Teledesign Systems TS4000C Radio Modem with 3422 Transceiver User Manual Users
Teledesign Systems Inc Radio Modem with 3422 Transceiver Users
Contents
- 1. Users
- 2. General Information
Users
TS4000
Radio Modem
User’s Manual
Version 4.00G
November 1998
2635 North First Street, Suite 205
San Jose, CA 95134-2032
(408) 232-0180
(800) 663-3674
(408) 232-0188 Fax
www.teledesignsystems.com
sales@teledesignsystems.com
support@teledesignsystems.com
corpcomm@teledesignsystems.com
This document is copyrighted by Teledesign Systems Inc. with all rights reserved.
No part of this document may be reproduced in any form without the prior written
consent of Teledesign Systems Inc.
Copyright 1995 - 1998 by Teledesign Systems Inc. All rights reserved.
This manual has been thoroughly reviewed for accuracy, and every effort has
been made to ensure that the information is accurate and complete. However,
different versions of this product have different features and capabilities, and this
manual reflects only one of those versions. Therefore, Teledesign Systems Inc.
assumes no responsibility for errors, omissions or defects in this material, and
shall not be liable for any damages resulting from their use.
The information in this document is subject to change without notice.
TELEDESIGN SYSTEMS INC. MAKES NO WARRANTY OF ANY KIND WITH
RESPECT TO THIS DOCUMENT AND SOFTWARE, EITHER EXPRESSED OR
IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright
Disclaimer
TS4000 Radio Modem User’s Manual Emissions iii
Emissions
The TS4000 has been tested and found to comply with the limits for a Class B
digital device, pursuant to Part15 of the FCC rules (Code of Federal Regulations
47CFR Part 15). Operation is subject to the condition that this device does not
cause harmful interference.
The TS4000 has been type accepted for operation by the FCC in accordance with
Part 90 of the FCC rules (47CFR Part 90). See the label on the unit for the
specific FCC ID and any other certification designations.
The TS4000 has been type accepted for operation by the FCC in accordance with
Part 101 of the FCC rules (47CFR Part 101). See the label on the unit for the
specific FCC ID and any other certification designations.
This Class B digital apparatus meets all requirements of the Canadian
Interference-Causing Equipment Regulations.
The TS4000 has been certified for operation by Industry Canada in accordance
with RSS-119 and RSS-210 of the Industry Canada rules. See the label on the
unit for the specific Industry Canada certification number and any other
certification designations.
Changes or modifications not expressly approved by Teledesign Systems Inc.
could void the user’s authority to operate this equipment.
Shielded cable must be used with this equipment in order to ensure that it meets
the emissions limits for which it was designed. It is the responsibility of the user
to obtain and use good quality shielded cables with this device. Shielded cables
are available from most retail and commercial suppliers of cables designed to
work with radio equipment and personal computer peripherals.
The frequency band from 406.0 to 406.1 MHz is reserved for use by distress
beacons. As such, the TS4000 should not be programmed to transmit on any
frequency within this band. Caution should be used when programming
frequencies into the TS4000 to eliminate the possibility of TS4000 users
interfering with rescue operations on this band.
In order to ensure the safe operation of this radio equipment, the following
practices should be observed.
• DO NOT operate radio equipment near electrical blasting caps or in an
explosive atmosphere.
• DO NOT operate any radio transmitter unless all RF connectors are secure
and any open connectors are properly terminated.
• DO NOT allow the antenna to come close to, or touch, the eyes, face, or any
exposed body parts while the radio is transmitting.
FCC Part 15
Part 90
Part 101
Industry Canada
ICES-003
RSS-119
Notice
406.0 to 406.1 MHz
Operation
Safety Warning
TS4000 Radio Modem User’s Manual Table of Contents iv
Table of Contents
Emissions...................................................................................................... iii
FCC ....................................................................................................iii
Industry Canada .................................................................................iii
Notice...................................................................................................... iii
406.0 to 406.1 MHz Operation............................................................... iii
Safety Warning....................................................................................... iii
Table of Contents......................................................................................... iv
TS4000 Overview........................................................................................... 1
Introduction............................................................................................. 1
Features................................................................................................... 1
Radio Modules ........................................................................................ 2
Frequency Bands ............................................................................... 2
Transmit Power .................................................................................. 2
Channel Spacing and Bandwidth ....................................................... 3
Enclosure................................................................................................. 3
Standard............................................................................................. 3
Watertight........................................................................................... 3
Connections ............................................................................................ 3
Serial Port........................................................................................... 3
Antenna Connector............................................................................. 4
Power Connection .............................................................................. 4
Mounting.................................................................................................. 5
Configuring the TS4000 ......................................................................... 5
Testing the TS4000 ................................................................................. 5
Upgrading the TS4000 Firmware........................................................... 5
Status LEDs............................................................................................. 6
Configuration Program................................................................................. 7
Using Help ............................................................................................... 7
System Requirements ............................................................................ 7
Installation............................................................................................... 7
TS4000 to PC Serial Port Connection ................................................... 7
Programming and Retrieving Configurations...................................... 8
Storing Configurations........................................................................... 8
Diagnostics.............................................................................................. 8
Serial Port..................................................................................................... 10
RS-232 Serial Port Basics .................................................................... 10
Connectors ....................................................................................... 10
DCE vs. DTE .................................................................................... 10
Asynchronous Data .......................................................................... 10
Flow Control ..................................................................................... 10
Serial Port Connector........................................................................... 11
Signal Levels......................................................................................... 11
Signal Options....................................................................................... 11
Configuration Options.......................................................................... 12
Radio Setup.................................................................................................. 16
Configuration Options.......................................................................... 16
Frequency Programming ..................................................................... 18
Channel Switching................................................................................ 19
TS4000 Radio Modem User’s Manual Table of Contents v
AirNet Packet Protocol................................................................................ 21
Overview................................................................................................ 21
Configuration Options.......................................................................... 22
Packet General................................................................................. 22
Packet for Port.................................................................................. 25
Control and Status Strings .................................................................. 28
Control Strings.................................................................................. 28
Status Strings ................................................................................... 29
Master-Slave System Setup................................................................. 29
Setting Packet Timeout .................................................................... 29
Data Packet Transmit Time.............................................................. 30
CSMA System Setup............................................................................. 31
Basic System - Setup Summary....................................................... 31
System with Relays - Setup Summary ............................................. 32
Setting Slot Time .............................................................................. 34
Setting Min Idle Slots........................................................................ 34
Setting Tx Index ............................................................................... 35
Setting Packet Timeout .................................................................... 37
Data Packet Delay............................................................................ 38
Testing.......................................................................................................... 40
AirTest.................................................................................................... 40
Data Test................................................................................................ 40
BER Test................................................................................................ 40
Upgrading Firmware ................................................................................... 42
Upgrading.............................................................................................. 42
Licensing...................................................................................................... 43
User’s License....................................................................................... 43
Channel Spacing and Occupied Bandwidth ..................................... 43
USA (FCC) ....................................................................................... 44
International...................................................................................... 44
Manufacturer’s License........................................................................ 44
USA (FCC) ....................................................................................... 44
Industry Canada ............................................................................... 44
International...................................................................................... 44
Service and Support ................................................................................... 46
Contacting Teledesign ......................................................................... 46
Returning Equipment ........................................................................... 46
Warranty....................................................................................................... 47
Appendix A - Serial Ports............................................................................ 48
Standard Case....................................................................................... 48
Serial Port 1 Pinout........................................................................... 48
Serial Port 2 Pinout........................................................................... 48
Watertight Case..................................................................................... 48
Pinout ............................................................................................... 48
Standard RS-232 Serial Port Pinout.................................................... 50
Standard Usage of the RS-232 Control Signals................................. 50
Signal Levels......................................................................................... 50
Appendix B – ASCII Character Set............................................................. 52
Appendix C - Specifications....................................................................... 53
TS4000 Radio Modem User’s Manual Table of Contents vi
Appendix D - Case Dimensions ................................................................. 54
Appendix E - PCB Component Locations................................................. 55
Appendix F - Internal Jumper Block.......................................................... 56
TS4000 Radio Modem User’s Manual TS4000 Overview 1
TS4000 Overview
The TS4000 Radio Modem is an integrated radio and modem designed for the
wireless transmission of digital data. The TS4000 can transfer data at rates
greater than 19,200 bits per second. The TS4000 includes a synthesized VHF,
UHF or 900 MHz transceiver that can be programmed for up to 99 channels.
This product is ideally suited to OEMs and system integrators who require a
versatile radio modem in a single package. The TS4000 is configured with
windows based PC configuration software.
Main Features
High speed channel rates in excess of 19,200 bits per second.
Selectable operating modes for transparent and packet data operation.
High efficiency switching voltage regulator provides a wide input voltage
range and uses minimum power regardless of the input voltage.
Provides addressed communications for devices that are not directly
addressable themselves.
Includes store-and-forward data repeating for wide area coverage.
Provides two individually configurable data ports.
Supports data activation (three wire) and RTS/CTS handshake protocols.
Includes powerful network diagnostics for non-intrusive monitoring of all radio
and data network functions.
Built-in bit error rate (BER) monitoring.
Configurable RF output power levels.
Programmable receive sensitivity level (squelch) for use on noisy channels.
Watertight case option for outdoor use and marine installations.
Flexible Data Interface
Two highly configurable user data serial ports.
Primary port supports connection to virtually any asynchronous user device.
Secondary port used as diagnostics port, synchronous port, or separately
addressable packet data port.
Full handshake and data activation modes supported on both ports.
Data activation mode requires only receive and transmit data lines for full
communication with user device.
Data rates from 300 to 38,400 baud.
RS-232, RS-485 or TTL signal levels.
Integrated RF Transceiver
Synthesized transceivers cover VHF, UHF and 900 MHz bands.
Programmable RF output power levels.
Channel frequencies are stored in internal flash memory and are selectable
on-the-fly using simple ASCII command strings.
Selectable Channel Protocols
User selectable scrambling codes for private network communications.
Optional Forward Error Correction (FEC) using block coding and interleaving
corrects channel induced errors.
User selectable transparent or AirNet packet data transfer modes.
Introduction
Features
TS4000 Radio Modem User’s Manual TS4000 Overview 2
Integrated AirNet Packet Data Protocol
Allows user directed transmissions to only selected destinations.
