit or receive operations, closes any
active connection, and enters a low-power state.
When you de-assert SLEEP_RQ (low), the device wakes from pin sleep.

Cyclic sleep mode
Set SM to 4 to enter Cyclic sleep mode.
Cyclic sleep allows the device to sleep for a specific time and wake for a short time to poll.
If you use the D7 command to enable hardware flow control, the CTS pin asserts (low) when the
device wakes and can receive serial data, and de-asserts (high) when the device sleeps.

Cyclic sleep with pin wake up mode
Set SM to 5 to enter Cyclic sleep with pin wake up mode.
This mode is a slight variation on Cyclic sleep mode (SM = 4) that allows you to wake a device
prematurely by de-asserting the SLEEP_RQ pin (pin 9).
In this mode, you can wake the device after the sleep period expires, or if a high-to-low transition
occurs on the SLEEP_RQ pin.

Airplane mode
While not technically a sleep mode, Airplane mode is another way of saving power. When set, the
cellular component of the XBee Cellular Modem is fully turned off and no access to the cellular
network is performed or possible. Use AM (Airplane Mode) to configure this mode.

The sleep timer
The sleep timer starts when the device wakes and resets on re-configuration. When the sleep timer
expires the device returns to sleep.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Sleep modes

MicroPython sleep behavior

MicroPython sleep behavior
When the XBee Cellular Modem enters Deep Sleep mode, any MicroPython code currently executing is
suspended until the device comes out of sleep. When the XBee Cellular Modem comes out of sleep
mode, MicroPython execution continues where it left off.
Upon entering deep sleep mode, the XBee Cellular Modem closes any active TCP/UDP connections
and turns off the cellular component. As a result, any sockets that were opened in MicroPython prior
to sleep report as no longer being connected. This behavior appears the same as a typical socket
disconnection event will:
n socket.send raises OSError: ENOTCONN
n

socket.sendto raises OSError: ENOTCONN

socket.recv returns the empty string, the traditional end-of-file return value

socket.recvfrom returns an empty message, for example:
(b'', (, ) )
The underlying UDP socket resources have been released at this point.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Serial communication
Serial interface
Serial data
UART data flow
Serial buffers
CTS flow control
RTS flow control

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Serial communication

Serial interface

Serial interface
The XBee Cellular Modem interfaces to a host device through a serial port. The device's serial port can
communicate:
n Through a logic and voltage compatible universal asynchronous receiver/transmitter (UART).
n

Through a level translator to any serial device, for example, through an RS-232 or USB
interface board.

Through a serial peripheral interface (SPI) port.

Serial data
A device sends data to the XBee Cellular Modem's UART through pin 3 DIN as an asynchronous serial
signal. When the device is not transmitting data, the signals should idle high.
For serial communication to occur, you must configure the UART of both devices (the microcontroller
and the XBee Cellular Modem) with compatible settings for the baud rate, parity, start bits, stop bits,
and data bits.
Each data byte consists of a start bit (low), 8 data bits (least significant bit first) and a stop bit (high).
The following diagram illustrates the serial bit pattern of data passing through the device. The
diagram shows UART data packet 0x1F (decimal number 31) as transmitted through the device.

You can configure the UART baud rate, parity, and stop bits settings on the device with the BD, NB,
and SB commands respectively. For more information, see Serial interfacing commands.
In the rare case that a device has been configured with the UART disabled, you can recover the device
to UART operation by holding DIN low at reset time. DIN forces a default configuration on the UART at
9600 baud and it brings the device up in Command mode on the UART port. You can then send the
appropriate commands to the device to configure it for UART operation. If those parameters are
written, the device comes up with the UART enabled on the next reset.

UART data flow
Devices that have a UART interface connect directly to the pins of the XBee Cellular Modem as shown
in the following figure. The figure shows system data flow in a UART-interfaced environment. Lowasserted signals have a horizontal line over the signal name.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Serial communication

Serial buffers

Serial buffers
The XBee Cellular Modem maintains internal buffers to collect serial and RF data that it receives. The
serial receive buffer collects incoming serial characters and holds them until the device can process
them. The serial transmit buffer collects the data it receives via the RF link until it transmits that data
out the serial or SPI port.

CTS flow control
We strongly encourage you to use flow control with the XBee Cellular Modem to prevent buffer
overruns.
CTS flow control is enabled by default; you can disable it with D7 (DIO7/CTS). When the serial receive
buffer fills with the number of bytes specified by FT (Flow Control Threshold), the device de-asserts
CTS (sets it high) to signal the host device to stop sending serial data. The device re-asserts CTS when
less than FT-16 bytes are in the UART receive buffer.
Note Serial flow control is not possible when using the SPI port.

RTS flow control
If you set D6 (DIO6/RTS) to enable RTS flow control, the device does not send data in the serial
transmit buffer out the DOUT pin as long as RTS is de-asserted (set high). Do not de-assert RTS for
long periods of time or the serial transmit buffer will fill.

Digi XBee Cellular 3G Global Embedded Modem User Guide

SPI operation
SPI communications
Full duplex operation
Low power operation
Select the SPI port
Force UART operation
Data format

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SPI operation

SPI communications

SPI communications
The XBee Cellular Modem supports SPI communications in slave mode. Slave mode receives the clock
signal and data from the master and returns data to the master. The following table shows the
signals that the SPI port uses on the device.
Signal

Function

SPI_MOSI
Inputs serial data from the master
(Master Out, Slave In)
SPI_MISO (Master
In, Slave Out)

Outputs serial data to the master

SPI_SCLK
(Serial Clock)

Clocks data transfers on MOSI and MISO

SPI_SSEL
(Slave Select)

Enables serial communication with the slave

SPI_ATTN (Attention) Alerts the master that slave has data queued to send. The XBee Cellular
Modem asserts this pin as soon as data is available to send to the SPI
master and it remains asserted until the SPI master has clocked out all
available data.
In this mode:
n SPI clock rates up to 6 MHz are possible.
n

Data is most significant bit (MSB) first; bit 7 is the first bit of a byte sent over the interface.

Frame Format mode 0 is used. This means CPOL= 0 (idle clock is low) and CPHA = 0 (data is
sampled on the clock’s leading edge).

The SPI port only supports API Mode (AP = 1).

The following diagram shows the frame format mode 0 for SPI communications.

SPI mode is chip to chip communication. We do not supply a SPI communication option on the device
development evaluation boards.

Digi XBee Cellular 3G Global Embedded Modem User Guide

SPI operation

Full duplex operation

Full duplex operation
The specification for SPI includes the four signals SPI_MISO, SPI_MOSI, SPI_CLK, and SPI_SSEL. Using
these four signals, the SPI master cannot know when the slave needs to send and the SPI slave
cannot transmit unless enabled by the master. For this reason, the SPI_ATTN signal is available in the
design. This allows the SPI slave to alert the SPI master that it has data to send. In turn, the SPI
master is expected to assert SPI_SSEL and start SPI_CLK, unless these signals are already asserted
and active respectively. This, in turn, allows the XBee Cellular Modem SPI slave to send data to the
master.
SPI data is latched by the master and slave using the SPI_CLK signal. When data is being transferred
the MISO and MOSI signals change between each clock. If data is not available then these signals will
not change and will be either 0 or 1. This results in receiving either a repetitive 0 or 0xFF. The means
of determining whether or not received data is valid is by packetizing the data with API packets,
without escaping. Valid data to and from the XBee Cellular Modem is delimited by 0x7E, a length, the
payload, and finally a checksum byte. Everything else in both directions should be ignored. The bytes
received between frames will be either 0xff or 0x00. This allows the SPI master to scan for a 0x7E
delimiter between frames.
SPI allows for valid data from the slave to begin before, at the same time, or after valid data begins
from the master. When the master is sending data to the slave and the slave has valid data to send in
the middle of receiving data from the master, it allows a true full duplex operation where data is valid
in both directions for a period of time. During this time, the master and slave must simultaneously
transmit valid data at the clock speed so that no invalid bytes appear within an API frame, causing the
whole frame to be discarded.
An example follows to more fully illustrate the SPI interface during the time valid data is being sent in
both directions. First, the master asserts SPI_SSEL and starts SPI_CLK to send a frame to the slave.
Initially, the slave does not have valid data to send the master. However, while it is still receiving data
from the master, it has its own data to send. Therefore, it asserts SPI_ATTN low. Seeing that SPI_
SSEL is already asserted and that SPI_CLK is active, it immediately begins sending valid data, even
while it is receiving valid data from the master. In this example, the master finishes its valid data
before the slave does. The master will have two indications of valid data: The SPI_ATTN line is
asserted and the API frame length is not yet expired. For both of these reasons, the master should
keep SPI_SSEL asserted and should keep SPI_CLK toggling in order to receive the end of the frame
from the slave, even though these signals were originally turned on by the master to send data.
During the time that the SPI master is sending invalid data to the SPI slave, it is important no 0x7E is
included in that invalid data because that would trigger the SPI slave to start receiving another valid
frame.
The following figure illustrates the SPI interface while valid data is being sent in both directions.

Digi XBee Cellular 3G Global Embedded Modem User Guide

SPI operation

Low power operation

Low power operation
Sleep modes generally work the same on SPI as they do on UART. However, due to the addition of SPI
mode, there is an option of another sleep pin, as described below.
By default, Digi configures DIO8 (SLEEP_REQUEST) as a peripheral and during pin sleep it wakes the
device and puts it to sleep. This applies to both the UART and SPI serial interfaces.
If SLEEP_REQUEST is not configured as a peripheral and SPI_SSEL is configured as a peripheral, then
pin sleep is controlled by SPI_SSEL rather than by SLEEP_REQUEST. Asserting SPI_SSEL (pin 17) by
driving it low either wakes the device or keeps it awake. Negating SPI_SSEL by driving it high puts the
device to sleep.
Using SPI_SSEL to control sleep and to indicate that the SPI master has selected a particular slave
device has the advantage of requiring one less physical pin connection to implement pin sleep on SPI.
It has the disadvantage of putting the device to sleep whenever the SPI master negates SPI_SSEL
(meaning time is lost waiting for the device to wake), even if that was not the intent.
If the user has full control of SPI_SSEL so that it can control pin sleep, whether or not data needs to be
transmitted, then sharing the pin may be a good option in order to make the SLEEP_REQUEST pin
available for another purpose.
If the device is one of multiple slaves on the SPI, then the device sleeps while the SPI master talks to
the other slave, but this is acceptable in most cases.
If you do not configure either pin as a peripheral, then the device stays awake, being unable to sleep in
SM1 mode.

Select the SPI port
To force SPI mode, hold DOUT/DIO13 pin 2 low while resetting the device until SPI_ATTN asserts. This
causes the device to disable the UART and go straight into SPI communication mode. Once
configuration is complete, the device queues a modem status frame to the SPI port, which causes the
SPI_ATTN line to assert. The host can use this to determine that the SPI port is configured properly.
This method forces the configuration to provide full SPI support for the following parameters:
n D1 (This parameter will only be changed if it is at a default of zero when the method is
invoked.)
n

As long as the host does not issue a WR command, these configuration values revert to previous
values after a power-on reset. If the host issues a WR command while in SPI mode, these same
parameters are written to flash. After a reset, parameters that were forced and then written to flash
become the mode of operation.
If the UART is disabled and the SPI is enabled in the written configuration, then the device comes up in
SPI mode without forcing it by holding DOUT low. If both the UART and the SPI are enabled at the time
of reset, then output goes to the UART until the host sends the first input. If that first input comes on
the SPI port, then all subsequent output goes to the SPI port and the UART is disabled. If the first
input comes on the UART, then all subsequent output goes to the UART and the SPI is disabled.
Once you select a serial port (UART or SPI), all subsequent output goes to that port, even if you apply a
new configuration. The only way to switch the selected serial port is to reset the device. On surfacemount devices, forcing DOUT low at the time of reset has no effect. To use SPI mode on the SMT
modules, assert the SPI_SSEL (pin 17) low after reset and before any UART data is input.

Digi XBee Cellular 3G Global Embedded Modem User Guide

SPI operation

Force UART operation

When the master asserts the slave select (SPI_SSEL) signal, SPI transmit data is driven to the output
pin SPI_MISO, and SPI data is received from the input pin SPI_MOSI. The SPI_SSEL pin has to be
asserted to enable the transmit serializer to drive data to the output signal SPI_MISO. A rising edge
on SPI_SSEL causes the SPI_MISO line to be tri-stated such that another slave device can drive it, if so
desired.
If the output buffer is empty, the SPI serializer transmits the last valid bit repeatedly, which may be
either high or low. Otherwise, the device formats all output in API mode 1 format, as described in
Operate in API mode. The attached host is expected to ignore all data that is not part of a formatted
API frame.

Force UART operation
If you configure a device with only the SPI enabled and no SPI master is available to access the SPI
slave port, you can recover the device to UART operation by holding DIN / CONFIG low at reset time.
DIN/CONFIG forces a default configuration on the UART at 9600 baud and brings up the device in
Command mode on the UART port. You can then send the appropriate commands to the device to
configure it for UART operation. If you write those parameters, the device comes up with the UART
enabled on the next reset.

Data format
SPI only operates in API mode 1. The XBee Cellular Modem does not support Transparent mode or API
mode 2 (which escapes control characters). This means that the AP configuration only applies to the
UART, and the device ignores it while using SPI. The reason for this operation choice is that SPI is full
duplex. If data flows in one direction, it flows in the other. Since it is not always possible to have valid
data flowing in both directions at the same time, the receiver must have a way to parse out the valid
data and to ignore the invalid data.
The XBee Cellular Modem sends 0XFF when there is no data to send to the host.

Digi XBee Cellular 3G Global Embedded Modem User Guide

File system
For detailed information about using MicroPython on the XBee Cellular Modem refer to the Digi
MicroPython Programming Guide.
Overview of the file system
XCTU interface
Encrypt files

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File system

Overview of the file system

Overview of the file system
XBee Cellular Modem firmware versions ending in 0B (for example, 1130B, 100B, 3100B) and later
include support for storing files on an internal 1 MB SPI flash.
CAUTION! You need to format the file system if upgrading a device that originally
shipped with older firmware. You can use XCTU, AT commands or MicroPython for that
initial format or to erase existing content at any time.

Note To use XCTU with file system, you need XCTU 6.4.0 or newer.
See ATFS FORMAT confirm and ensure that the format is complete.

Directory structure
The SPI flash appears in the file system as /flash, the only entry at the root level of the file system. It
has a lib directory intended for MicroPython modules and a cert directory for files used for SSL/TLS
sockets.

Paths
The XBee Cellular Modem stores all of its files in the top-level directory /flash. On startup, the ATFS
commands and MicroPython each use that as their current working directory. When specifying the
path to a file or directory, it is interpreted as follows:
n Paths starting with a forward slash are "absolute" and must start with /flash to be valid.
n

All other paths are relative to the current working directory.

The directory .. refers to the parent directory, so an operation on ../filename.txt that takes
place in the directory /flash/test accesses the file /flash/filename.txt.

The directory . refers to the current directory, so the command ATFS ls . lists files in the
current directory.

Names are case-insensitive, so FILE.TXT, file.txt and FiLe.TxT all refer to the same file.

File and directory names are limited to 64 characters, and can only contain letters, numbers,
periods, dashes and underscores. A period at the end of the name is ignored.

The full, absolute path to a file or directory is limited to 255 characters.

Secure files
The file system includes support for secure files with the following properties:
n Created via the ATFS XPUT command or in MicroPython using a mode of * with the open()
method.
n

Unable to download via the ATFS GET command or MicroPython's open() method.

SHA256 hash of file contents available from ATFS HASH command (to compare with a local
copy of a file).

Encrypted on the SPI flash.

Digi XBee Cellular 3G Global Embedded Modem User Guide

File system

XCTU interface

MicroPython can execute code in secure files.

Sockets can use secure files when creating SSL/TLS connections.

XCTU interface
XCTU releases starting with 6.4.0 include a File System Manager in the Tools menu. You can upload
files to and download files from the device, in addition to renaming and deleting existing files and
directories. See the File System manager tool section of the XCTU User Guide for details of its
functionality.

Encrypt files
You can encrypt files on the file system. This provides two things:
1. Protection of the client private key for SSL authentication while it is stored on the XBee
Cellular Modem.
2. Protection for user's MicroPython applications.
Use ATFS XPUT filename to place encrypted files on the file system. The XPUT operation is otherwise
identical to the PUT operation. Files placed in this way are indicated with a pound sign (#) following
the filename. The XBee Cellular Modem does not allow an encrypted file to be read by normal use so it:
1. Cannot be retrieved with the GET operation.
2. Cannot be opened and read in MicroPython applications.
3. Cannot be created by a MicroPython application.
When ATFS HASH filename is run with the filename of an encrypted file, it reports the SHA256 hash of
the file contents. In this way you can validate that the correct file has been placed on the XBee
Cellular Modem.

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Socket behavior

Supported sockets

Supported sockets
The XBee Cellular Modem supports the following number of sockets:
n 7 maximum: some combination of 4 TCP, 4 UDP, 4 SSL.1

Socket timeouts
The XBee Cellular Modem implicitly opens the socket any time there is data to be sent, and closes it
according to the timeout settings. The TM (IP Client Connection Timeout) command controls the
timeout settings.

Socket limits in API mode
There are a fixed number of sockets that can be created which varies by device variant and protocol.
When a Transmit (TX) Request: IPv4 - 0x20 frame is sent to the XBee Cellular Modem for a new
destination, it creates a new socket. The exception to this is when using the UDP protocol with the C0
source port, which allows unlimited destinations on the socket created by C0 (Source Port).
If no more sockets are available, the device sends back a Transmit (TX) Status - 0x89 frame with a
Resource Error.
The Resource Error resolves when an existing socket is closed.
An existing socket may be closed when the socket times out (see TM (IP Client Connection Timeout)
and TS (IP Server Connection Timeout)) or when the socket is closed via a TX request with the CLOSE
flag set.

Enable incoming TCP sockets in API mode
In API mode, you can enable incoming connections to the XBee Cellular Modem.
1. To enable listening, set C0 (Source Port) to the value of the listening port.
2. To use TCP for client and server socket connections, set IP (IP Protocol) to 0x01.
The listener allows multiple clients (incoming connections), up to the limit of the maximum number of
sockets on the system.
When the XBee Cellular Modem receives RF data on the port defined by C0, you get a Receive (RX)
Packet: IPv4 - 0xB0 with the incoming address and port.
If you want to communicate back to the incoming connection, use the Transmit (TX) Request: IPv4 0x20 and enter the received address and port as the destination address and port, along with the
listening (C0) local source port.

API mode behavior for outgoing TCP and SSL connections
To initiate an outgoing TCP or SSL connection to a remote host, send a Transmit (TX) Request: IPv4 0x20 frame to the XBee Cellular Modem's serial port specifying the destination address and
destination port for the remote host; the data is optional and the source port is 0.
If the connection is disconnected at any time, send a Transmit TX Request frame to trigger a new
connection attempt.
To send data over this connection use the Transmit (TX) Request: IPv4 - 0x20.

11 UDP socket is always reserved for DNS, so subtract 1 socket from the values above.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Socket behavior

API mode behavior for outgoing UDP data

The device sends a Transmit (TX) Status - 0x89 frame in reply to the Transmit TX Request indicating
the status of the request. A status of 0 indicates the connection and/or data was successful and a
non-zero value indicates a failure.
Any data received on the connection is sent out the XBee Cellular Modem's serial port as a Receive RX
frame.
A connection is closed when:
n The remote end closes the connection.
n

No data is sent or received for longer than the socket timeout set by TM (IP Client Connection
Timeout).

A Transmit TX Request is sent with the CLOSE flag set.

API mode behavior for outgoing UDP data
To send a UDP datagram to a remote host, send a Transmit (TX) Request: IPv4 - 0x20 frame to the
XBee Cellular Modem's serial port specifying the destination address and destination port of the
remote host. If you use a source port of 0, the device creates a new socket for the purpose of sending
to the remote host. The XBee Cellular Modem supports a finite number of sockets, so if you need to
send to many destinations:
1. The socket must be closed after use.
or
2. You must use the socket specified by the C0 (Source Port) setting.
To use the socket specified by the C0 setting, in the Transmit TX request frame use a source port that
matches the value configured for the C0 setting.
The device sends a Transmit (TX) Status - 0x89 frame in reply to the Transmit TX Request to indicate
the status of the request. A status of 0 indicates the data was successfully sent out of the device and
a non-zero value indicates a failure.
Any data received on the UDP socket is sent out the XBee Cellular Modem's serial port as a Receive
(RX) Packet: IPv4 - 0xB0 frame.
Outgoing UDP transmissions are limited to 1024 byte payloads. Attempting to send over 1024 bytes
results in a TX Status frame with Error type 0x74 (Message too long).
A UDP socket is closed when:
n No data has been sent or received for longer than the socket timeout set by TM (IP Client
Connection Timeout).
n

A transmit TX Request is sent with the CLOSE flag set.

API mode behavior for incoming TCP connections
For incoming connections and data in API mode, the XBee Cellular Modem uses the C0 (Source Port)
and IP (IP Protocol) settings to specify the listening port and protocol used. The XBee Cellular Modem
does not currently support the SSL protocol for incoming connections.
When the IP setting is TCP the XBee Cellular Modem allows multiple incoming TCP connections on the
port specified by the C0 setting. Any data received on the connection is sent out the XBee Cellular
Modem's serial port as a Receive (RX) Packet: IPv4 - 0xB0 frame.
To send data from the device over the connection, use the Transmit (TX) Request: IPv4 - 0x20 frame
with the corresponding address fields received from the Receive RX frame. In other words:

Digi XBee Cellular 3G Global Embedded Modem User Guide

Socket behavior

API mode behavior for incoming UDP data

Take the source address, source port, and destination port fields from the Receive (RX) frame
and use those respectively as:

The destination address, destination port, and source port fields for the Transmit (TX) Request
frame.

A connection is closed when:
n The remote end closes the connection.
n

No data has been sent or received for longer than the socket timeout set by TS (IP Server
Connection Timeout).

A Transmit (TX) Request frame is sent with the CLOSE flag set.

API mode behavior for incoming UDP data
When the IP (IP Protocol) setting is UDP, any data sent from a remote host to the XBee Cellular
Modem's network port specified by the C0 (Source Port) setting is sent out the XBee Cellular Modem's
serial port as a Receive (RX) Packet: IPv4 - 0xB0 frame.
To send data from the XBee Cellular Modem to the remote destination, use the Transmit (TX)
Request: IPv4 - 0x20 frame with the corresponding address fields received from the Receive RX frame.
In other words take the source address, source port, and destination port fields from the Receive (RX)
frame and use those respectively as the destination address, destination port, and source port fields
for the Transmit (TX) Request frame.
Incoming UDP transmissions over 1024 bytes in length are output in multiple API frames. For example,
if a 1500 byte UDP transmission is received first, a frame with a 1024 byte payload is sent out then
another frame with a payload of 476 bytes is output.

Transparent mode behavior for outgoing TCP and SSL
connections
For Transparent mode, the IP (IP Protocol) setting specifies the protocol and the DL (Destination
Address) and DE (Destination Port) settings specify the destination address used for outgoing data
(UDP) and outgoing connections (TCP and SSL).
To initiate an outgoing TCP or SSL connection to a remote host, send data to the XBee Cellular
Modem's serial port. If CI (Protocol/Connection Indication) reports a value of 0, then the connection
was successfully established, otherwise the value of CI indicates why the connection attempt failed.
Any data received over the connection is sent out the XBee Cellular Modem's serial port.
A connection is closed when:
n The remote end closes the connection.
n

No data has been sent or received for longer than the socket timeout set by TM (IP Client
Connection Timeout).

You make and apply a change to the IP, DL, or DE.

Transparent mode behavior for outgoing UDP data
To send outgoing UDP data to a remote host, send data to the XBee Cellular Modem's serial port. If CI
(Protocol/Connection Indication) reports a value of 0, the data was successfully sent; otherwise, the
value of CI indicates why the data failed to be sent.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Socket behavior

Transparent mode behavior for incoming TCP connections

The RO (Packetization Timeout) setting provides some control in how the serial data gets packetized
before being sent to the remote host. The first send opens up a UDP socket used to send and receive
data. Any data received by this socket is sent out the XBee Cellular Modem's serial port.
Note Set RO to FF for realtime typing by humans. Also, see TD (Text Delimiter).