Provides addressed communications for devices that are not directly
addressable themselves.
Can be optimized for point to point, point to multi-point, and full mesh
networks.
Supports group and all-call broadcast transmissions.
Built in CSMA/CA algorithm minimizes transmission collisions to maximize
channel efficiency and utilization.
Individual TS4000s can be configured as store-and-forward data repeaters to
extend radio network coverage.
PC Configurable
Windows based configuration software provides quick setup and testing.
Flash memory program storage allows for easy in field firmware upgrades.
Rugged and Reliable
Optional watertight housing and connections designed to withstand abuse
from field and marine use.
External interfaces protected against voltage transients, reverse polarity,
electrical shorts and high VSWR.
Two year no nonsense warranty.
Free technical support provided during all phases of installation and use.
The TS4000 consists internally of two modules; a modem module and a radio
module. The radio module has a number of options depending on the frequency
of operation, transmit power, and channel spacing. It is important that the
TS4000 is ordered with the correct radio module based on the operating
requirements.
The radio module of the TS4000 comes in various frequency bands including
VHF, UHF and 900 MHz. Within each of these bands, there are sub-bands that
define the specific frequency range over which a particular radio module will
operate (i.e. 450 to 470 MHz).
For some of the frequency bands, there several options for the radio module
transmit power. The most common transmit power levels available are 2 watts
and 5 watts. The transmit power can be reduced from the maximum power with
the transmit power level setting control (See Radio Setup).
Transmit Duty Cycle
The transmit power of the radio module effects the maximum transmit duty cycle
that the TS4000 can be operated with. Transmit duty cycle is the percentage of
time that the modem is transmitting (i.e. 50 %). If the TS4000 is operated with
too high a transmit duty cycle, then the radio module may get too hot which can
result in damage. The maximum safe transmit duty can be increased by either
reducing the maximum environmental temperature, adding a heat sink to the
back plate of the TS4000, or reducing the transmit power output with the power
level configuration control.
Power Amplifiers
If more transmit power is desired than the internal TS4000 radio module can
provide then an external power amplifier can be used to boost the power. For
connection to the TS4000 it is important that the power amplifier have automatic
power sensing to switch between receive and transmit modes. It is also
important that the power amplifier has fast power switching so that the TS4000
Radio Modules
Frequency Bands
Transmit Power
TS4000 Radio Modem User’s Manual TS4000 Overview 3
transmit attack time (amount of time to initiate a transmission) does not have to
increased excessively.
For some frequency bands, there are multiple options for the radio module
channel spacing and bandwidth.
Channel Spacing
The channel spacing defines how close together the channels are within a band
(i.e. 12.5 kHz). To use channels with a certain channel spacing, the radio
module’s frequency synthesizer must be programmable to multiples or sub-
multiples of the channel spacing. The TS4000 radio module should be ordered
based on the channel spacing of the channels to be used.
Channel Bandwidth
The channel bandwidth is the amount of frequency spectrum that the radio
transmit signal is allowed to occupy (i.e. 16 kHz). This bandwidth must be
controlled in order to minimize the interference between users on adjacent
channels.
Transmit Channel Bandwidth
For the TS4000, the data rate and the type of modulation control the transmitted
channel bandwidth. Therefore, it is important that the TS4000 is setup so that its
transmitted bandwidth is less than that prescribed for the channels being used
(See Radio Setup, Licensing).
Receive Channel Bandwidth
The receive filters of the TS4000 radio module are designed for a specific
channel bandwidth. The radio module should be ordered with a receive filter
bandwidth that matches the bandwidth of the channels used.
Note that if multiple channel bandwidths are to be used, then the radio module
should be ordered for the channel with the highest channel bandwidth. This may
result in less than optimal performance on channels with narrower channel
bandwidths.
The TS4000 is available in either a standard or watertight enclosure (see
Appendix D - Case Dimensions).
The standard enclosure has four external connectors; an antenna connector, a
power connector and two serial port connectors.
The watertight enclosure is environmentally sealed and is designed to withstand
dust, rain and water splashes.
Caution: The watertight enclosure should not be submerged in water.
The watertight enclosure has two external connectors; an antenna connector and
an interface connector that provides the serial port and power connections. The
interface connector is a 19 pin LEMO connector. The mating connector for this is
a LEMO FGG.2B.319 series connector.
The TS4000 has two serial ports that provide a data connection between the
TS4000 and the host equipment. The serial ports are standard RS-232
Channel Spacing and
Bandwidth
Enclosure
Standard
Watertight
Connections
Serial Port
TS4000 Radio Modem User’s Manual TS4000 Overview 4
asynchronous serial interfaces and are setup as DCEs. The serial ports provide
all the standard RS-232 handshake lines. In addition, the TS4000 provides a
number of configuration options that allow the serial port line usage to be
customized for different host equipment (see Serial Port Configuration Options).
Signal Levels
Serial port 1 can be configured for either RS-232 or TTL signal levels. To change
the signal level setting, the modem must be opened and the four jumper plugs
next to the serial port connector moved to the desired position (See Appendix A -
Serial Port, Appendix E - PCB Component Locations, Appendix F - Internal
Jumper Block).
Standard Case
The serial port connectors are standard 9 pin subminiature D with female pins.
These ports can be mated to with standard PC serial cables. To minimize
emissions and interference, the serial cables used should be good quality
shielded cable (See Appendix A - Serial Port).
Watertight Case
The watertight case provides the serial port connections through a single sealed
interface connector (See Appendix A - Serial Port).
A variety of antennas can be used with the TS4000, but it is important that the
antenna provides a 50 ohm load at the radio’s operational frequencies. In
addition, all cabling used with the antenna must be good quality coaxial cable with
a 50 ohm characteristic impedance.
Caution: The modem should never be allowed to transmit without an
antenna or dummy load attached to the antenna connector.
Standard Case
The standard case comes with a 50 ohm female BNC antenna connector.
Watertight Case
The watertight case comes with a 50 ohm female TNC antenna connector.
The TS4000 requires a DC supply voltage between 9 and 28 volts. Note that the
minimum supply voltage depends on the particular radio module in the TS4000.
In addition, the power (watts) used by the TS4000 also depends on the particular
radio module.
Switching Voltage Regulator
Internally, the TS4000 has a high efficiency switching voltage regulator (as
opposed to a linear voltage regulator). The switching regulator minimizes the
amount of power that the TS4000 requires. Also, the power required (watts) is
independent of the input supply voltage.
Power Supply Current
The power supply current required depends on the input voltage used. This can
be calculated with the following formula.
Max Power Supply Current (amps) = Max Power (watts) / Input Voltage
Antenna Connector
Power Connection
TS4000 Radio Modem User’s Manual TS4000 Overview 5
Max Power = 10 watts (The actual value depends on the particular radio module
in the TS4000).
Power Supply Voltage = 20 volts
Max Power Supply Current = 10 / 20 = 0.5 amps
Standard Case
With the standard case power can be connected through either the power
connector or one of the serial port connectors. The power connector is a 2 pin
Molex Micro-Fit 3.0 (Molex P/N 43045-0202) with pin 1 as ground and pin 2 as
power. The mating plug for this connector is a Molex P/N 43025-0200. See the
Serial Port section for details on connecting power through the serial ports.
Watertight Case
With the watertight case power is connected through the sealed interface
connector.
Fuses
The TS4000 has an internal 4 amp fuse for each of the three possible power
connections (See Appendix E - PCB Component Locations). The power source
used with the TS4000 should also be fused with an in-line power fuse.
The preferred method of mounting the TS4000 is to use the mounting bracket
supplied with the modem. An alternative is to use the threaded mounting holes in
the bottom of the TS4000 (see Appendix D - Case Dimensions).
The TS4000 is supplied with a windows based PC configuration program.
Configuring the TS4000 consists of configuring the modem operating parameters
and also configuring the frequency channels. For details on how to load and start
the configuration program see Installation in the TS4000 Configuration Program
section.
Making selections with the controls on the various configuration screens sets a
configuration. Once set, configurations can be programmed into the TS4000. In
addition, configurations can be retrieved from the TS4000. Configurations can
also be stored and recalled as PC files. Details about the configuration controls
are available later in this manual and in the on line help of the configuration
program.
Teledesign provides general-purpose wireless modem test software called
AirTest. AirTest can send data and gather performance statistics, including BER
(Bit Error Rate), about the link between two modems. AirTest can be started with
the AirTest button on the main screen of the configuration program (See Testing).
The TS4000 comes with flash program memory that allows the firmware to be
easily upgraded in the field. Firmware is upgraded with the upgrade program
which is included as part of the TS4000 configuration program. The upgrade
program is started with the Upgrade Firmware button on the main screen of the
configuration program (See Upgrading Firmware).
Example:
Mounting
Configuring the
TS4000
Testing the TS4000
Upgrading the
TS4000 Firmware
TS4000 Radio Modem User’s Manual TS4000 Overview 6
The TS4000 has three LED indicators to provide operational status of transmit
(TX), receive (RX) and power (PWR) functions. Special combinations of these
indicators are used to indicate secondary operating modes and fault conditions.
TS4000 State LEDs Indicator State
Normal Operation PWR
RX
TX
On when the TS4000 is powered.
On when the TS4000 detects activity on the
radio channel.
On when the TS4000 is transmitting.
Program Mode RX, TX Both on continuously.
Reset RX, TX Flash together four times.
Although the reset indication takes about
four seconds to complete, the TS4000 is
fully operational when the flashing
begins.
Transmit Test Mode TX Flashes for the duration of the test.
Invalid Frequency
Channel Fault RX, TX Alternately flash.
This fault occurs if the TS4000 is set for
a channel that does not have a valid
frequency programmed.
Transmit Buffer
Overflow TX Flashes ten times for each occurrence.
Receive Buffer
Overflow RX Flashes ten times for each occurrence.
Diagnostics Fault PWR Flashes for the duration of the fault.
In this mode the TS4000 has detected a
fault but continues to operate. Operation
may be unreliable due to the fault.
The most common cause of this state is an
out of range power source. The source of
the fault can be diagnosed with the
configuration program (see TS4000
Configuration Program, Diagnostics).