Transparent mode behavior for incoming TCP connections
The C0 (Source Port) and IP (IP Protocol) settings specify the listening port and protocol used for
incoming connections (TCP) and incoming data (UDP) in Transparent mode. SSL is not currently
supported for incoming connections.
When the IP setting is TCP and there is no existing connection to or from the XBee Cellular Modem,
the device accepts one incoming connection. Any data received on the connection is sent out the XBee
Cellular Modem's serial port. Any data sent to the XBee Cellular Modem's serial port is sent over the
connection. If the connection is disconnected, it discards pending data.

Transparent mode behavior for incoming UDP connections
When the IP (IP Protocol) setting is UDP any data sent from a remote host to the XBee Cellular
Modem's network port specified by C0 (Source Port) is sent out the XBee Cellular Modem's serial port.
Any data sent to the XBee Cellular Modem's serial port is sent to the network destination specified by
the DL (Destination Address) and DE (Destination Port) settings. If the DL and DE settings are
unspecified or invalid, the XBee Cellular Modem discards data sent to the serial port.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Transport Layer Security (TLS)
For detailed information about using MicroPython on the XBee Cellular Modem refer to the Digi
MicroPython Programming Guide.
TLS AT commands
Transparent mode and TLS
API mode and TLS
Key formats
Certificate formats
Certificate limitations
Cipher suites
Server Name Indication (SNI)

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Transport Layer Security (TLS)

TLS AT commands

TLS AT commands
The AT commands ATFS (File System), TL (SSL/TLS Protocol Version), IP (IP Protocol), $0 (SSL/TLS
Profile 0), $1 (SSL/TLS Profile 1), and $2 (SSL/TLS Profile 2) support TLS. The format of the $
commands is:
AT$[];[];[]
Where:
n

num: Profile index. Index zero is used for Transparent mode connections and TLS connections
using Transmit (TX) Request: IPv4 - 0x20.

ca_cert: (optional) Filename of a file in the certs/ directory. Indicates the certificate identifying
a trusted root certificate authority (CA) to use in validating servers. If ca_cert is empty the
server certificate is notauthenticated. This must be a single root CA certificate. The modules do
not allow a non-self signed certificate to work, so intermediate CAs are not enough.

client_cert: (optional) Filename of a file in the certs/ directory. Indicates the certificate
presented to servers when requested for client authentication. If client_cert is empty no
certificate is presented to the server should it request one. This may result in mutual
authentication failure.

client_key: (optional) Filename of a file in the certs/ directory. Indicates the private key
matching the public key contained in client_cert. This should be a secure file uploaded with
ATFS XPUT filename. This should always be provided if client_cert is provided and match the
certificate or client authentication will fail.

The default value is ";;". This default value preserves the legacy behavior by allowing the creation of
encrypted connections that are confidential but not authenticated.
To specify a key stored outside of certs/, you can either use a relative path, for example ../server.pem
or an absolute path starting with /flash, for example /flash/server.pem. Both examples refer to the
same file.
It is not an error at configuration time to name a file that does not yet exist. An error is generated if
an attempt to create a TLS connection is made with improper settings.
n Files specified should all be in PEM format, not DER.
n

Upload private keys securely with ATFS XPUT filename.

Certificates can be uploaded with ATFS PUT filename as they are not sensitive. It is not
possible to use ATFS GET filename to GET them if they have been securely uploaded.

To authenticate a server not participating in a public key infrastructure (PKI) using CAs, the server
must present a self-signed certificate. That certificate can be used in the ca_cert field to authenticate
that single server.
There are effectively three levels of authentication provided depending on the parameters provided
1. No authentication: None of the parameters are provided, this is the default value. With this
configuration identity is not validated and a man in the middle (MITM) attack is possible.
2. Server authentication: Only ca_cert is provided. Only the servers identity is checked
3. Mutual authentication: All items are provided and both sides are assured of the identity of their
peer
It is not possible to only have client authentication.

Digi XBee Cellular 3G Global Embedded Modem User Guide

Transport Layer Security (TLS)

Transparent mode and TLS

Transparent mode and TLS
Transparent mode connections made when IP (IP Protocol) = 4 (TLS) are made using the configuration
specified by $0 (SSL/TLS Profile 0).

API mode and TLS
On the Transmit (TX) Request: IPv4 - 0x20 frame, when you specify protocol 4 (TLS), the profile
configuration specified by $0 (SSL/TLS Profile 0) is used to form the TLS connection. Tx Request with
TLS Profile - 0x23 lets you choose the IP setting for the serial data.

Key formats
The RSA PKCS#1 format is the only common format across XBee Cellular device variants. You can
identify a PKCS#1 key file by the presence of BEGIN RSA PRIVATE KEY in the file header.
Digi's implementation does not support encrypted keys, we use file system encryption to protect the
keys at rest in the system.

Certificate formats
The XBee3 Cellular LTE-M Global Smart Modem and the XBee Cellular 3G Global Embedded Modem do
not support X509 v3 certificates and extensions for the client certificate. However, v3 certificates are
fine for CA certificates used in server authentication.

Certificate limitations
The XBee Cellular Modem only supports certificate files that contain a single certificate in them. The
implications of this are:
n For client certificate files (for example when client authentication is required):
l

Self-signed certificates will work.

Certificates signed by the root CA will work, because the root CA can be omitted per RFC
5246. The root certificate authority may be omitted from the chain, under the assumption
that the remote end must already possess it in order to validate it in any case.

Certificate chains that include a intermediate CA are problematic. To work around this the
client's certificate chain has to be supplied to the server outside of the connection.

For server certificate files (when server authentication is required) this is not a problem unless
the client is expected to connect to multiple servers that are using different self signed
certificates or are using certificate chains that are signed by different root CA certificates. To
work around this you have to change the certificates before making the connection, or in the
case of API mode specify a different authentication profile.

Cipher suites
The only documented shared suites between the XBee3 Cellular LTE Cat 1 Smart Modem and the
XBee3 Cellular LTE-M Global Smart Modem are:

Digi XBee Cellular 3G Global Embedded Modem User Guide

Transport Layer Security (TLS)

TLS_RSA_WITH_AES_128_CBC_SHA

TLS_RSA_WITH_AES_256_CBC_SHA

Server Name Indication (SNI)

For the u-blox SARA-R410 and SARA-U201 cellular components:
n TLS_RSA_WITH_AES_128_CBC_SHA
n

TLS_RSA_WITH_AES_128_CBC_SHA256

TLS_RSA_WITH_AES_256_CBC_SHA

TLS_RSA_WITH_AES_256_CBC_SHA256

TLS_RSA_WITH_3DES_EDE_CBC_SHA

Server Name Indication (SNI)
We do not currently support SNI. Therefore servers which use SNI to present certificates based on
client provided host data may be unable to establish the expected connections.

Digi XBee Cellular 3G Global Embedded Modem User Guide

AT commands
Special commands
Cellular commands
Network commands
Addressing commands
Serial interfacing commands
I/O settings commands
I/O sampling commands
Sleep commands
Command mode options
MicroPython commands
Firmware version/information commands
Diagnostic interface commands
Execution commands
File system commands

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AT commands

Special commands

Special commands
The following commands are special commands.

AC (Apply Changes)
Immediately applies new settings without exiting Command mode.
Applying changes means that the device re-initializes based on changes made to its parameter values.
Once changes are applied, the device immediately operates according to the new parameter values.
This behavior is in contrast to issuing the WR (Write) command. The WR command saves parameter
values to non-volatile memory, but the device still operates according to previously saved values until
the device is rebooted or you issue the CN (Exit AT Command Mode) or AC commands.
Parameter range
N/A
Default
N/A

FR (Force Reset)
Resets the device. The device responds immediately with an OK and performs a reset 100 ms later.
If you issue FR while the device is in Command Mode, the reset effectively exits Command mode.
Note We recommend entering Airplane mode before resetting or rebooting the device to allow the
cellular module to detach from the network.
Parameter range
N/A
Default
N/A

RE (Restore Defaults)
Restore device parameters to factory defaults.
The RE command does not write restored values to non-volatile (persistent) memory. Issue the WR
(Write) command after issuing the RE command to save restored parameter values to non-volatile
memory.
Parameter range
N/A
Default
N/A

WR (Write)
Writes parameter values to non-volatile memory so that parameter modifications persist through
subsequent resets.

Digi XBee Cellular 3G Global Embedded Modem User Guide

AT commands

Cellular commands

Note Once you issue a WR command, do not send any additional characters to the device until after
you receive the OK response.
Parameter range
N/A
Default
N/A

Cellular commands
The following AT commands are cellular configuration and data commands.

PH (Phone Number)
Reads the SIM card phone number.
If PH is blank, the XBee Cellular Modem is not registered to the network.
Parameter range
N/A
Default
Set by the cellular carrier via the SIM card

S# (ICCID)
Reads the Integrated Circuit Card Identifier (ICCID) of the inserted SIM.
Parameter range
N/A
Default
Set by the SIM card

IM (IMEI)
Reads the device's International Mobile Equipment Identity (IMEI).
Parameter range
N/A
Default
Set in the factory

MN (Operator)
Reads the network operator on which the device is registered.
Parameter range
N/A

Digi XBee Cellular 3G Global Embedded Modem User Guide

AT commands

Cellular commands

Default
N/A

MV (Modem Firmware Version)
Read the firmware version string for cellular component communications. See the related VR
(Firmware Version) command.
Parameter range
N/A
Default
Set in the currently loaded firmware

DB (Cellular Signal Strength)
Reads the absolute value of the current signal strength to the cell tower in dB. If DB is blank, the XBee
Cellular Modem has not received a signal strength from the cellular component.
Parameter range
0x71 - 0x33 (-113 dBm to -51 dBm) [read-only]
Default
N/A

AN (Access Point Name)
Specifies the packet data network that the modem uses for Internet connectivity. This information is
provided by your cellular network operator. After you set this value, applying changes with AC (Apply
Changes) or CN (Exit Command mode) triggers a network reset.
Parameter range
1 - 100 ASCII characters
Default
-

CP (Carrier Profile)
Configures the cellular component to select network operator settings (RF bands, packet data
configuration) for various networks.
The default setting of 0 (autodetect) increases the boot time.
Changes to the value only take effect on boot so a reboot or power cycle is required for any changes
to become active.
Parameter range
0-3

Digi XBee Cellular 3G Global Embedded Modem User Guide

AT commands

Network commands

Value

Description

Autodetect from inserted ICCID (SIM) [default]

Reserved

AT&T

Verizon

Default
0

AM (Airplane Mode)
When set, the cellular component of the XBee Cellular Modem is fully turned off and no access to the
cellular network is performed or possible.
Parameter range
0-1
0 = Normal operation
1 = Airplane mode
Default
0

Network commands
The following commands are network commands.

IP (IP Protocol)
Sets or displays the IP protocol used for client and server socket connections in IP socket mode.
Parameter range
0-4
Value

Description

0x00

UDP

0x01

TCP

0x02

SMS

0x03

Reserved

0x04

SSL over TCP communication

Default
0x01

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AT commands

Network commands

TL (SSL/TLS Protocol Version)
Sets the SSL/TLS protocol version used for the SSL socket. If you change the TL value, it does not
affect any currently open sockets. The value only applies to subsequently opened sockets.
Note Due to known vulnerabilities in prior protocol versions, we strongly recommend that you use the
latest TLS version whenever possible.
Range
Value

Description

0x00

SSL v3

0x01

TLS v1.0

0x02

TLS v1.1

0x03

TLS v1.2

Default
0x03

$0 (SSL/TLS Profile 0)
Specifies the SSL/TLS certificate(s) to use in Transparent mode (when IP (IP Protocol) = 4) or API
mode (Transmit (TX) Request: IPv4 - 0x20 or Tx Request with TLS Profile - 0x23 with profile set to 0).
Format
server_cert;client_cert;client_key
Parameter range
From 1 through 127 ASCII characters.
Default
N/A

$1 (SSL/TLS Profile 1)
Specifies the SSL/TLS certificate(s) to use for Tx Request with TLS Profile - 0x23 transmissions with
profile set to 1.
Format
server_cert;client_cert;client_key
Parameter range
From 1 through 127 ASCII characters.
Default
N/A

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AT commands

Network commands

$2 (SSL/TLS Profile 2)
Specifies the SSL/TLS certificate(s) to use in Transparent mode (when IP (IP Protocol) = 4) or API
mode (Transmit (TX) Request: IPv4 - 0x20 or Tx Request with TLS Profile - 0x23 with profile set to 0).
Format
server_cert;client_cert;client_key
Parameter range
From 1 through 127 ASCII characters.
Default
N/A

TM (IP Client Connection Timeout)
The IP client connection timeout. If there is no activity for this timeout then the connection is closed. If
TM is 0, the connection is closed immediately after the device sends data.
If you change the TM value while in Transparent Mode, the current connection is immediately closed.
Upon the next transmission, the TM value applies to the newly created socket.
If you change the TM value while in API Mode, the value only applies to subsequently opened sockets.
Parameter range
0 - 0xFFFF [x 100 ms]
Default
0xBB8 (5 minutes)

TS (IP Server Connection Timeout)
The IP server connection timeout. If no activity for this timeout then the connection is closed. When
set to 0 the connection is closed immediately after data is sent.]
Parameter Range
10 - 0xFFFF; (x 100 ms)
Default
3000

DO (Device Options)
Enables and disables special features on the XBee Cellular Modem.
Bit 0 - Remote Manager support
If the XBee Cellular Modem cannot establish a connection with Remote Manager, it waits 30 seconds
before trying again. On each successive connection failure, the wait time doubles (60 seconds, 120,
240, and so on) up to a maximum of 1 hour. This time resets to 30 seconds once the connection to
Remote Manager succeeds or if the device is reset.
Bits 1 - 7
Reserved

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AT commands

Network commands

2G fallback
The XBee Cellular Modem is capable of supporting 2G (GSM/GPRS) fallback when a 3G network is not
available. However, connecting to a 2G network draws bursts of current from the power supply in
excess of 2.5 A. This may cause host equipment, including the standard XBee development board, to
brown out. Therefore, if you enable 2G fallback mode you must observe the special considerations
given in Power supply considerations.
After changing this setting, you must:
1. Use WR (Write) to write all values to flash.
2. Use FR (Force Reset) to reset the device.
3. Wait for the cellular component to be initialized: AI (Association Indication) reaches 0x00.
The following table provides the 2G power consumption at 3.8 V and room temperature.
2G Fallback mode (3.8 V)

Average current

Peak current

GSM connected mode, max TX power (1 TX, 1 RX slot)

220 mA

2.6 A

GPRS connected mode, max TX power (4 TX, 1 RX slot)

700 mA

2.6 A

EDGE connected mode, max TX power (4 TX, 1 RX slot)

280 mA

2.6 A

2G active mode

80 mA

Range
0x00 - 0x03
Bitfield
Bit

Remote Manager

2G fallback

0x00

Disabled

0x01 (default)

Enabled

Disabled

0x02

Disabled

Enabled

0x03

Enabled

Default
0x01

EQ (Remote Manager FQDN)
Sets or display the fully qualified domain name of the Remote Manager server.
Range
From 0 through 63 ASCII characters.
Default
my.devicecloud.com

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AT commands

Addressing commands

Addressing commands
The following AT commands are addressing commands.

SH (Serial Number High)
The upper digits of the unique International Mobile Equipment Identity (IMEI) assigned to this device.
Parameter range
0 - 0xFFFFFFFF [read-only]
Default
N/A

SL (Serial Number Low)
The lower digits of the unique International Mobile Equipment Identity (IMEI) assigned to this device.
Parameter range
0 - 0xFFFFFFFF [read-only]
Default
N/A

MY (Module IP Address)
Reads the device's IP address. This command is read-only because the IP address is assigned by the
mobile network.
In API mode, the address is represented as the binary four byte big-endian numeric value representing
the IPv4 address.
In Transparent or Command mode, the address is represented as a dotted-quad string notation.
Parameter range
0- 15 IPv4 characters
Default
0.0.0.0

P# (Destination Phone Number)
Sets or displays the destination phone number used for SMS when IP (IP Protocol) = 2. Phone numbers
must be fully numeric, 7 to 20 ASCII digits, for example: 8889991234.
P# allows international numbers with or without the + prefix. If you omit + and are dialing
internationally, you need to include the proper International Dialing Prefix for your calling region, for
example, 011 for the United States.
Range
7 - 20 ASCII digits including an optional + prefix
Default
N/A

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AT commands

Addressing commands

N1 (DNS Address)
Displays the IPv4 address of the primary domain name server.
Parameter Range
Read-only
Default
0.0.0.0 (waiting on cellular connection)

N2 (DNS Address)
Displays the IPv4 address of the secondary domain name server.
Parameter Range
Read-only
Default
0.0.0.0 (waiting on cellular connection)

DL (Destination Address)
The destination IPv4 address or fully qualified domain name.
To set the destination address to an IP address, the value must be a dotted quad, for example
XXX.XXX.XXX.XXX.
To set the destination address to a domain name, the value must be a legal Internet host name, for
example remotemanager.digi.com
Parameter range
0 - 128 ASCII characters
Default
0.0.0.0

OD (Operating Destination Address)
Read the destination IPv4 address currently in use by Transparent mode. The value is 0.0.0.0 if no
Transparent IP connection is active.
In API mode, the address is represented as the binary four byte big-endian numeric value representing
the IPv4 address.
In Transparent or Command mode, the address is represented as a dotted-quad string notation.
Parameter range
Default
0.0.0.0

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AT commands

Serial interfacing commands

DE (Destination Port)
Sets or displays the destination IP port number.
Parameter range
0x0 - 0xFFFF
Default
0x2616

C0 (Source Port)
Set or get the port number used to provide the serial communication service. Data received by this
port on the network is transmitted on the XBee Cellular Modem's serial port.
As long as a network connection is established to this port (for TCP) data received on the serial port is
transmitted on the established network connection.
IP (IP Protocol) sets the protocol used when UART is in Transparent or API mode.
For more information on using incoming connections, see Socket behavior.
Parameter range
0 - 0xFFFF
Value

Description

Disabled

Non-0

Enabled on that port

Default
0

LA (Lookup IP Address of FQDN)
Performs a DNS lookup of the given fully qualified domain name (FQDN) and outputs its IP address.
When you issue the command in API mode, the IP address is formatted in binary four byte big-endian
numeric value. In all other cases (for example, Command mode) the format is dotted decimal notation.
Range
Valid FQDN
Default
-

Serial interfacing commands
The following AT commands are serial interfacing commands.

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AT commands

Serial interfacing commands

BD (Baud Rate)
Sets or displays the serial interface baud rate for communication between the device's serial port and
the host.
Modified interface baud rates do not take effect until the XBee Cellular Modem exits Command mode
or you issue AC (Apply Changes). The baud rate resets to default unless you save it with WR (Write) or
by clicking the Write module settings button in XCTU.
Parameter range
Standard baud rates: 0x1 - 0xA
Non-standard baud rates: 0x5B9 to 0x5B8D80 (up to 6 Mb/s)
Parameter

Description

0x1

2400 b/s

0x2

4800 b/s

0x3

9600 b/s

0x4

19200 b/s

0x5

38400 b/s

0x6

57600 b/s

0x7

115200 b/s

0x8

230400 b/s

0x9

460800 b/s

0xA

921600 b/s

Default
0x3 (9600 b/s)

NB (Parity)
Set or read the serial parity settings for UART communications.
Parameter range
0x00 - 0x02
Parameter

Description

0x00

No parity

0x01

Even parity

0x02

Odd parity

Default
0x00

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AT commands

Serial interfacing commands

SB (Stop Bits)
Sets or displays the number of stop bits for UART communications.
Parameter range
0-1
Parameter

Configuration

One stop bit

Two stop bits

Default
0

RO (Packetization Timeout)
Set or read the number of character times of inter-character silence required before transmission
begins when operating in Transparent mode.
RF transmission also starts after 100 bytes (maximum packet size) are received in the DI buffer.
Set RO to 0 to transmit characters as they arrive instead of buffering them into one RF packet.
Parameter range
0 - 0xFF (x character times)
Default
3

TD (Text Delimiter)
The ASCII character used as a text delimiter for Transparent mode. When you select a character,
information received over the serial port in Transparent mode is not transmitted until that character
is received. To use a carriage return, set to 0xD. Set to zero to disable text delimiter checking.
Parameter range
0 - 0xFF
Default
0x0

FT (Flow Control Threshold)
Set or display the flow control threshold.
The device de-asserts CTS when FT bytes are in the UART receive buffer.
Parameter range
0x9D - 0x82D

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AT commands

I/O settings commands

Default
0x681

AP (API Enable)
The API mode setting. The device can format the RF packets it receives into API frames and send
them out the UART. When API is enabled the UART data must be formatted as API frames because
Transparent mode is disabled. See Modes for more information.
Parameter range
0x00 - 0x05
Parameter

Description

0x00

API disabled (operate in Transparent mode)

0x01

API enabled

0x02

API enabled (with escaped control characters)

0x03

N/A

0x04

MicroPython REPL

0x05

Bypass mode

Default
0

I/O settings commands
The following AT commands are I/O settings commands.

D0 (DIO0/AD0)
Sets or displays the DIO0/AD0 configuration (pin 20).
Parameter range
0, 2 - 5
Parameter

Description

Disabled

N/A

Analog input

Digital input

Digital output, default low

Digital output, default high

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AT commands

I/O settings commands

Default
0

D1 (DIO1/AD1)
Sets or displays the DIO1/AD1 configuration (pin 19).
Parameter range
0-6
Parameter

Description

Disabled

SPI_ATTN

ADC

Digital input

Digital output, low

Digital output, high

I2C SCL

Default
0

D2 (DIO2/AD2)
Sets or displays the DIO2/AD2 configuration (pin 18).
Parameter range
0-5
Description
0

Disabled

SPI_CLK

Analog input

Digital input

Digital output, default low

Digital output, default high

Default
0

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AT commands

I/O settings commands

D3 (DIO3/AD3)
Sets or displays the DIO3/AD3 configuration (pin 17).
Parameter range
0-5
Parameter

Description

Disabled

SPI_SSEL

Analog input

Digital input

Digital output, default low

Digital output, default high

Default
0

D4 (DIO4)
Sets or displays the DIO4 configuration (pin 11).
Parameter range
0, 1, 3 - 5
Parameter

Description

Disabled

SPI_MOSI

N/A

Digital input

Digital output, default low

Digital output, default high

Default
0

D5 (DIO5/ASSOCIATED_INDICATOR)
Sets or displays the DIO5/ASSOCIATED_INDICATOR configuration (pin 15).
Parameter range
0, 1, 3 - 5

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I/O settings commands

Parameter

Description

Disabled

Associated LED

N/A

Digital input

Digital output, default low

Digital output, default high

Default
1

D6 (DIO6/RTS)
Sets or displays the DIO6/RTS configuration (pin 16).
Parameter range
0, 1, 3 - 5
Parameter

Description

Disabled

RTS flow control

N/A

Digital input

Digital output, default low

Digital output, default high

Default
0

D7 (DIO7/CTS)
Sets or displays the DIO7/CTS configuration (pin 12).
Parameter range
0, 1, 3 - 5
Parameter

Description

Disabled

CTS flow control

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AT commands

I/O settings commands

Parameter

Description

N/A

Digital input

Digital output, default low

Digital output, default high

Default
0x1

D8 (DIO8/SLEEP_REQUEST)
Sets or displays the DIO8/DTR/SLP_RQ configuration (pin 9).
Parameter range
0, 1, 3 - 5
Parameter

Description

Disabled

SLEEP_REQUEST input

Digital input

Digital output, default low

Digital output, default high

Default
1

D9 (DIO9/ON_SLEEP)
Sets or displays the DIO9/ON_SLEEP configuration (pin 13).
Parameter range
0, 1, 3 - 5
Parameter

Description

Disabled

ON/SLEEP output

Digital input

Digital output, default low

Digital output, default high

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I/O settings commands

Default
1

P0 (DIO10/PWM0 Configuration)
Sets or displays the PWM/DIO10 configuration (pin 6).
This command enables the option of translating incoming data to a PWM so that the output can be
translated back into analog form.
Parameter range
0-5
Parameter

Description

Disabled

RSSI PWM0 output

PWM0 output

Digital input

Digital output, low

Digital output, high

Default
0

P1 (DIO11/PWM1 Configuration)
Sets or displays the DIO11 configuration (pin 7).
Parameter range
0, 1, 3 - 6
Parameter Description
0

Disabled

Fan enable. Output is low when the XBee Cellular Modem is sleeping, turning an
attached fan off when the cellular component is in a power saving mode, and also
during Airplane Mode

Digital input

Digital output, default low

Digital output, default high

I2C SDA

Default
0

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I/O settings commands

P2 (DIO12 Configuration)
Sets or displays the DIO12 configuration (pin 4).
Parameter range
0, 1, 3 - 5
Parameter

Description

Disabled

SPI_MISO

N/A

Digital input

Digital output, default low

Digital output, default high

Default
0

PD (Pull Direction)
The resistor pull direction bit field (1 = pull-up, 0 = pull-down) for corresponding I/O lines that are set
by PR (Pull-up/down Resistor Enable).
If the bit is not set in PR, the device uses PD.
Note Resistors are not applied to disabled lines.
See PR (Pull-up/down Resistor Enable) for bit mappings, which are the same.
Parameter range
0x0 – 0x7FFF
Default
0 – 0x7FFF

PR (Pull-up/down Resistor Enable)
Sets or displays the bit field that configures the internal resistor status for the digital input lines.
Internal pull-up/down resistors are not available for digital output pins, analog input pins, or for
disabled pins.
Use the PD command to specify whether the resistor is pull-up or pull-down.
n If you set a PR bit to 1, it enables the pull-up/down resistor.
n

If you set a PR bit to 0, it specifies no internal pull-up/down resistor.