Catastrophic Fault RX, TX Alternately flash until the fault is cleared and
the TS4000 is reset.
In this mode the TS4000 has detected a
catastrophic fault and is non-operational
until the fault is corrected.
The source of the fault can be diagnosed
with the configuration program (see TS4000
Configuration Program, Diagnostics).
Status LEDs
TS4000 Radio Modem User’s Manual Configuration Program 7
Configuration Program
The configuration program is used to configure the TS4000 for operation.
Configuring the TS4000 consists of independently configuring both the modem
operation and the radio frequency channels. The configuration program consists
of controls and menus. The controls set the configuration and test options. The
menus (line items at the top of the screen) execute program commands.
In addition to configuring the TS4000, the configuration program provides access
to the AirTest wireless modem test software and the TS4000 firmware upgrade
program (see Testing, Upgrading Firmware).
The configuration program has on-line help that contains information on how to
use the program and also detailed information on specific controls and menus.
Help is accessed by selecting a command from the help menu, pressing the
question button or pressing the F1 key.
Personal computer using a 486 or higher microprocessor (Pentium
recommended).
Microsoft Windows 3.1, Windows 95 or Windows NT 3.51 or later.
4 MB of RAM (16 MB recommended).
4 MB of available hard-disk space.
High-density (1.44 MB) 3.5” disk drive.
1) Put the first installation disk into the PC.
2) Run the installation program (Install.exe).
3) Follow the installation program instructions.
Serial Cable
To transfer configurations between the TS4000 and a PC, their serial ports must
be connected together. The serial cable used should be a standard straight
through (i.e. pin 1 to pin 1, pin 2 to pin 2, etc) serial cable. This is the same type
of cable used to connect a PC to a standard phone modem (See Serial Port).
Software Connection
Before configurations can be retrieved from and programmed into the TS4000 the
configuration program must connect to the TS4000. To connect, select the
Connect to Modem command from the Modem
menu or press the Connect to Modem button.
Connecting to the TS4000 puts it into program
mode. When in program mode the TS4000's RX
and TX LEDs remain on continuously.
When connected to the TS4000 the configuration
program may disable (lighter shade) some of the
controls. These disabled controls are options
that are not available with that particular TS4000's version of firmware. These
controls are re-enabled when the connection is broken (using the Disconnect
command from the Modem menu or the Disconnect button).
Using Help
System
Requirements
Installation
TS4000 to PC
Serial Port
Connection
TS4000 Radio Modem User’s Manual Configuration Program 8
The configuration of the TS4000 can be read out of the modem by selecting the
Retrieve Configuration command from the Modem menu or by pressing the
Retrieve Configuration button.
To program a configuration into the TS4000, use
the Program Configuration command from the
Modem menu or the Program Configuration
button.
CAUTION: Programming a configuration into the TS4000 will write over
(destroy) the configuration currently in the TS4000. To avoid losing the
TS4000’s configuration information, save the configuration by retrieving it and
then saving it as a PC file.
Configurations can be stored and recalled as PC files.
This is done using the commands under the File menu or
the corresponding buttons.
Command Action
New-Default Create a new file with default values.
Open Open a previously stored file. The user is prompted with a
directory and file list.
Close Close the active file.
Save Save the active file under the current name.
Save As Save the active file under a different name or in a different
directory. The user is prompted with a directory and file list.
Recent File List This shows the last ten open files. A file can be recalled by
selecting its name from the list.
The configuration program can access diagnostics
information from the TS4000. This is done using
commands under the Modem menu or the
corresponding buttons.
Programming and
Retrieving
Configurations
Storing
Configurations
Diagnostics
TS4000 Radio Modem User’s Manual Configuration Program 9
Command Action
Diagnostics Run, read and display diagnostic status of the
TS4000. The diagnostics tests the major
components of the modem and also monitors the
power supply voltages.
Retrieve Hardware
Configuration Read and display the hardware configuration. This
includes details on the firmware version and
memory configuration.
Retrieve Radio
Configuration Read and display the radio configuration. This
includes details about the radio’s frequency,
channel spacing and transmit power.
TS4000 Radio Modem User’s Manual Serial Port 10
Serial Port
The serial port provides an asynchronous data connection between the TS4000
and the host equipment. The TS4000 serial port is a standard RS-232 serial port
with a number of options to allow connection to a wide variety of serial host
equipment.
The EIA (Electronic Industries Association) RS-232C standard is a standard for
short distance (less than 50 feet) serial communications. The standard defines
the electrical signal levels, interface characteristics and the operation of the
control signals (handshake lines). Although the standard defines the operation of
the handshake lines, there is significant variation in the way these signals are
used by different equipment.
The RS-232 standard does not require the use of a specific connector. However,
most asynchronous RS-232 serial ports use either a 9 pin or 25 pin subminiature
D connector. The same signals are provided with both connectors, but of course
the pinouts are different (see Appendix A - Serial Port).
RS-232 serial ports come in two varieties; DCE (Data Communication
Equipment) and DTE (Data Terminal Equipment). This defines the direction of
the serial port’s lines (driven or received). It also typically defines the polarity of
the connector. DCEs typically use female pin connectors and DTEs typically use
male pin connectors.
Connecting a DCE port to a DTE is the most common setup and requires a
standard straight through cable (i.e. pin 1 to pin 1, pin 2 to pin 2, etc.). When
connecting two DCEs or two DTEs together a null modem cable is required. The
purpose of a null modem cable is to cross connect the appropriate signals.
However, null modem cables are not all the same and therefore it is important to
verify that a specific cable is appropriate for a specific application.
The TS4000 is designed to work with asynchronous serial ports. Asynchronous
ports do not use clocks or timing signals to synchronize data transfers. Instead
data is framed into asynchronous characters which the ports synchronize to.
An asynchronous character consists of a start bit, data bits and stop bits. The
start bit indicates the beginning of a character. The number of data bits varies,
but is typically between 7 and 9 bits. The data bits sometimes include a parity bit
that provides error check information with each character. The number of stop
bits also varies but is typically 1 or 2 bits.
Flow control is the method for controlling the flow of data between the DCE and
DTE. Flow control is used to prevent the DTE and DCE data receive buffers from
overflowing. There are several different methods used for flow control and as
with everything related to RS-232 there is no one standard. The two main
variations of flow control are hardware flow control that utilizes the RS-232
handshake lines and software flow control that utilizes characters sent along with
the normal data.
Hardware Flow Control
Hardware flow control typically uses two control lines, one for each direction of
data. When a port activates its flow control signal it is indicating its readiness to
receive data. Deactivating the flow control signal indicates that the port can no
longer receive data because its buffer is full or close to full.
RS-232 Serial Port
Basics
Connectors
DCE vs. DTE
Asynchronous Data
Flow Control
TS4000 Radio Modem User’s Manual Serial Port 11
The most common form of hardware flow control, and the one used by most full
duplex wired (as opposed to wireless) modems, is RTS/CTS. With RTS/CTS
flow control, RTS provides flow control for the DTE and CTS provides flow control
for the DCE. One problem with RTS/CTS flow control is that for many half duplex
modems (most wireless modems) the RTS signal is used to frame transmit data
going from the DTE to the DCE. This use of RTS conflicts with using RTS for
flow control of data to the DTE.
An alternative form of hardware flow control is DTR/DSR. With DTR/DSR flow
control, DTR provides the flow control for the DTE and DSR provides the flow
control for the DCE.
Software Flow Control
Software flow control uses characters sent over the data lines to control data flow.
These characters are sent along with the normal flow of data between the DTE
and DCE. There is typically one character that is used to stop the flow of data
and a different character to restart data flow. Software flow control can use any
characters to start and stop flow. However the most common characters used
are the ASCII XON (starts flow) and XOFF (stops flow) characters. Because
these are the most common characters used, software flow control is often
referred to as XON/XOFF flow control. The ASCII XON character is the decimal
character 17 (0x11 hex) and is also known as DC1 or Ctrl-Q. The ASCII XOFF
character is the decimal character 19 (0x13 hex) and is also known as DC3 or
Ctrl-S (See Appendix B - ASCII Character Set).
A problem with software flow control is that the normal data passed over the
communications link cannot include the flow control characters. If it does, the
flow of data will be incorrectly stopped or started. This limits the characters that
can be used by the host application and also prevents the sending of binary (all
character numbers) data.
The TS4000 serial ports are setup as DCEs (Data Communication Equipment).
The TS4000 with the standard case uses two 9 pin subminiature D connectors
with female pins for the serial ports. The TS4000 with the watertight case uses a
19 pin environmentally sealed LEMO connector (see Appendix A - Serial Port).
Serial port 1 can be configured for either RS-232 or TTL signal levels. To change
the signal levels, the modem must be opened and the four jumper plugs next to
the serial port connector set to the desired position (see Appendix A - Serial Port,
Appendix F - Internal Jumper Block).
Serial port 2 is always set for RS-232 signal levels.
The serial ports can be setup to provide different internal electrical connections to
the DTR, DSR and RI pins. To change the pin connections, the modem must be
opened and the jumper plugs next to the serial port connector set to the desired
position (see Appendix F - Internal Jumper Block).
The RI (Ring Indicator) pin is pin 9 of a standard 9 pin subminiature D connector
and is an output for DCEs (the TS4000). The TS4000 has no internal RI signal
and therefore the RI pin is normally left unconnected.
Alternate Connection: RI for Modem Power
As an alternative, the DTR pin can be connected as a power pin into the TS4000.
This is non-standard use of this pin and therefore care should be taken when
Serial Port
Connector
Signal Levels
Signal Options
RI Pin Signal Options
TS4000 Radio Modem User’s Manual Serial Port 12
connecting the TS4000 to other serial devices. For most serial devices this is not
a problem because RI is a modem (DCE) output and the TS4000 power supply
mostly falls within the allowed voltage range for RS-232 signals. Therefore the
power voltage on this pin is interpreted as an active RI signal. For systems that
use the RI signal differently, or cannot operate with power on this pin, this pin
should be disconnected between the TS4000 and the host equipment.
Alternate Connection: RI Connected to DSR
As an alternative, the RI pin can be connected to the internal DSR output signal.
The DSR (Data Set Ready) pin is pin 6 of a standard 9 pin subminiature D
connector and is an output for DCEs (the TS4000). For the TS4000, the DSR pin
is normally connected to the internal DSR output signal.