The following table defines the bit-field map for both the PR and PD commands.

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AT commands

I/O settings commands

Bit

I/O line

Module pin

DIO4

pin 11

DIO3/AD3

pin 17

DIO2/AD2

pin 18

DIO1/AD1

pin 19

DIO0/AD0

pin 20

DIO6/RTS

pin 16

DIO8/SLEEP_REQUEST

pin 9

DIO14/DIN

pin 3

DIO5/ASSOCIATE

pin 15

DIO9/On/SLEEP

pin 13

DIO12

pin 4

DIO10

pin 6

DIO11

pin 7

DIO7/CTS

pin 12

DIO13/DOUT

pin 2

Parameter range
0 - 0x7FFF (bit field)
Default
0x7FFF

M0 (PWM0 Duty Cycle)
Sets the duty cycle of PWM0 (pin 6) for P0 = 2, where a value of 0x200 is a 50% duty cycle.
Before setting the line as an output:
1. Enable PWM0 output (P0 (DIO10/PWM0 Configuration) = 2).
2. Apply the settings (use CN (Exit Command mode) or AC (Apply Changes)).
The PWM period is 42.62 µs and there are 0x03FF (1023 decimal) steps within this period. When M0 = 0
(0% PWM), 0x01FF (50% PWM), 0x03FF (100% PWM), and so forth.
Parameter range
0 - 0x3FF
Default
0

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AT commands

I/O sampling commands

I/O sampling commands
The following AT commands configure I/O sampling parameters.

TP (Temperature)
Displays the temperature of the XBee Cellular Modem in degrees Celsius. The temperature value is
displayed in 8-bit two’s complement format. For example, 0x1A = 26 °C, and 0xF6 = -10 °C.
Parameter range
0 - 0xFF which indicates degrees Celsius displayed in 8-bit two's complement format.
Default
N/A

IS (Force Sample)
When run, IS reports the values of all of the enabled digital and analog input lines. If no lines are
enabled for digital or analog input, the command returns an error.
Command mode
In Command mode, the response value is a multi-line format, individual lines are delimited with
carriage returns, and the entire response terminates with two carriage returns. Each line is a series of
ASCII characters representing a single number in hexadecimal notation. The interpretation of the lines
is:
n Number of samples. For legacy reasons this field always returns 1.
n

Digital channel mask. A bit-mask of all I/O capable pins in the system. The bits set to 1 are
configured for digital I/O and are included in the digital data value below. Pins D0 - D9 are bits 0
- 9, and P0 - P2 are bits 10 - 12.

Analog channel mask. The bits set to 1 are configured for analog I/O and have individual
readings following the digital data field.

Digital data. The current digital value of all the pins set in the digital channel mask, only
present if at least one bit is set in the digital channel mask.

Analog data. Additional lines, one for each set pin in the analog channel mask. Each reading is a
10-bit ADC value for a 2.5 V voltage reference.

API operating mode
In API operating mode, IS immediately returns an OK response.
The API response is ordered identical to the Command mode response with the same fields present.
Each field is a binary number of the size listed in the following table. Multi-byte fields are in big-endian
byte order.
Field

Size

Number of samples

1 byte

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AT commands

Sleep commands

Field

Size

Digital channel mask

2 bytes

Analog chanel mask

1 byte

Samples

2 bytes each

Parameter range
N/A
Default
N/A

Sleep commands
The following AT commands are sleep commands.

SM (Sleep Mode)
Sets or displays the sleep mode of the device.
The sleep mode determines how the device enters and exits a power saving sleep.
Sleep mode is also affected by the SO command, option bit 6. See Sleep modes for more information
about sleep modes.
Parameter range
0, 1, 4, 5
Parameter Description
0

Normal. In this mode the device never sleeps.

Pin Sleep. In this mode the device honors the SLEEP_RQ pin. Set D8 (DIO8/SLEEP_
REQUEST) to the sleep request function: 1.

Cyclic Sleep. In this mode the device repeatedly sleeps for the value specified by SP and
spends ST time awake.

Cyclic Sleep with Pin Wake. In this mode the device acts as in Cyclic Sleep but does not
sleep if the SLEEP_RQ pin is inactive, allowing the device to be kept awake or woken by
the connected system.

Default
0

SP (Sleep Period)
Sets or displays the time to spend asleep in cyclic sleep modes. In Cyclic sleep mode, the node sleeps
with CTS disabled for the sleep time interval, then wakes for the wake time interval.
Parameter range
0x1 - 0x83D600 (x 10 ms)

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Command mode options

Default
0x7530 (5 minutes)

ST (Wake Time)
Sets or displays the time to spend awake in cyclic sleep modes.
Parameter range
0x1 - 0x36EE80 (x 1 ms)
Default
0xEA60 (60 seconds)

Command mode options
The following commands are Command mode option commands.

CC (Command Sequence Character)
The character value the device uses to enter Command mode.
The default value (0x2B) is the ASCII code for the plus (+) character. You must enter it three times
within the guard time to enter Command mode. To enter Command mode, there is also a required
period of silence before and after the command sequence characters of the Command mode
sequence (GT + CC + GT). The period of silence prevents inadvertently entering Command mode.
Parameter range
Recommended: 0x20 - 0x7F (ASCII)
Default
0x2B (the ASCII plus character: +)

CT (Command Mode Timeout)
Sets or displays the Command mode timeout parameter. If a device does not receive any valid
commands within this time period, it returns to Idle mode from Command mode.
Parameter range
2 - 0x1770 (x 100 ms)
Default
0x64 (10 seconds)

CN (Exit Command mode)
Immediately exits Command Mode and applies pending changes.
Note Whether Command mode is exited using the CN command or by CT timing out, changes are
applied upon exit.

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AT commands

MicroPython commands

Parameter range
N/A
Default
N/A

GT (Guard Times)
Set the required period of silence before and after the command sequence characters of the
Command mode sequence (GT + CC + GT). The period of silence prevents inadvertently entering
Command mode.
Parameter range
0x2 - 0x576 (x 1 ms)
Default
0x3E8 (one second)

MicroPython commands
The following commands relate to using MicroPython on the XBee Cellular Modem.

PS (Python Startup)
Sets whether or not the XBee Cellular Modem runs the stored Python code at startup.
Range
0-1
Parameter

Description

Do not run stored Python code at startup.

Run stored Python code at startup.

Default
0

PY (MicroPython Command)
Interact with the XBee Cellular Modem using MicroPython. PY is a command with sub-commands.
These sub-commands are arguments to PY.
PYC(Code Report)
You can store compiled code in flash using the Ctrl-F command from the MicroPython REPL; refer to
the Digi MicroPython Programming Guide. The PYC sub-command reports details of the stored code. In
Command mode, it returns three lines of text, for example:

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AT commands

Firmware version/information commands

source: 1662 bytes (hash=0xC3B3A813)
bytecode: 619 bytes (hash=0x0900DBCE)
compiled: 2017-05-09T15:49:44

The messages are:
n source: the size of the source code used to generate the bytecode and its 32-bit hash.
n

bytecode: the size of bytecode stored in flash and its 32-bit hash. A size of 0 indicates that
there is no stored code.

compiled: a compilation timestamp. A timestamp of 2000-01-01T00:00:00 indicates that the
clock was not set during compilation.

In API mode, PYC returns five 32-bit big-endian values:
n source size
n

source hash

bytecode size

bytecode hash

timestamp as seconds since 2000-01-01T00:00:00

PYD (Delete Code)
PYD interrupts any running code, erases any stored code and then does a soft-reboot on the
MicroPython subsystem.
PYV (Version Report)
Report the MicroPython version.
PY^ (Interrupt Program)
Sends KeyboardInterrupt to MicroPython. This is useful if there is a runaway MicroPython program
and you have filled the stdin buffer. You can enter Command mode (+++) and send ATPY^ to interrupt
the program.
Default
N/A

Firmware version/information commands
The following AT commands are firmware version/information commands.

VR (Firmware Version)
Reads the firmware version on a device.
Parameter range
0 - 0xFFFF [read-only]
Default
Set in firmware

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Firmware version/information commands

VL (Verbose Firmware Version)
Shows detailed version information including the application build date and time.
Parameter range
N/A
Default
Set in firmware

HV (Hardware Version)
Display the hardware version number of the device.
Read the device's hardware version. Use this command to distinguish between different hardware
platforms. The upper byte returns a value that is unique to each device type. The lower byte indicates
the hardware revision.
Parameter range
0 - 0xFFFF [read-only]
Default
Set in firmware

AI (Association Indication)
Reads the Association status code to monitor association progress. The following table provides the
status codes and their meanings.
Status code Meaning
0x00

Connected to the Internet.

0x22

Registering to cellular network.

0x23

Connecting to the Internet.

0x24

The cellular component is missing, corrupt, or otherwise in error. The cellular
component requires a new firmware image.

0x25

Cellular network registration denied.

0x2A

Airplane mode.

0x2F

Bypass mode active.

0xFF

Initializing.

Parameter range
0 - 0xFF [read-only]
Default
N/A

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Diagnostic interface commands

HS (Hardware Series)
Read the device's hardware series number.
Parameter range
N/A
Default
Set in the firmware

CK (Configuration CRC)
Displays the cyclic redundancy check (CRC) of the current AT command configuration settings.
Parameter range
0 - 0xFFFFFFFF
Default
N/A

Diagnostic interface commands
The following AT commands are diagnostic interface commands.

DI (Remote Manager Indicator)
Displays the current Remote Manager status for the XBee.
Range
Value

Description

0x00

Connected

0x01

Before connection to the Internet

0x02

Remote Manager connection in progress

0x03

Disconnecting from Remote Manager

0x04

Not configured for Remote Manager

Default
N/A

CI (Protocol/Connection Indication)
Displays information regarding the last IP connection (when the IP command = 0, 1 or 4) or SMS
transmission (when IP = 2).
The value for this parameter resets to 0xFF when the device switches between IP (IP Protocol)
modes.

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Diagnostic interface commands

When IP is set to 0, 1, or 4 (UDP, TCP, over SSL over TCP), CI resets to 0xFF when you apply changes to
any of the following settings:
n DL (Destination Address)
n

DE (Destination Port)

TM (IP Client Connection Timeout)

When IP is set to 2 (SMS), CI resets to 0xFF when P# (Destination Phone Number) is changed.
The following table provides the parameter's meaning when IP = 0 for UDP connections.
Parameter

Description

0x00

The socket is open.

0x01

Tried to send but could not.

0x02

Invalid parameters (bad IP/host).

0x03

TCP not supported on this cellular component.

0x10

Not registered to the cell network.

0x11

Cellular component not identified yet.

0x12

DNS query lookup failure.

0x13

Socket leak

0x20

Bad handle.

0x21

User closed.

0x22

Unknown server - DNS lookup failed.

0x23

Connection lost.

0x24

Unknown.

0xFF

No known status.

The following table provides the parameter's meaning when IP = 1 or 4 for TCP connections.
Parameter

Description

0x00

The socket is open.

0x01

Tried to send but could not.

0x02

Invalid parameters (bad IP/host).

0x03

TCP not supported on this cellular component.

0x10

Not registered to the cell network.

0x11

Cellular component not identified yet.

0x12

DNS query lookup failure.

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AT commands

Execution commands

Parameter

Description

0x13

Socket leak

0x20

Bad handle.

0x21

User closed.

0x22

No network registration.

0x23

No internet connection.