Alternate Connection: DSR Always High
As an alternative, the DSR pin can be set to always be in the active high state. In
this case it is internally connected to +5 volts through a 1 K ohm resistor.
The DTR (Data Terminal Ready) pin is pin 4 of a standard 9 pin subminiature D
connector and is an input for DCEs (the TS4000). For the TS4000, the DTR pin
is normally connected to the internal DTR input signal.
Alternate Connection: DTR for Modem Power
As an alternative, the DTR pin can be connected as a power pin into the TS4000.
Caution: The use of the DTR pin for power is non-standard. Therefore the
TS4000 serial port must not be connected to a standard serial device that
drives the DTR pin (i.e. a PC). This results in the power supply voltage of the
TS4000 being shorted to the DTR output of the host serial port, which could
damage to the host device. Therefore, when connecting the TS4000 to a PC for
configuration, make sure that the cable does not have a DTR (pin 4) connection.
The serial port provides a number of configuration options that allows it to be
connected to virtually any asynchronous host equipment. These configuration
options are set using the Serial Port tab of the Modem Configuration.
DSR Pin Signal Options
DTR Pin Signal Options
Configuration
Options
TS4000 Radio Modem User’s Manual Serial Port 13
The baud rate list provides selection of the serial port asynchronous baud rate.
The available selections are 1200, 2400, 4800, 9600, 19200 and 38400 baud.
These options set the number of data bits in each asynchronous character.
These options set the parity of the asynchronous characters.
Selection Description
Hardware Handshake In this mode the RTS handshake line is used to
frame transmit data into bursts. The TS4000 begins
transmission when RTS is activated and at least
one character (non-control string) is received.
Transmission ends when RTS goes inactive and
the burst has been completely transmitted.
Data Activation This mode uses a character timer to frame the
transmit data into bursts. The TS4000 begins
transmission when one character (non-control
string) is received. The transmit burst is completed
when the transmit data line is idle (no data) for the
number of character periods defined by the data
activation timeout control.
Data Activation Timeout
(Timeout Time) This control sets the number of character periods of
idle required on the serial port's transmit data line to
declare the end of a transmit burst.
Char Period = Char Length / Baud Rate
Where: Char Length = Data Bits + Parity + 2
Data Bits is the value selected from the Data Bits
control. Parity is 0 if none is selected from the
Parity control and 1 if even or odd is selected. The
2 added to the accounts for the start and stop bits
of an asynchronous character. Baud Rate is the
value selected from the baud rate list.
Baud Rate List
Data Bits
Parity
Protocol Options
TS4000 Radio Modem User’s Manual Serial Port 14
This option only has effect if packet operation is not enabled.
Selection Description
Disabled The modem begins transmitting as soon as it
receives the first non-control character of a transmit
burst.
Enabled The modem waits for a complete transmit burst
before it begins transmitting.
Selection Description
Idle Time Between Bursts This sets the minimum amount of time (in character
periods) that the receive data (RXD) line will be idle
(inactive) between received bursts of data. If this
value is set to zero, the receive data line may
remain active continuously when multiple bursts of
receive data are transferred to the host.
If the DCD line option is set for the Active when
Sending Receive Data to the User then the DCD
line will also be inactive during the receive data line
idle times.
DTR Enabled for Receive
Data Flow Control When enabled, DTR acts as flow control for receive
data coming from the TS4000 to the host. When
DTR is inactive, data received by the TS4000 is
stored in an internal buffer and inhibited from being
sent to the host equipment. The flow of receive
data out of the serial port resumes when DTR is
activated.
Selection Description
Active when Sending
Receive Data to the User DCD is active when receive data is sent out of the
TS4000 via the serial port.
Active when Receiving DCD is active when the TS4000 detects a signal on
the radio channel. This mode can be used to
remote the receive LED.
Both DCD is active when either receive data is being
sent out the serial port or when a signal is detected
on the radio channel. Note that for most conditions
and configurations these states overlap.
Wait For Complete Burst
Before Beginning
Transmission
Receive Data Protocol
DCD Line Control
TS4000 Radio Modem User’s Manual Serial Port 15
Selection Description
Always Active The CTS line is active.
Active when Transmitter is
Sending Data CTS is normally inactive and is activated when the
TS4000 is transmitting and the radio channel is
ready for the transmission of data.
Active when Transmitting CTS is normally inactive and is activated when the
TS4000 is transmitting. Note that the modem
begins transmitting only after it has received at
least one character (non-control string) of data.
This selection can be used to remote the transmit
LED.
Delayed RTS CTS is normally inactive and is activated a fixed
time after RTS becomes active. The time is
controlled with the RTS to CTS delay value.
Deactivate when Transmit
Buffer is Full When this is enabled, CTS is deactivated when the
transmit buffer is full. This setting effects all of the
above options.
Selection Description
Active when Operational DSR is active when the TS4000 is powered and
has passed self test.
Active when Transmitting DSR is active when the TS4000 is transmitting.
This selection can be used to remote the transmit
LED.
Active when Receiving DSR is active when the TS4000 detects a signal on
the radio channel. This mode can be used to
remote the receive LED.
CTS Line Control
DSR Line Control
TS4000 Radio Modem User’s Manual Radio Setup 16
Radio Setup
The radio setup requires setting the modem configuration options and also setting
the radio frequencies. The modem configuration options are accessed on the
Radio tab of the Modem Configuration. The frequency programming is accessed
with the Frequency Configuration button on the main screen of the configuration
program.
The radio configuration options set the operation of the radio. These
configuration options are set using the Radio tab of the Modem Configuration
portion of the configuration program.
Selection Description
Occupied
Bandwidth The occupied bandwidth sets the amount of frequency
bandwidth that the transmitted signal will use. A higher value
corresponds to more bandwidth and therefore provides better
BER (Bit Error Rate) performance.
The occupied bandwidth should be set to equal to or lower
than the occupied bandwidth that is allowed for the channels
in use.
Example: The FCC licenses many channels with a 12.5 kHz
channel spacing for an 11K2 (11.2 kHz) emission designator.
Therefore the occupied bandwidth must be set for 11.2 kHz or
lower.
The maximum value that occupied bandwidth can be set for is
dependent on the specific radio module ordered with the unit.
This is set at the factory when the unit is manufactured. This
maximum value will be shown in the range label when the
configuration program is connected to the modem.
4 Level FSK Four level FSK modulation.
This is the most spectrally efficient modulation. Therefore,
this modulation allows the highest data rate for a given
occupied bandwidth. However, it also requires the highest
receive signal level to achieve a given BER (Bit Error Rate).
Configuration
Options
Modulation
TS4000 Radio Modem User’s Manual Radio Setup 17
Selection Description
GMSK (BT=0.3) Gaussian Minimum Shifted Keyed modulation with a BT = 0.3.
This is the less spectrally efficient than 4 Level FSK
modulation and more spectrally efficient than GSMK (BT=0.5)
modulation.
GMSK (BT=0.5) Gaussian Minimum Shifted Keyed modulation with a BT = 0.5.
This is the least spectrally efficient modulation. However, it
provides the best BER for a given receive signal level.
Rate The over the air modulation bit rate.
All TS4000s that communicate together must use the same
setting. Lower settings result in better signal demodulation
which results in a better (lower) BER (Bit Error Rate) for a
given receive signal level.
The maximum rate that can be set depends on the settings of
occupied bandwidth and modulation type
Selection Description
Active Channel
at Power Down The channel activated at power up is the channel that was
active when the modem was last powered down.
Fixed Channel The channel activated at power up is the channel set in the
corresponding control.
This sets the receive signal level at which the receiver is activated. This is similar
to the squelch control on mobile radios. Normally this level is set slightly lower
than the level at which the TS4000 can correctly demodulate the incoming data.
When using the TS4000 in a high noise environment, this level can be raised so
that the TS4000 is more selective about the signals that it attempts to
demodulate. This is important for configurations that do not allow the TS4000 to
transmit while it is receiving. These include configurations with packet operation
enabled or with the Force Transmit over Receive control disabled.
This control has effect only if packet operation is disabled.
Selection Description
Disabled The modem will not transmit while receiving. Transmit data is
buffered and then transmitted when the TS4000 stops
receiving.
Enabled The modem transmits as soon as data is ready without regard
to the receive state.
When enabled, the timeout timer stops the TS4000 from transmitting after the
specified period of continuous transmission. This is used to avoid locking up the
radio channel due to a continuous transmission caused by an equipment fault.
This sets the transmit power level. The maximum transmit power that can be set
depends on the specific radio module in the TS4000. Therefore the maximum
value that can be set is listed only when the configuration program is connected
to the TS4000.
This is additional attack time added to the radio transmission process. This is
used in setups where the TS4000 is used with a power amplifier or repeater
system that creates an extra delay in establishing the radio channel.
Frequency Channel at
Power Up
Receive Carrier Detect
Level
Force Transmit Over
Receive
Transmit Timeout Timer
Transmit Power
Additional Transmit Attack
Time
TS4000 Radio Modem User’s Manual Radio Setup 18
Attack time is the amount of time necessary to establish the radio channel. This
includes the power up time for the transmitter and the time for the receiver to
sense and demodulate the transmit signal. The TS4000 is preset for the
appropriate attack time of the installed radio module. Therefore, this control
should normally be set to zero.
Selection Description
Disabled This minimizes the amount of overhead required to send data.
Enabled Transmit data is block coded (12,8 Hamming) and interleaved
(16 bits). This provides error correction for strings of errors
up to 16 bits long. Coding requires an extra 50 % overhead
on top of formatted data. This type of coding is ideal for
combating errors induced from multi-path fading common in
mobile environments.
The scramble code determines the pseudo-random sequence used to scramble
the transmitted data. This provides data privacy and also randomizes the data for
optimum signal detection. All TS4000s operating in the same network must use
the same scrambling code.
The TS4000 comes in various frequency bands (i.e. 450 to 470 MHz) and can be
programmed for any valid channel within a given frequency band. The TS4000
can be set for up to 99 frequency pairs. A frequency pair is a receive frequency
and a transmit frequency which can be set to the same or different frequencies.