0x24

No server - timed out on connection.

0x25

Unknown server - DNS lookup failed.

0x26

Connection refused.

0x27

Connection lost.

0x28

Unknown.

0xFF

No known status.

The following table provides the parameter's meaning when IP = 2 for SMS connections.
Parameter

Description

0x00

SMS successfully sent.

0x01

SMS failed to send.

0x02

Invalid SMS parameters - check P# (Destination Phone Number).

0x03

SMS not supported.

0x10

No network registration.

0x11

Cellular component stack error.

0x13

Socket leak

0xFF

No SMS state to report (no SMS messages have been sent).

Parameter range
0 - 0xFF (read-only)
Default
-

Execution commands
The location where most AT commands set or query register values, execution commands execute an
action on the device. Execution commands are executed immediately and do not require changes to
be applied.

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AT commands

File system commands

NR (Network Reset)
NR resets the network layer parameters.
The XBee Cellular Modem responds immediately with an OK on the UART and then causes a network
restart.
If NR = 0, the XBee Cellular Modem tears down any TCP/UDP sockets and resets Internet connectivity.
You can also send NR, which acts like NR = 0.
Parameter range
0
Default
N/A

!R (Modem Reset)
Forces the cellular component to reboot.
CAUTION! This command is for advanced users, and you should only use it if the cellular
component becomes completely stuck while in Bypass mode. Normal users should never
need to run this command. See the FR (Force Reset) command instead.

Range
N/A
Default
N/A

File system commands
To access the file system, Enter Command mode and use the following commands. All commands
block the AT command processor until completed and only work from Command mode; they are not
valid for API mode or MicroPython's xbee.atcmd() method. Commands are case-insensitive as are file
and directory names. Optional parameters are shown in square brackets ([]).
FS is a command with sub-commands. These sub-commands are arguments to FS.
For FS commands, you have to type AT before the command, for example ATFS PWD, ATFS LS and so
forth.

Error responses
If a command succeeds it returns information such as the name of the current working directory or a
list of files, or OK if there is no information to report. If it fails, you see a detailed error message
instead of the typical ERROR response for a failing AT command. The response is a named error code
and a textual description of the error.
Note The exact content of error messages may change in the future. All errors start with a capital E,
followed by one or more uppercase letters and digits, a space, and an description of the error.

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File system commands

If writing your own AT command parsing code, you can determine if an FS command response is an
error by checking if the first letter of the response is capital E.

ATFS (File System)
When sent without any parameters, FS prints a list of supported commands.

ATFS PWD
Prints the current working directory, which always starts with / and defaults to /flash at startup.

ATFS CD directory
Changes the current working directory to directory. Prints the current working directory or an error
if unable to change to directory.

ATFS MD directory
Creates the directory directory. Prints OK if successful or an error if unable to create the requested
directory.

ATFS LS [directory]
Lists files and directories in the specified directory. The directory parameter is optional and defaults
to a period (.), which represents the current directory. The list ends with a blank line.
Entries start with zero or more spaces, followed by filesize or the string for directories, then a
single space character and the name of the entry. Directory names end with a forward slash (/) to
differentiate them from files. Secure files end with a hash mark (#) and you cannot download them.

32
1234

./
../
cert/
lib/
test.txt
secure.bin#

ATFS PUT filename
Starts a YMODEM receive on the XBee Cellular Modem, storing the received file to filename and
ignoring the filename that appears in block 0 of the YMODEM transfer. The XBee Cellular Modem
sends a prompt (Receiving file with YMODEM...) when it is ready to receive, at which point you
should initiate a YMODEM send in your terminal emulator.
If the command is incorrect, the reply will be an error as described in Error responses.

ATFS XPUT filename
Similar to the PUT command, but stores the file securely on the XBee Cellular Modem. See Secure
files for details on what this means.
If the command is incorrect, the reply will be an error as described in Error responses.

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File system commands

ATFS HASH filename
Print a sha256 hash of a secure file uploaded via the XPUT command to allow for verification against a
local copy of the file. On Windows, you can generate a SHA256 hash of a file with the
command certutil -hashfile test.txt SHA256. On Mac and Linux use shasum -b -a 256 test.txt.

ATFS GET filename
Starts a YMODEM send of filename on the XBee device. When it is ready to send, the XBee Cellular
Modem sends a prompt: (Sending file with YMODEM...). When the prompt is sent, you should initiate
a YMODEM receive in your terminal emulator.
If the command is incorrect, the reply will be an error as described in Error responses.

ATFS MV source_path dest_path
Moves or renames the selected file or directory source_path to the new name or location dest_
path. This command fails with an error if source_path does not exist, or dest_path already exists.
Note Unlike a computer's command prompt which moves a file into the dest_path if it is an existing
directory, you must specify the full name for dest_path.

ATFS RM file_or_directory
Removes the file or empty directory specified by file_or_directory. This command fails with an error
if file_or_directory does not exist, is not empty, refers to the current working directory or one of its
parents.

ATFS INFO
Report on the size of the filesystem, showing bytes in use, available, marked bad and total. The report
ends with a blank line, as with most multi-line AT command output. Example output:
204800 used
695296 free
0 bad
900096 total

ATFS FORMAT confirm
Reformats the file system, leaving it with a default directory structure. Pass the word confirm as the
first parameter to confirm the format. The XBee Cellular Modem responds with Formatting..., adds a
period every second until the format is complete and ends the response with a carriage return.

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Operate in API mode
API mode overview
Use the AP command to set the operation mode
API frame format

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API mode overview

API mode overview
As an alternative to Transparent operating mode, you can use API operating mode. API mode provides
a structured interface where data is communicated through the serial interface in organized packets
and in a determined order. This enables you to establish complex communication between devices
without having to define your own protocol. The API specifies how commands, command responses
and device status messages are sent and received from the device using the serial interface or the
SPI interface.
We may add new frame types to future versions of firmware, so build the ability to filter out additional
API frames with unknown frame types into your software interface.

Use the AP command to set the operation mode
Use AP (API Enable) to specify the operation mode:
AP command
setting

Description

AP = 0

Transparent operating mode, UART serial line replacement with API modes
disabled. This is the default option.

AP = 1

API operation.

AP = 2

API operation with escaped characters (only possible on UART).

AP = 3

N/A

AP = 4

MicroPython REPL

AP = 5

Bypass mode. This mode is for direct communication with the underlying chip and
is only for advanced users.

The API data frame structure differs depending on what mode you choose.

API frame format
An API frame consists of the following:
n Start delimeter
n

Length

Frame data

Checksum

API operation (AP parameter = 1)
This is the recommended API mode for most applications. The following table shows the data frame
structure when you enable this mode:

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API frame format

Frame fields

Byte

Description

Start delimiter

0x7E

Length

2-3

Most Significant Byte, Least Significant Byte

Frame data

4 - number (n)

API-specific structure

Checksum

n+1

1 byte

Any data received prior to the start delimiter is silently discarded. If the frame is not received correctly
or if the checksum fails, the XBee replies with a radio status frame indicating the reason for the
failure.

API operation with escaped characters (AP parameter = 2)
Setting API to 2 allows escaped control characters in the API frame. Due to its increased complexity,
we only recommend this API mode in specific circumstances. API 2 may help improve reliability if the
serial interface to the device is unstable or malformed frames are frequently being generated.
When operating in API 2, if an unescaped 0x7E byte is observed, it is treated as the start of a new API
frame and all data received prior to this delimiter is silently discarded. For more information on using
this API mode, see the Escaped Characters and API Mode 2 in the Digi Knowledge base.
API escaped operating mode works similarly to API mode. The only difference is that when working in
API escaped mode, the software must escape any payload bytes that match API frame specific data,
such as the start-of-frame byte (0x7E). The following table shows the structure of an API frame with
escaped characters:
Frame fields

Byte Description

Start delimiter 1

0x7E

Length

2-3

Most Significant Byte, Least Significant Byte

Frame data

4-n

API-specific structure

Checksum

n + 1 1 byte

Characters escaped if needed

Start delimiter field
This field indicates the beginning of a frame. It is always 0x7E. This allows the device to easily detect a
new incoming frame.

Escaped characters in API frames
If operating in API mode with escaped characters (AP parameter = 2), when sending or receiving a
serial data frame, specific data values must be escaped (flagged) so they do not interfere with the
data frame sequencing. To escape an interfering data byte, insert 0x7D and follow it with the byte to
be escaped (XORed with 0x20).
The following data bytes need to be escaped:
n 0x7E: start delimiter
n

0x7D: escape character

0x11: XON

0x13: XOFF

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API frame format

To escape a character:
1. Insert 0x7D (escape character).
2. Append it with the byte you want to escape, XORed with 0x20.
In API mode with escaped characters, the length field does not include any escape characters in the
frame and the firmware calculates the checksum with non-escaped data.

Example: escape an API frame
To express the following API non-escaped frame in API operating mode with escaped characters:
Frame Data
Start delimiter Length Frame type
Checksum
Data
7E
00 0F 17
01 00 13 A2 00 40 AD 14 2E FF FE 02 4E 49 6D
You must escape the 0x13 byte:
1. Insert a 0x7D.
2. XOR byte 0x13 with 0x20: 13 ⊕ 20 = 33
The following figure shows the resulting frame. Note that the length and checksum are the same as
the non-escaped frame.
Frame Data
Start delimiter Length Frame type
Checksum
Data
7E
00 0F 17
01 00 7D 33 A2 00 40 AD 14 2E FF FE 02 4E 49 6D
The length field has a two-byte value that specifies the number of bytes in the frame data field. It does
not include the checksum field.

Length field
The length field is a two-byte value that specifies the number of bytes contained in the frame data
field. It does not include the checksum field.

Frame data
This field contains the information that a device receives or will transmit. The structure of frame data
depends on the purpose of the API frame:
Frame data
Start delimiter

Length

Frame type

0x7E

MSB

LSB

API frame type

Checksum

Data
5

8
Data

...

n+1
Single byte

Frame type is the API frame type identifier. It determines the type of API frame and indicates
how the Data field organizes the information.

Data contains the data itself. This information and its order depend on the what type of frame
that the Frame type field defines.

Multi-byte values are sent big-endian.

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API frame format

Calculate and verify checksums
To calculate the checksum of an API frame:
1. Add all bytes of the packet, except the start delimiter 0x7E and the length (the second and
third bytes).
2. Keep only the lowest 8 bits from the result.
3. Subtract this quantity from 0xFF.
To verify the checksum of an API frame:
1. Add all bytes including the checksum; do not include the delimiter and length.
2. If the checksum is correct, the last two digits on the far right of the sum equal 0xFF.
Example
Consider the following sample data packet: 7E 00 0A 01 01 50 01 00 48 65 6C 6C 6F B8+
Byte(s)

Description

Start delimiter

00 0A

Length bytes

API identifier

API frame ID

50 01

Destination address low

Option byte

48 65 6C 6C 6F

Data packet

Checksum

To calculate the check sum you add all bytes of the packet, excluding the frame delimiter 7E and the
length (the second and third bytes):
7E 00 0A 01 01 50 01 00 48 65 6C 6C 6F B8
Add these hex bytes:
01 + 01 + 50 + 01 + 00 + 48 + 65 + 6C + 6C + 6F = 247
Now take the result of 0x247 and keep only the lowest 8 bits which in this example is 0xC4 (the two
far right digits). Subtract 0x47 from 0xFF and you get 0x3B (0xFF - 0xC4 = 0x3B). 0x3B is the checksum
for this data packet.
If an API data packet is composed with an incorrect checksum, the XBee Cellular Modem will consider
the packet invalid and will ignore the data.
To verify the check sum of an API packet add all bytes including the checksum (do not include the
delimiter and length) and if correct, the last two far right digits of the sum will equal FF.
01 + 01 + 50 + 01 + 00 + 48 + 65 + 6C + 6C + 6F + B8 = 2FF

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API frames
The following sections describe the API frames.
AT Command - 0x08
Transmit (TX) SMS - 0x1F
Transmit (TX) Request: IPv4 - 0x20
Tx Request with TLS Profile - 0x23
AT Command Response - 0x88
Transmit (TX) Status - 0x89
Modem Status - 0x8A
Receive (RX) Packet: SMS - 0x9F
Receive (RX) Packet: IPv4 - 0xB0

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API frames

AT Command - 0x08

AT Command - 0x08
Description
Use this frame to query or set parameters on the local device. Changes this frame makes to device
parameters take effect after executing the AT command.

Format
The following table provides the contents of the frame. For details on frame structure, see API frame
format.
Field
name

Field Data
value type Description

Frame
type

0x08

Byte

Frame ID

Byte

Identifies the data frame for the host to correlate with a subsequent
ACK. If set to 0, the device does not send a response.

AT
command

Byte

Command name: two ASCII characters that identify the AT command.

Parameter
value

Byte

If present, indicates the requested parameter value to set the given
register. If no characters are present, it queries the register.

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Transmit (TX) SMS - 0x1F

Transmit (TX) SMS - 0x1F
Description
Transmit an SMS message. The frame allows international numbers with or without the + prefix. If you
omit + and are dialing internationally, you need to include the proper International Dialing Prefix for
your calling region, for example, 011 for the United States.

Format
The following table provides the contents of the frame. For details on frame structure, see API frame
format.
Field
name

Field value Data type

Description

Frame type 0x1F

Byte

Frame ID

Byte

Reference identifier used to match status responses. 0
disables the TX Status frame.

Options

Byte

Reserved for future use.

Phone
number

20 byte string

String representation of phone number terminated
with a null (0x0) byte. Use numbers and the + symbol
only, no other symbols or letters.

Payload

Variable
Data to send as the body of the SMS message.
(160 characters
maximum)

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API frames

Transmit (TX) Request: IPv4 - 0x20

Transmit (TX) Request: IPv4 - 0x20
Description
A TX Request message causes the device to transmit data in IPv4 format. A TX request frame for a
new destination creates a network socket. After the network socket is established, data from the
network that is received on the socket is sent out the device's serial port in the form of a Receive (RX)
Packet frame.

Format
The following table provides the contents of the frame. For details on frame structure, see API frame
format.

Field name

Field
value Data type Description

Frame type

0x20

Byte

Frame ID

Byte

Reference identifier used to match status responses. 0
disables the TX Status frame.

Destination
address

32-bit big
endian

Destination port

16-bit
big endian

Source port

16-bit
If the source port is 0, the device attempts to send the frame
big endian data using an existing open socket with a destination that
matches the destination address and destination port fields
of this frame. If there is no matching socket, then the device
attempts to open a new socket.
If the source port is non-zero, the device attempts to send
the frame data using an existing open socket with a source
and destination that matches the source port, destination
address, and destination port fields of this frame. If there is
no matching socket, it returns an error.

Protocol

Byte

0 = UDP
1 = TCP
4 = SSL over TCP

Transmit options

Byte
bitfield

Bit fields are offset 0
Bit field 0 - 7. Bits 0, and 2-7 are reserved, bit 1 is not.
BIT 1 =
1 - Terminate the TCP socket after transmission is complete
0 - Leave the socket open. Closed by timeout, see TM (IP
Client Connection Timeout).
Ignore this bit for UDP packets.
All other bits are reserved and should be 0.

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Field name
Payload

Transmit (TX) Request: IPv4 - 0x20

Field
value Data type Description
Variable

Data to be transferred to the destination, may be up to 1500
bytes.

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API frames

Tx Request with TLS Profile - 0x23

Tx Request with TLS Profile - 0x23
Description
The frame gives greater control to the application over the TLS settings used for a connection.
A TX Request with TLS Profile frame implies the use of TLS and behaves similar to the TX Request
(0x20) frame, with the protocol field replaced with a TLS Profile field to choose from the profiles
configured with the $0, $1, and $2 configuration commands.

Format
The following table provides the contents of the frame. For details on frame structure, see API frame
format.

Field name

Field
value Data type Description

Frame type

0x23

Byte

Frame ID

Byte

Reference identifier used to match status responses. 0
disables the TX Status frame.

Destination
address

32-bit big
endian

Destination port

16-bit
big endian

Source port

TLS profile

Byte

Zero-indexed number that indicates the profile as specified
by the corresponding $ command.

Transmit options

Byte
bitfield

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Field name
Payload

Tx Request with TLS Profile - 0x23

Field
value Data type Description
Variable

Data to be transferred to the destination, may be up to 1500
bytes.

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API frames

AT Command Response - 0x88

AT Command Response - 0x88
Description
A device sends this frame in response to an AT Command (0x08) frame. Some commands send back
multiple frames.

Format
The following table provides the contents of the frame. For details on frame structure, see API frame
format.
Field
name

Field Data
value type

Frame
type

0x88

Description

Byte

Frame ID

Byte

Identifies the data frame for the host to correlate with a subsequent
ACK. If set to 0, the device does not send a response.

AT
command

Byte

Command name: two ASCII characters that identify the AT command.

Byte

0 = OK
1 = ERROR
2 = Invalid command
3 = Invalid parameter

Byte

Status

Parameter
value

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Transmit (TX) Status - 0x89

Transmit (TX) Status - 0x89
Description
Indicates the success or failure of a transmit operation.

Format
The following table provides the contents of the frame. For details on frame structure, see API frame
format.
Field name Field value Data type Description
Frame type

0x89

Byte

Frame ID

Byte

Refers to the frame ID specified in a previous transmit
frame

Status

Byte

Status code (see the table below)

The following table shows the status codes.
Code

Description

0x0

Successful transmit

0x21

Failure to transmit to cell network

0x22

Not registered to cell network

0x2c

Invalid frame values (check the phone number)

0x31

Internal error

0x32

Resource error (retry operation later)

0x74

Message too long

0x78

Invalid UDP port

0x79

Invalid TCP port

0x7A

Invalid host address

0x7B

Invalid data mode

0x80

Connection refused

0x81

Socket connection lost

0x82

No server

0x83

Socket closed

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Transmit (TX) Status - 0x89

Code

Description

0x84

Unknown server

0x85

Unknown error

0x86

Invalid TLS configuration (missing file, and so forth)

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Modem Status - 0x8A

Modem Status - 0x8A
Description
Cellular component status messages are sent from the device in response to specific conditions.

Format
The following table provides the contents of the frame. For details on frame structure, see API frame
format.
Field name

Field value

Data type

Frame type

0x8A

Byte

Status

Byte

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Description

0 = Hardware reset or power up
1 = Watchdog timer reset
2 = Registered with cellular network
3 = Unregistered with cellular network
0x0E = Remote Manager connected
0x0F = Remote Manager disconnected

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Receive (RX) Packet: SMS - 0x9F

Receive (RX) Packet: SMS - 0x9F
Description
This XBee Cellular Modem uses this frame when it receives an SMS message.

Format
The following table provides the contents of the frame. For details on frame structure, see API frame
format.
Field
name

Field
value

Data type

Frame
Type

0x9F

Byte

Description

Phone
number

20 byte
string

String representation of the phone number, padded out with
null bytes (0x0).

Payload

Variable

Body of the received SMS message.

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Receive (RX) Packet: IPv4 - 0xB0

Receive (RX) Packet: IPv4 - 0xB0
Description
The XBee Cellular Modem uses this frame when it receives RF data on a network socket that is
created by a TX request frame or configuring C0 (Source Port).

Format
The following table provides the contents of the frame. For details on frame structure, see API frame
format.
Frame data fields

Offset

Description

Frame type

0xB0

IPv4 32-bit source
address

MSB 4

The address in the example below is for a source address of
192.168.0.104.
32-bit big endian.

5
6
7

16-bit destination port

MSB 8
LSB 9

The port that the packet was received on.
16-bit big endian.

16-bit source port

MSB 10 The port that the packet was sent from.
16-bit big endian.
LSB 11

Protocol

MSB 12 0 = UDP
1 = TCP
4 = SSL over TCP

Status

Reserved

Payload

Data received from the source. The maximum size is 1500 bytes.

15
16
17
18

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Configure the XBee Cellular Modem using Digi
Remote Manager
Use Digi Remote Manager (https://remotemanager.digi.com/) to perform the operations in this
section. Each operation requires that you enable Remote Manager with the DO command and that
you connect the XBee Cellular Modem to an access point that has an external Internet connection to
allow access to Digi Remote Manager.
Note Digi is consolidating our cloud services, Digi Device Cloud and Digi Remote Manager®, under the
Remote Manager name. This phased process does not affect device functionality or the functionality
of the web services and other features. However, customers will find that some user interface and
firmware functionality mention both Device Cloud and Digi Remote Manager.
Create a Remote Manager account
Get the XBee Cellular Modem IMEI number
Add a XBee Cellular Modem to Remote Manager
Update the firmware
Update the firmware using web services

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Configure the XBee Cellular Modem using Digi Remote Manager

Create a Remote Manager account

Create a Remote Manager account
Digi Remote Manager is an on-demand service with no infrastructure requirements. Remote devices
and enterprise business applications connect to Remote Manager through standards-based web
services. This section describes how to configure and manage an XBee using Remote Manager. For
detailed information on using Remote Manager, refer to the Remote Manager User Guide, available
via the Documentation tab in Remote Manager.
Before you can manage an XBee with Remote Manager, you must create a Remote Manager account.
To create a Remote Manager account:
1. Go to https://www.digi.com/products/cloud/digi-remote-manager.
2. Click 30 DAY FREE TRIAL/LOGIN.
3. Follow the online instructions to complete account registration. You can upgrade your
Developer account to a paid account at any time.
When you are ready to deploy multiple XBee Cellular Modems in the field, upgrade your account to
access additional Remote Manager features.

Get the XBee Cellular Modem IMEI number
Before adding an XBee to your Remote Manager account inventory, you need to determine the
International Mobile Equipment Identity (IMEI) number for the device. Use XCTU to view the IMEI
number by querying the IM parameter.

Add a XBee Cellular Modem to Remote Manager
To add an XBee to your Remote Manager account inventory, follow these steps:
Go to https://remotemanager.digi.com/.
1. Log in to your account.
2. Click Device Management > Devices.
3. Click Add Devices. The Add Devices dialog appears.
4. Select IMEI #, and type or paste the IMEI number of the XBee you want to add. The IM
(IMEI) command provides this number.

5. Click Add to add the device. The XBee is added to your inventory.
6. Click OK to close the Add Devices dialog and return to the Devices view.

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Update the firmware

Update the firmware
XBee Cellular Modem supports Remote Manager firmware updates. To perform a firmware update:
1. Download the updated firmware file for your device from Digi's support site. This is a zip file
containing .ebin and .mxi files for import.
2. Unzip the file.
3. In your Remote Manager account, click Device Management > Devices.
4. Select the first device you want to update.
5. To select multiple devices (must be of the same type), press the Control key and select
additional devices.
6. Click More in the Devices toolbar and select Update Firmware from the Update category of
the More menu. The Update Firmware dialog appears.
7. Click Browse to select the .ebin file that you unzipped earlier.
8. Click Update Firmware. The updated devices automatically reboot when the updates are
complete.

Update the firmware using web services
Remote Manager supports both synchronous and asynchronous firmware update using web services.
The following examples show how to perform an asynchronous firmware update. See the Remote
Manager documentation for more details on firmware updates.
Note You must use XCTU to update the cellular component's firmware.
1. Download the updated firmware file for your device from Digi's support site. This is a zip file
containing .ebin and .mxi files for import.
2. Unzip the file and locate the .ebin inside the unzipped directory.
3. Send an HTTP SCI request to Remote Manager with the contents of the .ebin file converted to
base64 data; see the following example.