Frequency channels are programmed into the TS4000 using the configuration
program. To access the frequency program screen press the Frequency
Configuration button on the main screen of the configuration program. Frequency
channel configuration settings are programmed into and retrieved from the
TS4000 the same as the modem configuration settings.
The FCC rules state that only authorized service/maintenance personnel should
be allowed to change the frequencies programmed into radio devices. Because
of this, a software enable code is required to enable the frequency programming
capability of the TS4000 configuration program. Note that this enable code is not
required to retrieve and display the channel frequencies programmed in the
TS4000.
Please contact Teledesign Systems for information on finding the nearest
authorized service center.
Enable Coding
Data Scramble Code
Frequency
Programming
TS4000 Radio Modem User’s Manual Radio Setup 19
The minimum and maximum frequencies and the channel spacing depend on the
specific radio module in the TS4000. The configuration program does not know
this information unless it is connected to the TS4000. Therefore, these fields in
the Radio Settings frame only show up when the configuration program is
connected to the TS4000. When the user creates a new frequency configuration
file these values can be set in the channel frequencies frame. This allows the
user to create, modify and store frequency files without being connected to a
TS4000. When a file is used to program frequency channels into the TS4000,
the configuration program compares the radio values with the file values and
determines if they are compatible. If they are compatible then the programming
continues. If they are not compatible then the user is prompted to make the
necessary changes in these values so that only valid frequency channels are
programmed into the TS4000.
During normal operation, the frequency channel can be switched on the fly. The
channel is switched by transferring the following ASCII character string to the
TS4000’s serial port.
+TSCxx Where: xx = Channel number from 01 to 99
Note: The letter characters must be upper case.
The channel change control string is sent to the modem the same as standard
transmit data. For the control string to be recognized it must be the first
characters of a burst of transmit data. If the control string is sent alone (no data
following), then the TS4000 will switch to the receive frequency of the new
channel pair and wait in receive mode. If the control string is sent with a transmit
data burst following it, then the TS4000 will switch to the transmit frequency of the
new channel pair and transmit the burst.
The active channel can be determined with the channel query string. This is done
with the following ASCII character string.
Radio vs. File Settings
Channel Switching
Determining the Active
Channel
TS4000 Radio Modem User’s Manual Radio Setup 20
+TSC? Note: The letter characters must be upper case.
The response string is sent out the serial port and is as follows.
+TSCxx Where: xx = Channel number from 01 to 99
If a frequency channel is selected that has not been programmed with valid
frequencies, the modem will not receive or transmit and the RX and TX LEDs will
alternately flash.
The channel that the TS4000 activates at power up depends on the setting of the
Frequency Channel at Power Up control.
Invalid Channel Selection
Channel at Power Up
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 21
AirNet Packet Protocol
AirNet is an embedded packet protocol available in some Teledesign Systems
modems. AirNet provides a complete protocol that manages the end to end data
transfers of wireless networks. The AirNet protocol is flexible and configurable so
that it can be used with any host (user) system or network architecture.
The basic purpose of the AirNet packet protocol is to ensure that data is reliably
transferred between nodes in the network. This means preventing data from
being lost, repeated or corrupted at the receiving nodes. This is accomplished by
combining transmit data into packets which contain user data and control
information. The control information includes addressing, sequencing and error
detection. Addressing information allows receiving nodes to determine if a packet
is intended for them and also who the source of the packet was. Sequence
information is used so that the data can be reconstructed in the correct order, and
so that repeated packets of the same data are not given to the user. Error
detection is provided by adding a CRC (Cyclic Redundancy Check) onto the
packet so that any corruption of the packet can be detected.
The key feature of any packet data protocol is its ability to identify and coordinate
data transfers between individual nodes in a network. In order to move data
between nodes, each node is assigned a unique address. With the AirNet
protocol each node is assigned a unique individual and group address. Group
addresses allow the nodes in a network to be partitioned into classes of service or
segmented into regions. The AirNet protocol allows a data packet to be
transferred to an individual node, to all nodes in a group (group broadcast), or to
all nodes in all groups (network broadcast).
The AirNet protocol also includes multicast reception. Multicast reception is the
ability of a node to receive group broadcasts for groups other than its own. This
allows a node to be a member of a number of different groups at the same time.
Individual node to node data transfers can be sent with or without positive
acknowledgment from the destination node. Positive acknowledgment is the
process where a destination node which receives an error free packet sends a
return packet (without user data) to tell the source node that the packet was
received correctly. This allows the source node to be sure that the data has been
transferred. If the sending node does not receive an acknowledgment (ACK)
packet within a preset period of time then it automatically re-sends (or retries) the
data packet.
Note that broadcast packets are never acknowledged and therefore the source
node cannot be sure that they have been received correctly by all the destination
nodes.
For most wireless data networks, there is the possibility that more than one node
will attempt to transmit simultaneously. This is termed a collision and typically
results in the data from both nodes being lost. To minimize collisions, the nodes
must have an orderly means of accessing the shared channel. The AirNet
protocol uses a CSMA/CA (Carrier Sense Multiple Access with Collision
Avoidance) protocol to coordinate channel access (see CSMA System for
details).
In many networks some nodes are unable to directly communicate with all other
nodes in the system due to insufficient RF coverage. To combat this many
systems use frequency translating repeaters that are located at advantaged
(mountaintop) locations. In some situations, the use of a repeater may be
Overview
Packet Basics
Addressability
Acknowledgment and
Retries
Channel Access
Store and Forward Relay
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 22
logistically difficult and may not completely solve all propagation problems. The
AirNet protocol provides an option where nodes can be set up as store and
forward relays. The relay nodes store packets that they receive and repeat
(forward) the packets when the channel is idle. The relay nodes can be set to
relay all packets or only packets with certain source or destination addresses.
Complete Packet Capability
Nodes automatically re-send packets which are not received correctly.
Robust 32 bit CRC ensures that packets are received correctly.
Adjustable maximum number of retries.
Adjustable maximum packet size - Large packets can be automatically
broken up into smaller packets for reliable transmission.
Easy to Use Host Control and Status
The host (user equipment) controls operation of the packet protocol with
simple ASCII command strings.
No special formatting of user data is required.
Status strings can be enabled to provide information on the success or failure
of packet transmissions.
Addressing
Individual addresses from 1 to 999.
Group addresses from 1 to 60.
Various transfer types
Individual (point to point with acknowledge) - The acknowledgment
provides for guaranteed delivery of the data packets.
Individual without acknowledgment.
Group broadcast - Unacknowledged transfer to all members of a group.
Network broadcast - Unacknowledged transfer to all modems.
Multicast receptions - Allows a modem to receive group broadcasts to groups
other than its own. This can be used to create sub-groups or super-groups of
modems.
Channel Access
CSMA/CA - Carrier Sense Multiple Access with Collision Avoidance.
Adjustable Transmission Index (transmit probability) - Allows a network to be
optimized for maximum efficiency.
Adjustable Slot Time - Allows the modem to be optimized for different radios
and repeater systems.
Store and Forward Data Repeater
Any unit can be configured as a relay node. Allows for easy expansion of the
network.
Relay filter allows for relaying of only packets to or from select nodes. This
minimizes the amount of relay traffic created.
These configuration options are set using the Packet General tab of the Modem
Configuration.
Features
Configuration
Options
Packet General
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 23
Selection Description
Enable Packet
Operation This activates packet operation for all user data.
The type of Medium Access Control (MAC) determines how a modem decides
when to transmit packets. This effects the transmission of both data and
acknowledgment packets.
Selection Description
Master-Slave The modem will transmit data as soon as the channel
becomes idle. This mode should only be used for master-
slave systems where two modems will never attempt to
transmit at the same time. This also implies that store and
forward relays are not used in the system.
CSMA Carrier Sense Multiple Access. This mode should be
selected for systems where multiple modems may attempt
to transmit simultaneously. With this setting, the modem
waits until the channel becomes idle and then transmits in
each following idle slot based on a random probability of
transmission (see CSMA MAC Options - Transmission
Index). This minimizes the potential for collisions in multi-
access systems.
Packet Activate
Medium (Channel) Access
Control (MAC)
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 24
Control Description
Slot Time This sets the transmit slot time (see Setting Slot Time).
Min Idle Slots This sets the minimum number of idle slots before a
modem attempts transmission (see Setting Min Idle Slots).
If the minimum number of idle slots is set to zero the
modem randomizes its transmission attempts with the first
slot after the channel becomes idle. For values greater
than zero, the modem waits that many slots before
randomizing its transmission attempts.
Tx Index The transmission index (TI) is the inverse of the probability
of transmitting in an idle slot. An index of 4 corresponds to
a 1/4 or 25% chance of transmitting in an idle slot. The goal
of setting TI is to maximize efficiency on the channel. If TI
is set too low then transmissions collide too often. If TI is
set too high then there is excessive unused channel time in
the system (see Setting Transmission Index).
Min Idle Slots and Tx Index can be set differently for different types of packets.
The following table describes the different packet types.
Type Description
Data Packets These are any packets that carry user data. These include
data packets for all the different types of transfers (i.e.
Individual, Individual w/o ACK, Broadcast). These values
are set on the Packet for Port tab.
ACK Packets These are the acknowledgment packets for the individually
addressed data packets. These values are set on the
Packet for Port tab.
Relay Packets These are any packets that are relayed with the store and
forward relay option. Both data packets and ACK packets
can be relayed.
Selection Description
Disabled No network broadcast packets are relayed.
Enabled All network broadcast packets are relayed.
Selection Description
None No broadcast packets are relayed.
Some The broadcast packets that are relayed is determined by
the broadcast relay addresses control.
All All broadcast packets are relayed.
This control consists of a list of broadcast addresses. Each address in the list is
a group address for which broadcast packets are relayed. The user can use as
few or as many (up to the list size) addresses as desired.
CSMA MAC Setup
Network Broadcast
Packets - Relay All
Group Broadcast Packets -
Relay Activate
Broadcast Relay
Addresses
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 25
Selection Description
None No individually addressed packets are relayed.
Some The individual packets that are relayed is determined by the
individual relay addresses control.
All All individually addressed packets are relayed. The
exception is packets whose final destination is the relay
node.
This control consists of a list of address ranges. Each item in the list represents
a range of addresses that are relayed. A packet is relayed if the packet’s source
or destination address matches an address range in the list. The addresses
consist of a group address and a minimum and maximum individual address.
The user can use as few or as many (up to the list size) address ranges as
desired.
These configuration options are set using the Packet for Port tab of the Modem
Configuration.
Control Description
Individual Address The individual address of this modem.
Group Address The group address of this modem. The group address is
used to isolate different sets of individual addresses. It is
also used to filter group broadcast transfers.
Multicast groups allow a modem to receive group broadcasts to groups other than
its own. This allows modems to be combined in subsets and supersets of their
basic groups.
Individual Packets - Relay
Activate
Individual Relay Addresses
Packet for Port
Modem Address
Multicast Group Reception
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 26
Control Description
Enable Multicast
Reception This control enables the multicast capability of the modem
and also enables the entry of multicast groups.
Multicast Groups This control is a list of multicast addresses. These
addresses have the same range as the group addresses.
The user can use as few or as many (up to the list size)
multicast groups as desired.
By default, a modem accepts two kinds of broadcasts.
Network broadcasts are received by all modems.
Group broadcasts are received by modems with the same group address as
the transmitting modem.
Control Description
Max Retries This control sets the maximum number of transmit retries.
A retry is attempted if a packet is sent and an acknowledge
is not received within the time defined by the packet timeout
control. After the maximum number of retries have been
attempted the packet is cleared from the transmit buffer.
Retries do not apply to any kind of broadcast transfers or
individual transfers without acknowledgment.
Max Packet Size This control defines the maximum packet size in bytes. Any
burst that is larger than this number of bytes will be broken
up into multiple packets with this maximum packet size.
Note that there is a difference between bytes and
asynchronous characters. A byte is always eight bits of
data. The number of bits in an asynchronous character is
dependent on the setting of the asynchronous character
control fields.
Packet Timeout The packet timeout is the amount of time the modem waits
for an acknowledgment before re-sending a packet (see
Network Setup - Setting Packet Timeout).
This field selects the type of transfer that the modem defaults to at power up.
This will remain as the transfer type until it is switched using the appropriate
control string.
Selection Description
Individual Transfer This is a standard point to point data transfer with
acknowledgments.
Individual Transfer
w/o Acknowledge This is a point to point data transfer but without any
acknowledgments. This implies that there are no transmit
retries if the packet is received with errors.
Group Broadcast This is a broadcast to a group of modems. Receiving
modems will accept two types of group broadcasts.
Group broadcasts - Broadcasts where the destination
group matches the receiving modem's group.
Multicast broadcasts - Broadcasts where the
destination group matches a group from the receive
modem's multicast group list. For these broadcasts to
be received, the receiving modem must have multicast
reception enabled.
Network Broadcast This is a broadcast to all modems.
Packet Operation
Default Transfer
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 27
These fields select the default destination address that the modem defaults to at
power up. This address will remain as the default until it is switched using the
appropriate control strings.
Type Description
Individual Address The default destination individual address.
Group Address The default destination group address.
Control Description
Provide Address at
Receiver When this control is activated, the source address of each
received packet is sent as a prefix status string to the data
(see Control and Status Strings).
Provide Positive
Transmit ACKs When this control is activated, a status string is sent to the
user when an acknowledgment is received for a packet.
The corresponding packet number of the packet will be
provided as part of the status string (see Control and Status
Strings). This does not apply to any type of broadcast
transfer or individual transfers without acknowledgment.
Provide Negative
Transmit ACKs When this control is activated, a status string is sent to the
user when the transfer of a packet is unsuccessful (all
retries have been sent and no acknowledgment has been
received). The corresponding packet number of the packet
will be provided as part of the status string (see Control and
Status Strings). This does not apply to any type of
broadcast transfer or individual transfers without
acknowledgment.
Control Description
Min Idle Slots This sets the minimum number of idle slots before a
modem attempts transmission (see Setting Min Idle Slots).
If the minimum number of idle slots is set to zero the
modem randomizes its transmission attempts with the first
slot after the channel becomes idle. For values greater
than zero, the modem waits that many slots before
randomizing its transmission attempts.
Tx Index The transmission index (TI) is the inverse of the probability
of transmitting in an idle slot. An index of 4 corresponds to
a 1/4 or 25% chance of transmitting in an idle slot. The goal
of setting TI is to maximize efficiency on the channel. If TI
is set too low then transmissions collide too often. If TI is
set too high then there is excessive unused channel time in
the system (see Setting Transmission Index).
Min Idle Slots and Tx Index can be set differently for different types of packets.
The following table describes the different packet types.
Default Destination
Address
Packet Status Data
CSMA MAC Setup
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 28
Type Description
Data Packets These are any packets that carry user data. These include
data packets for all the different types of transfers (i.e.
Individual, Individual w/o ACK, Broadcast).
ACK Packets These are the acknowledgment packets for the individually
addressed data packets.
Relay Packets These are any packets that are relayed with the store and
forward relay option. Both data packets and ACK packets
can be relayed. These values are set on the Packet
General tab.
Control strings are used to control the operation of the modem. Status strings are
used to provide status information from the modem. Status strings from the
modem can be disabled if they are not needed for a given application. All control
and status strings begin with the ASCII string “+TS”, followed by specific ASCII
letters and numbers corresponding to the particular control field or status value
provided (See Appendix B - ASCII Character Set).
All numbers are formatted as ASCII digits and sent most significant digit first.
iii - Represents a three digit individual address.
gg - Represents a two digit group address.
nn - Represents a two digit packet number.
Control String Description
+TSI Set for individual transfer.
+TSIAiii Set for individual transfer with address change. The three
address characters change the individual destination
address.
+TSICggiii Set for individual transfer with complete address change.
The first two characters are for the group address and the
remaining three are for the individual destination address.
+TSN Set for individual without acknowledgment transfer.
+TSNAiii Set for individual without acknowledgment transfer with
address change. The three address characters change the
individual destination address.
+TSNCggiii Set for individual without acknowledgment transfer with
complete address change. The first two characters are for
the group address and the remaining three are for the
individual destination address.
+TSG Set for group broadcast transfer.
+TSGAgg Set for group broadcast transfer with address change. The
two address characters change the group destination
address.
+TSB Set for a network broadcast transfer (to all modems).
+TSFAggiii Change the modem destination address. The first two
address characters are for the group address and the
remaining three are for the individual address. The type of
transfer remains unchanged.
+TSSnn Set the packet number of the next packet transmitted.
Packet numbers are used in status strings to indicate the
success or failure of the transmission of a particular
Control and Status
Strings
Control Strings
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 29
Control String Description
transmit packet.
The packet number is set to 0 when the modem is reset.
Status String Description
+TSIAggiii Received an individual packet from this address. The first
two address characters represent the group address and
the next three the individual address.
+TSNAggiii Received an individual without acknowledgment packet
from this address. The first two address characters
represent the group address and the next three the
individual address.
+TSGAggiii Received a group broadcast packet from this address. The
first two address characters represent the group address
and the next three the individual address.
+TSBAggiii Received a network broadcast packet from this address.
The first two address characters represent the group
address and the next three the individual address.
+TSSFnn Indicates that the transfer of this packet number was not
successful. This status string is returned after the last retry
of this packet has timed out. This does not apply to any
type of broadcast packet or individual without
acknowledgment packets.
+TSSPnn Indicates that the transfer of this packet number was
successful. This does not apply to any type of broadcast
packet or individual without acknowledgment packets.
A master-slave system is one where the host application is designed so that only
one node will ever attempt to transmit at a given time. An example of this type of
system is a polled system with a base station that sequentially poles a number of
remote nodes. In this case the base always initiates a pole and the remotes
respond with the desired data.
To set up AirNet for this type of system, select the Master-Slave selection in the
Packet General tab of the modem configuration. With this selection, the modem
transmits waiting packets as soon as it detects an idle channel. The master-
slave setting should not be used with systems that use store and forward
repeaters.
The packet timeout timer is used for only for individually addressed packets that
expect an acknowledgment (ACK). The packet timeout timer is started after a
data packet is sent. If an ACK is not received before the timer expires, then a
retry transmission of the data packet is sent. This timer should be set longer than
the worst case time it takes to receive an ACK packet.
For a master-slave system, an ACK packet is sent as soon as the data packet is
received and the channel is idle. This can start as soon as the decay time of the
originating modem is finished.
Packet Timeout Time = Decay Time + Attack Time
+ ACK Packet Transmit Time
Status Strings
Master-Slave
System Setup
Setting Packet
Timeout
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 30
Where:
Decay Time = Tx Decay Time + Additional Transmit Attack Time
Attack Time = Tx Attack Time + Additional Transmit Attack Time
Tx Decay Time and Tx Attack Time are fixed values that are preset
for the radio in the TS4000. These values can be read out of the
TS4000 using the retrieve radio configuration menu or button. The
Additional Transmit Attack Time is the value set on the radio tab of
the modem configuration.
ACK Packet Transmit Time = ACK Packet Length / Modulation Rate
An ACK packet fits in one data frame (16 bytes) of data. If coding is
used then 50% coding overhead is added to this.
ACK Packet Length -Uncoded = 16 bytes x 8 bits per byte = 128 bits
-Coded = 128 bits x 1.5 = 192 bits
Tx Attack Time = 20 ms
Tx Decay Time = 12 ms
Additional Transmit Attack Time = 0 ms
Over air channel rate = 9600 bps
Coding = Enabled
ACK Packet Transmit Time = 192 / 9600 = 20 ms
Packet Timeout Time = 12ms + 20 ms + 20 ms = 52 ms
For a master-slave system, the data packet transmit time is constant for a given
packet size. As long as the channel is not busy, a data packet will be sent
immediately upon becoming available for transmission.
Calculating the delay is very similar to the calculation for the packet timeout time
above.
Total Packet Delay Time = Attack Time + Packet Transmit Time
Where:
Attack Time = Tx Attack Time + Additional Transmit Attack Time
Note that the packet delay time does not include the transmit decay time. This is
because the packet is available at the receiving modem as soon as all the data is
transmitted.