Example: update the XBee firmware synchronously with Python 3.0
import base64
import requests
# Location of firmware image
firmware_path = 'XBXC.ebin'
# Remote Manager device ID of the device being updated
device_id = '00010000-00000000-03526130-70153378'
# Remote Manager username and password
username = "my_Remote_manager_username"
password = "my_remote_manager_password"
url = 'https://remotemanager.digi.com/ws/sci'

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Update the firmware using web services

# Get firmware image
fw_file = open(firmware_path, 'rb')
fw_data = fw_file.read()
fw_data = base64.encodebytes(fw_data).decode('utf-8')
# Form update_firmware request
data = """

{}

""".format(device_id, fw_data)
# Post request
r = requests.post(url, auth=(username, password), data=data)
if (r.status_code != 200) or ("error" in r.content.decode('utf-8')):
print("firmware update failed")
else:
print("firmware update success")

Example: use the device's firmware image to update the XBee
firmware synchronously
To update the XBee firmware synchronously with Python 3.0, but using the device firmware image
already uploaded to Remote Manager, upload the device's *.ebin firmware to Remote Manager:
1. Download the updated firmware file for your device from Digi's support site. This is a zip file
containing .ebin and .mxi files for import.
2. Unzip the file and locate the .ebin inside the unzipped directory.
3. Log in to Remote Manager.
4. Click the Data Services tab.
5. Click Data Files.
6. Click Upload Files; browse and select the *.ebin firmware file to upload it.
7. Send an HTTP SCI request to Remote manager with the path of the .ebin file; see the example
below.
import base64
import requests
# Location of firmware image on Remote Manager
firmware_path = '~/XBXC.ebin'
# Remote Manager device ID of the device being updated
device_id = '00010000-00000000-03526130-70153378'
# Remote Manager username and password
username = "my_remote_manager_username"
password = "my_remote_manager_password"

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Update the firmware using web services

url = 'https://remotemanager.digi.com/ws/sci'
# Form update_firmware request
data = """

{}

""".format(device_id, firmware_path)
# Post request
r = requests.post(url, auth=(username, password), data=data)
if (r.status_code != 200) or ("error" in r.content.decode('utf-8')):
print("firmware update failed")
else:
print("firmware update success")

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Troubleshooting
This section contains troubleshooting steps for the XBee Cellular Modem.
Cannot find the serial port for the device
Correct a macOS Java error
Unresponsive cellular component in Bypass mode
Not on expected network after APN change
Syntax error at line 1
Error Failed to send SMS

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Troubleshooting

Cannot find the serial port for the device

Cannot find the serial port for the device
Condition
In XCTU, the serial port that your device is connected to does not appear.

Solution
1. Click the Discover radio modules button

2. Select all of the ports to be scanned.
3. Click Next and then Finish. A dialog notifies you of the devices discovered and their details.

4. Remove the development board from the USB port and view which port name no longer
appears in the Discover radio devices list of ports. The port name that no longer appears is
the correct port for the development board.

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Troubleshooting

Cannot find the serial port for the device

Other possible issues
Other reasons that the XBee Cellular Modem is not discoverable include:
1. If you accidentally have the loopback pins jumpered.
2. You may not have a driver installed. If you do not have a driver installed, the item will have an
exclamation point icon next to it in the Windows Device Manager.
3. You may not be using an updated FTDI driver.
a. Click here to download the drivers for your operating system.
b. This may require you to reboot your computer.
c. Disconnect the power and USB from the XBIB-U-DEV board and reconnect it.
4. If you have a driver installed and updated but still have issues, on Windows 10 you may have to
enable VCP on the driver; see Enable Virtual COM port (VCP) on the driver.

Enable Virtual COM port (VCP) on the driver
On Windows 10 computers, if XCTU does not see the devices you have attached to a PC, you may need
to enable VCP on the USB driver.
To enable VCP:
1. Click the Search

button.

2. Type Device Manager to search for it.
3. Click Universal Serial Bus controllers.
4. If it displays more than one USB controller, unplug the XBee Cellular Modem and plug it back in
to make sure you choose the correct one.
5. Right-click the USB controller and select Properties; a dialog displays.
6. Select the Advanced tab.
7. Check Load VCP.
8. Click OK.
9. Unplug the board and plug it back in.

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Troubleshooting

Correct a macOS Java error

Correct a macOS Java error
When you use XCTU on macOS computer, you may encounter a Java error.

Condition
When opening XCTU for the first time on a macOS computer, you may see the following error:

Solution
1. Click More info to open a browser window.
2. Click Download to get the file javaforosx.dmg.
3. Double-click on the downloaded javaforosx.dmg.
4. In the dialog, double-click the JavaForOSX.pkg and follow the instructions to install Java.

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Troubleshooting

Unresponsive cellular component in Bypass mode

Unresponsive cellular component in Bypass mode
When in Bypass mode, the XBee Cellular Modem does not automatically reset or reboot the cellular
component if it becomes unresponsive.

Condition
In Bypass mode, the XBee Cellular Modem does not respond to commands.

Solution
1. Query the AI (Association Indication) parameter to determine whether the cellular component
is connected to the XBee Cellular Modem software. If AI is 0x2F, Bypass mode should work. If
not, look at the status codes in AI (Association Indication) for guidance.
2. You can send the !R (Modem Reset) command to reset only the cellular component.

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Troubleshooting

Not on expected network after APN change

Not on expected network after APN change
Condition
The XBee Cellular Modem is not on the expected network after a change to the AN (Access Point
Name) command.

Solution
Send ATNR0 to reset Internet connectivity. See NR (Network Reset) for more information.

Syntax error at line 1
You may get a syntax error at line 1 error after pasting example MicroPython code and pressing
Ctrl+D.

Solution
This commonly happens when you accidentally type a character at the beginning of line 1 before
pasting the code.

Error Failed to send SMS
In MicroPython, you consistently get Error Failed to send SMS messages.

Solution
Your device cannot connect to the cell network. The reason may be:
1. The antenna is improperly or loosely connected.
2. The device is at a location where cellular service cannot reach. If the device is connected to the
network, the red LED blinks about twice in a second. If it is not connected it does not blink; see
The Associate LED.
3. You SIM card is out of SMS text quota.
4. The device is not getting enough current, for example if power is being supplied only by USB to
the XBIB development board, rather than using an additional external power supply.

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Regulatory information
Modification statement
Interference statement
Antennas
FCC Class B digital device notice
Labeling requirements for the host device
Europe (CE)
ACMA (Australia)
RSM (New Zealand)

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158

Regulatory information

Modification statement

Modification statement
Digi International has not approved any changes or modifications to this device by the user. Any
changes or modifications could void the user’s authority to operate the equipment.
Digi International n’approuve aucune modification apportée à l’appareil par l’utilisateur, quelle qu’en soit
la nature. Tout changement ou modification peuvent annuler le droit d’utilisation de l’appareil par
l’utilisateur.

Interference statement
This device complies with Part 15 of the FCC Rules and Industry Canada license-exempt RSS standard
(s). Operation is subject to the following two conditions: (1) this device may not cause interference,
and (2) this device must accept any interference, including interference that may cause undesired
operation of the device.
Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de
licence. L'exploitation est autorisée aux deux conditions suivantes : (1) l'appareil ne doit pas produire de
brouillage, et (2) l'utilisateur de l'appareil doit accepter tout brouillage radioélectrique subi, même si le
brouillage est susceptible d'en compromettre le fonctionnement.

Antennas
FCC (USA) exposure notice
This equipment complies with FCC radiation exposure limits prescribed for an uncontrolled
environment for fixed and mobile use conditions.
This equipment should be installed and operated with a minimum distance of 20 cm between the
radiator and the body of the user or nearby persons. This transmitter must not be co-located or
operating in conjunction with any other antenna or transmitter except in accordance with FCC
procedures and as authorized in the module certification filing.
The gain of the system antenna(s) used for SARA-U201 modules (i.e. the combined transmission line,
mconnector, cable losses and radiating element gain) must not exceed 3.42 dBi (850 MHz) and 1.51
dBi (1900 MHz) for mobile and fixed or mobile operating configurations.
Frequency band gain

Maximum

Band 5 (850 MHz)

3.42 dBi

Band 2 (1900 MHz)

1.51 dBi

ISED (Canada) exposure notice
This equipment complies with radiation exposure limits prescribed for an uncontrolled environment
for fixed and mobile use conditions.
This equipment should be installed and operated with a minimum distance of 20 cm between the
radiator and the body of the user or nearby persons. This transmitter must not be co-located or
operating in conjunction with any other antenna or transmitter except in accordance with ISED
procedures and as authorized in the module certification filing.
The gain of the system antenna(s) used for SARA-U201 modules (i.e. the combined transmission line,
connector, cable losses and radiating element gain) must not exceed 0.61 dBi (850 MHz) and 1.51 dBi
(1900 MHz) for mobile and fixed or mobile operating configurations.

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Regulatory information

FCC Class B digital device notice

Frequency band gain

Maximum

Band 5 (850 MHz)

0.61 dBi

Band 2 (1900 MHz)

1.51 dBi

FCC Class B digital device notice
This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This equipment generates, uses and can
radiate radio frequency energy and, if not installed and used in accordance with the instructions, may
cause harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the equipment off
and on, the user is encouraged to try to correct the interference by one or more of the following
measures:
n Reorient or relocate the receiving antenna.
n

Increase the separation between the equipment and receiver.

Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected.

Consult the dealer or an experienced radio/TV technician for help.

Labeling requirements for the host device
The device shall be properly labeled to identify the product within the host device. The certification
labels of the module shall be clearly visible at all times when installed in the host device, otherwise the
host device must be labeled to display the FCC ID and IC of the module, preceded by the words
"Contains transmitter module", or the word "Contains", or similar wording expressing the same
meaning, as follows:
Contains FCC ID: XPY1CGM5NNN
Contains IC: 8595A-1CGM5NNN
L'appareil hôte doit être étiqueté comme il faut pour permettre l'identification des modules qui s'y
trouvent. L'étiquettes de certification du module donné doit être posée sur l'appareil hôte à un endroit bien
en vue en tout temps. En l'absence d'étiquette, l'appareil hôte doit porter une étiquette donnant le FCC ID et
le IC du module, précédé des mots « Contient un module d'émission », du mot « Contient » ou d'une
formulation similaire exprimant le même sens, comme suit:
Contains FCC ID: XPY1CGM5NNN
Contains IC: 8595A-1CGM5NNN
CAN ICES-3 (B) / NMB-3 (B)
This Class B digital apparatus complies with Canadian ICES-003.
Cet appareil numérique de classe B est conforme à la norme canadienne ICES-003.

Europe (CE)
The XBee Cellular Modem has been tested for use in several European countries. For a complete list,
refer to www.digi.com/resources/certifications.

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Regulatory information

Europe (CE)

If the XBee Cellular Modems is incorporated into a product, the manufacturer must ensure compliance
of the final product with articles 3.1a and 3.1b of the Radio Equipment Directive. A Declaration of
Conformity must be issued for each of these standards and kept on file as described in the Radio
Equipment Directive.
Furthermore, the manufacturer must maintain a copy of the XBee Cellular Modem user guide
documentation and ensure the final product does not exceed the specified power ratings, antenna
specifications, and/or installation requirements as specified in the user guide.

Maximum power and frequency specifications
Maximum power:
n 2 W (33 dBm) Equivalent Isotropically Radiated Power (EIRP) at normal condition.
Supported bands:
n Cellular band 1 2100 MHz UL 1920 to 1980 MHz DL 2110 to 2170 MHz
n

Cellular band 8 900 MHz UL 880 to 915 MHz DL 925 to 960 MHz

Cellular band 19 800 MHz UL 830 to 845 MHz DL 875 to 890 MHz 2 W (33 dBm)

OEM labeling requirements
The “CE” marking must be affixed to a visible location on the OEM product. The following figure shows
CE labeling requirements.

The CE mark shall consist of the initials “CE” taking the following form:
n If the CE marking is reduced or enlarged, the proportions given in the above graduated
drawing must be respected.
n

The CE marking must have a height of at least 5 mm except where this is not possible on
account of the nature of the apparatus.

The CE marking must be affixed visibly, legibly, and indelibly.

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Regulatory information

ACMA (Australia)

Important note
Digi customers assume full responsibility for learning and meeting the required guidelines for each
country in their distribution market. Refer to the radio regulatory agency in the desired countries of
operation for more information.

Declarations of conformity
Digi has issued Declarations of Conformity for the XBee RF Modules concerning emissions, EMC, and
safety. For more information, see www.digi.com/resources/certifications.

ACMA (Australia)
This certification applies to the XBee Cellular Modem.
This module complies with requirements to be used in end products in Australia. All products with EMC
and radio communications must have a registered RCM mark. Registration to use the compliance
mark will only be accepted from Australian manufacturers or importers, or their agent, in Australia. In
order to have an RCM mark on an end product, a company must comply with a or b below:
a. Have a company presence in Australia.
b. Have a company/distributor/agent in Australia that will sponsor the import of the end product.
Contact Digi for questions related to locating a contact in Australia.

RSM (New Zealand)
This certification applies to the XBee Cellular Modem.
This module complies with requirements to be used in end products in New Zealand. All products with
EMC and radio communications must have a registered R-NZ mark. Registration to use the
compliance mark will only be accepted from manufacturers or importers, or their agent, in New
Zealand. In order to have an R-NZ mark on an end product, a company must comply with a or b below:
a. Have a company presence in New Zealand.
b. Have a company/distributor/agent in New Zealand that will sponsor the import of the end
product.
Contact Digi for questions related to locating a contact in New Zealand.

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