Packet Transmit Time = Packet Length / Channel Rate
Packet Length = (Data Bits + Overhead Bits)
x Framing Overhead x Coding Overhead
Overhead Bits = 14 bytes x 8 bits per byte = 112 bits
Framing Overhead = 1.1
Coding Overhead (optional) = 1.5
Packet Length = (Data Bits + 112) x 1.1 { x 1.5 }
Example:
Data Packet Transmit
Time
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 31
Tx Attack Time = 20 ms
Additional Transmit Attack Time = 0 ms
Over air channel rate = 9600 bps
Number of async chars in packet = 50
Number of data bits per async char = 8
Coding = Enabled
Packet Length = ((50 x 8) + 112) x 1.1 x 1.5 = 845 bits
Packet Transmit Time = 845 / 9600 = 88 ms
Total Packet Delay Time = 20 + 88 = 108 ms
The CSMA MAC (Medium Access Control) is used for systems in which multiple
modems will attempt to access the radio channel simultaneously (multi-access
systems). If two modems attempt to transmit simultaneously, a collision results
which prevents both transmissions from being successfully sent. The AirNet
protocol uses CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance)
to provide multi-access capability. The CSMA refers to monitoring the channel to
ensure that it is unused before transmitting a packet.
Collision Avoidance
For multi-access radio systems CSMA alone is typically not enough to prevent
excessive collisions. The problem occurs when one modem is transmitting and
multiple other modems receive data for their hosts and become ready to transmit.
These other modems will wait until the first modem finishes its transmission and
then all attempt to transmit simultaneously, resulting in a collision. This creates
the need for collision avoidance. The AirNet protocol provides this by having
modems randomize their transmissions once they detect an idle channel. In each
slot after a modem detects an idle channel, it will decide with some probability
(based on the Transmission Index) whether or not to transmit. This does not
eliminate collisions, but, if the probability is set correctly, minimizes the collisions
to allow for efficient multi-access use of the radio channel.
Slot Time
The AirNet protocol uses timing slots to determine when to attempt
transmissions. These slots are slightly different from the slots used in
conventional multi-access slotted MACs. The AirNet slots are the minimum
channel detection times or the minimum time from when one modem begins
transmission to when all other modems will detect that transmission. This size
slot guarantees that modems waiting to transmit in consecutive slots will not
collide and allows for very efficient use of the radio channel.
The following is a summary of the suggested settings for a basic CSMA system.
A basic system does not have any store and forward relays. Note that more
detail on the parameters and equations can be found later in this section.
Slot Time = Attack Time + Maximum Carrier Detect Time Variation
= 1.5 x Attack Time
Where:
Attack Time = Radio Attack Time + Additional Transmit Attack Time
Tx Decay Time and Tx Attack Time are fixed values that are preset
for the radio in the TS4000. These values can be read out of the
TS4000 using the retrieve radio configuration menu or button. The
Additional Transmit Attack Time is the value set on the radio tab of
the modem configuration.
Example:
CSMA System
Setup
Basic System - Setup
Summary
Slot Time
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 32
Min Idle Slots - ACK Packets = 0
Min Idle Slots - Data Packets = 1
Tx Index - ACK Packets = 1
Tx Index - Data Packets = Estimated Backlogged Nodes / Attempt Rate
Where:
Attempt Rate Packet Detection Ratio=
Packet Detection Ratio = Slot Time / Total Packet Time
Total Packet Time = Attack Time + Packet Transmit Time + Decay Time
Packet Transmit Time = Packet Length / Channel Rate
Packet Length = (Data Bits + Overhead Bits)
x Framing Overhead x Coding Overhead
= (Data Bits + 112) x 1.1 { x 1.5 }
Overhead Bits = 14 bytes x 8 bits per byte = 112 bits
Framing Overhead = 1.1
Coding Overhead (optional) = 1.5
Packet Timeout = Decay Time + Attack Time + ACK Packet Transmit Time
Where:
Decay Time = Tx Decay Time + Additional Transmit Attack Time
Attack Time = Tx Attack Time + Additional Transmit Attack Time
ACK Packet Transmit Time = ACK Packet Length / Channel Rate
ACK Packet Length -Uncoded = 16 bytes x 8 bits per byte = 128 bits
-Coded = 128 bits x 1.5 = 192 bits
The following is a summary of the suggested settings for a system that has one
or more store and forward relays. Note that more detail on the parameters and
equations can be found later in this section.
Slot Time = Attack Time + Maximum Carrier Detect Time Variation
= 1.5 x Attack Time
Where:
Attack Time = Radio Attack Time + Additional Transmit Attack Time
Tx Decay Time and Tx Attack Time are fixed values that are preset
for the radio in the TS4000. These values can be read out of the
TS4000 using the retrieve radio configuration menu or button. The
Additional Transmit Attack Time is the value set on the radio tab of
the modem configuration.
Min Idle Slots - ACK Packets = 0
Min Idle Slots - Relay Packets (Relay #1) = 1
Min Idle Slots - Relay Packets (Relay #2) = 2
...
...
Min Idle Slots - Relay Packets (Relay #Z) = Z
Min Idle Slots - Data Packets = Highest Relay # + 1 = Z + 1
Min Idle Slots
Tx Index
Packet Timeout
System with Relays -
Setup Summary
Slot Time
Min Idle Slots
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 33
Tx Index - ACK Packets = 1
Tx Index - Relay Packets = 1
Tx Index - Data Packets = Estimated Backlogged Nodes / Attempt Rate
Where:
Estimated Backlogged Nodes (number of nodes that simultaneously want
to transmit) = the greater of
A) Average Number of Backlogged Nodes or
B) 1/4 Maximum Possible Number of Backlogged Nodes
Attempt Rate Packet Detection Ratio=
Packet Detection Ratio = Slot Time / Total Packet Time
Total Packet Time = Attack Time + Packet Transmit Time + Decay Time
Packet Transmit Time = Packet Length / Channel Rate
Packet Length = (Data Bits + Overhead Bits)
x Framing Overhead x Coding Overhead
= (Data Bits + 112) x 1.1 { x 1.5 }
Overhead Bits = 14 bytes x 8 bits per byte = 112 bits
Framing Overhead = 1.1
Coding Overhead (optional) = 1.5
Packet Timeout = Relay Delays for Data Packet
+ Ack Packet Delay at Destination Node
+ Relay Delays for ACK Packet
Where:
Relay Delays for Data Packet = Relay #1Data Packet Delay
+ Relay #2 Data Packet Delay
...
...
+ Relay #Y Data Packet Delay
Relay #Y Data Packet Delay = Decay Time
+ (Y x Slot Time)
+ Attack Time
+ Data Packet Transmit Time
Data Packet Transmit Time = Data Packet Length / Channel Rate
Data Packet Length = (Data Bits + Overhead Bits)
x Framing Overhead x Coding Overhead
Overhead Bits = 14 bytes x 8 bits per byte = 112 bits
Framing Overhead = 1.1
Coding Overhead (optional) = 1.5
ACK Packet Delay at Destination Node = Decay Time
+ Attack Time
+ ACK Packet Transmit Time
Relay Delays for ACK Packet = Relay #1ACK Packet Delay
+ Relay #2 ACK Packet Delay
...
...
+ Relay #Y ACK Packet Delay
Tx Index
Packet Timeout
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 34
Relay #Y ACK Packet Delay = Decay Time
+ (Y x Slot Time)
+ Attack Time
+ ACK Packet Transmit Time
ACK Packet Transmit Time = ACK Packet Length / Channel Rate
ACK Packet Length -Uncoded = 16 bytes x 8 bits per byte = 128 bits
-Coded = 128 bits x 1.5 = 192 bits
Decay Time = Tx Decay Time + Additional Transmit Attack Time
Attack Time = Tx Attack Time + Additional Transmit Attack Time
The slot time should be set to the attack time of the radio plus the maximum
variation (uncertainty) in the carrier detection circuit. The variation in the carrier
detection circuit is the difference in the carrier detect time between the radio with
the fastest carrier detect time and the radio with the slowest carrier detect time.
Note that the attack time is made up of the worst case transmitter power ramp up
time plus the worst case carrier detect time. Typically the maximum variation of
the carrier detect circuit is less than half (50%) of the attack time.
Slot Time = Attack Time + Maximum Carrier Detect Time Variation
= 1.5 x Attack Time
Attack Time = Tx Attack Time + Additional Transmit Attack Time
Tx Attack Time is a fixed value that is preset for the radio in the
TS4000. This value can be read out of the TS4000 using the retrieve
radio configuration menu or button. The Additional Transmit Attack
Time is the value set on the radio tab of the modem configuration.
The minimum idle slot setting defines the number of slots which a modem will
leave vacant after the modem detects an idle channel and before the modem
attempts to transmit. A setting of 0 means that the modem will begin attempting
transmission in the very first slot after the channel becomes available (idle). A
setting of 1 means that the modem will wait 1 slot after the channel is available
before attempting to transmit. The number of minimum idle slots can be set
differently for each packet type (data, ACK or relay).
The simplest and most efficient system setup is where ACK (acknowledgment)
packets are sent immediately after a valid data packet is received. With this
setup the ACK packets do not contend for the channel the way data packets do.
Correspondingly, the data packets are set so that they will leave the first slot open
for the ACK packets.
This type of setup has the advantage that the delay for receiving an ACK packet
is consistent and predictable. This makes it much easier to set an appropriate
packet timeout (see Setting Packet Timeout).
Min Idle Slots - ACK Packets = 0
Min Idle Slots - Data Packets = 1
Tx Index - ACK Packets = 1 (Always transmit in the first slot)
Tx Index - Data Packets = Attempt Rate (see Setting Tx Index)
Setting Slot Time
Setting Min Idle Slots
Systems without Relays
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 35
For systems with one or more relay nodes, the simplest and most efficient system
setup is where each relay is assigned a particular slot. This way the relays do not
collide or contend for the channel the way data packets do. The data packets are
set so that they will leave the necessary number of slots open for the relays and
ACK packets.
This type of setup has the advantage that the delay for sending data through the
relay(s) is consistent and predictable. This makes it much easier to set an
appropriate packet timeout (see Setting Packet Timeout).
Min Idle Slots - ACK Packets = 0
Min Idle Slots - Relay #1 = 1
Min Idle Slots - Relay #2 = 2
...
...
Min Idle Slots - Relay #N = N
Min Idle Slots - Data Packets = Highest Relay # + 1 = N + 1
Tx Index - Relays (All) = 1 (Always transmit in their assigned slot)
Tx Index - ACK Packets = 1 (Always transmit in the first slot)
Tx Index - Data Packets = Attempt Rate (see Setting Tx Index)
The transmission index (TI) is the inverse of the probability of transmitting in an
idle slot. A TI of 10 corresponds to a 1/10 = 10% chance of transmitting in an idle
slot. The goal of setting TI is to maximize efficiency on the channel. If TI is set
too low then transmissions collide too often. If TI is set too high then there are an
excessive number of unused slots.
AirNet allows TI to be set differently for each packet type (data, ACK or relay).
For most systems, TI is set to 1 for ACK and relay packets (see Setting Min Idle
Slots). The setting of 1 corresponds to always transmitting (100% probability) in a
particular slot.
To set TI, the user must make some practical estimates and then do some
calculations based on these estimates. First it is necessary to estimate the
average data packet length. To do this, estimate the average number of data bits
in a packet using the following formulas.
Packet Length = (Data Bits + Overhead Bits)
x Framing Overhead x Coding Overhead
Overhead Bits = 14 bytes x 8 bits per byte = 112 bits
Framing Overhead = 1.1
Coding Overhead (optional) = 1.5
Packet Length = (Data Bits + 112) x 1.1 { x 1.5 }
With this average packet length number, calculate the packet transmit time. Note
that the formulas require the configuration values for transmit attack and decay
time.
Packet Transmit Time = Packet Length / Channel Rate
Total Packet Time = Attack Time + Packet Transmit Time + Decay Time
Systems with Relays
Min Idle Slots
Tx Index
Setting Tx Index
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 36
Decay Time = Tx Decay Time + Additional Transmit Attack Time
Attack Time = Tx Attack Time + Additional Transmit Attack Time
Tx Decay Time and Tx Attack Time are fixed values that are preset
for the radio in the TS4000. These values can be read out of the
TS4000 using the retrieve radio configuration menu or button. The
Additional Transmit Attack Time is the value set on the radio tab of
the modem configuration.
Calculate the packet detection ratio, which is the slot time normalized to the total
packet time. Then, using packet detection ratio, calculate the attempt rate as its
square root.
Packet Detection Ratio = Slot Time / Total Packet Time
Attempt Rate Packet Detection Ratio=
To finally calculate the transmission index we need to estimate the number of
backlogged nodes (the number of nodes that may want to transmit at the same
time). The difficulty in estimating this value is that for most systems this number
is dynamic and can change dramatically depending on what is occurring in the
system.
For systems where the backlog can vary, estimate the average number of
backlogged nodes for the most common scenario and also estimate the
maximum number of backlogged nodes that will ever occur. If the average
number of backlogged nodes is more than 1/4 of the maximum, then use the
average as the backlog number. Otherwise use 1/4 of the maximum as the
backlog number. The reason for this is that the system must operate under the
worst case conditions. If the backlog is set too low then under worst case
conditions, there will be an excessive number of collisions and the system will be
very slow.
In general it is a good idea to set the transmission index higher than expected as
opposed to lower. This allows the system to more gracefully handle peak traffic.
However, this also causes average efficiency to drop and packet delay time to
increase.
Transmission Index = Estimated Backlogged Nodes / Attempt Rate
Estimated Backlogged Nodes = the greater of
A) Average Number of Backlogged Nodes or
B) 1/4 Maximum Possible Number of Backlogged Nodes
Calculation of the transmission index.
Tx Attack Time = 20 ms
Tx Decay Time = 12 ms
Additional Transmit Attack Time = 0 ms
Over air channel rate = 9600 bps
Coding = Disabled
Average Packet Size = 400 bits
Average Backlogged Nodes = 10
Maximum Backlogged Nodes = 100
Slot Time = 30 ms
Packet Length = (Data Bits + 112) x 1.1 = (400 + 112) x 1.1 = 564
Packet Transmit Time = Packet Length / Channel Rate
= 564 / 9600 = 59 ms
Example:
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 37
Total Packet Time = Attack Time + Packet Transmit Time + Decay Time
= 20 ms + 59 ms + 12 ms = 91 ms
Packet Detection Ratio = Slot Time / Total Packet Time
= 30 ms/ 91 ms = 0.33
Attempt Rate = sqrt(Packet Detection Ratio) = sqrt(0.33) = 0.57
Since: Max Backlogged Nodes / 4 > Average Backlogged Nodes
Estimated Backlogged Nodes = Max Backlogged Nodes / 4
= 100 / 4 = 25
Transmission Index = Estimated Backlogged Nodes / Attempt Rate
= 25 / 0.57 = 44
The packet timeout timer is used for individual packets that expect an
acknowledgment (ACK). This timer is started after a data packet is sent. If an
ACK is not received before the timer expires then a retry transmission of the data
packet is sent. This timer should be set longer than the worst case typical
amount of time it takes to receive an ACK packet.
The following calculations are for systems that are setup so that ACK packets are
sent immediately after the data packet transmission is completed without
contending for the channel (see Setting Min Idle Slots). For this type of CSMA
system the packet timeout time is the same as for a Master/Slave system. The
ACK is sent as soon as the decay time of the sending modem is finished.
Packet Timeout Time = Decay Time + Attack Time
+ ACK Packet Transmit Time
Decay Time = Tx Decay Time + Additional Transmit Attack Time
Attack Time = Tx Attack Time + Additional Transmit Attack Time
ACK Packet Transmit Time = ACK Packet Length / Channel Rate
An ACK packet fits in one data frame (16 bytes) of data. If coding is
used, then 50 % coding overhead is added to this.
ACK Packet Length -Uncoded = 16 bytes x 8 bits per byte = 128 bits
-Coded = 128 bits x 1.5 = 192 bits
The following calculations are for systems that are setup as described in the
Setting Min Idle Slots section. The packet timeout should be set to the amount of
time it takes to send the data packet and then the amount of time it takes to get
back an acknowledgement.
Packet Timeout = Relay Delays for Data Packet
+ Ack Packet Delay at Destination Node
+ Relay Delays for ACK Packet
The amount of time it takes to send a data packet is the sum of the amount of
time it takes each relay to send the data packet.
Relay Delays for Data Packet = Relay #1Data Packet Delay
+ Relay #2 Data Packet Delay
...
...
+ Relay #Y Data Packet Delay
Setting Packet
Timeout
Systems without Relays
Systems with Relays
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 38
The time it takes each relay to send the packet is basically the packet transmit
time. Added to this must be the number of idle slots between the last
transmission and when the current relay decides to transmit.
Relay #Y Data Packet Delay = Decay Time
+ (Y x Slot Time)
+ Attack Time
+ Data Packet Transmit Time
Data Packet Transmit Time = Data Packet Length / Channel Rate
Data Packet Length = (Data Bits + Overhead Bits)
x Framing Overhead x Coding Overhead
Overhead Bits = 14 bytes x 8 bits per byte = 112 bits
Framing Overhead = 1.1
Coding Overhead (optional) = 1.5
The ACK packet delay at the destination node is the amount of time it takes for
the destination node to send the ACK packet.
ACK Packet Delay at Destination Node = Decay Time
+ Attack Time
+ ACK Packet Transmit Time
After the ACK packet is transmitted by the destination node, it must be re-
transmitted by the various relays in the system. This is the sum of the time it
takes each relay to transmit the ACK packet.
Relay Delays for ACK Packet = Relay #1ACK Packet Delay
+ Relay #2 ACK Packet Delay
...
...
+ Relay #Y ACK Packet Delay
Relay #Y ACK Packet Delay = Decay Time
+ (Y x Slot Time)
+ Attack Time
+ ACK Packet Transmit Time
ACK Packet Transmit Time = ACK Packet Length / Channel Rate
ACK Packet Length -Uncoded = 16 bytes x 8 bits per byte = 128 bits
-Coded = 128 bits x 1.5 = 192 bits
Decay Time = Tx Decay Time + Additional Transmit Attack Time
Attack Time = Tx Attack Time + Additional Transmit Attack Time
The average delay is the average amount of time from when a packet is ready for
transmission to when the packet is actually transmitted. This number is for a
single attempt and does not include the time for any retries due to corrupted
transmissions. Note that the average delay varies based on the number of
backlogged nodes in the system at a given time. Also note that the average delay
varies substantially even with constant conditions due to the random nature of
events.
For ease of notation we shall rename some of the parameters.
Data Packet Delay
Average Delay
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 39
Tslot = Slot Time
PDR = Packet Detection Ratio
TI = Transmission Index
N = Backlogged Nodes
PR = (TI - 1)/TI
Average Delay = Tslot x (1 + PDR - PRN)
PDR x ln(1/PR)
Where: ln symbolizes the natural log function.
Using the values from the previous example, calculate the average delay for
various backlogs.
Tslot = Slot Time = 30 ms = 0.03 sec
PDR = Packet Detection Ratio = 0.33 (from previous example)
TI = Transmission Index = 44 (from previous example)
PR = (TI - 1)/TI = (44 - 1)/ 44 = 0.977
Average Delay = Tslot x (1 + PDR - PRN) = 0.03(1 + 0.33 - 0.977N)
PDR x ln(1/PR) 0.33 ln(1/0.977)
= 0.03(1.33 - 0.977N) = 3.91(1.33 - 0.977N)
0.00768
Backlogged Nodes (N) 10 25 50 75 100
Average Delay (sec) 2.1 3.0 4.0 4.5 4.8
The probable delay calculation allows the user to calculate the expected delay
given some probability that the transmission actually occurs. The probable delay
value can be used for calculating a packet timeout value for a system where the
ACK packets do not use an immediate ACK and have a transmission index the
same as the data packets. It can also be used to calculate timeouts for layers of
the protocol stack above the modem on the host system. Note that the probable
delay value does not include any transmission times due to relays and
acknowledgement packets.
The basis of the probable delay is the average delay calculated above. As noted
before, the average delay will vary based on the actual number of backlogged
nodes in a system.
Probable Delay = Average Delay x ln(1/(1 - Probability of Sending))
Where:
The Probability of Sending is a fractionalized percentage (i.e. 50% =
0.50, 95% = 0.95).
Calculate the probable delay for various probabilities of sending in terms of the
average delay.
Probability of Sending (%) 25 50 75 90 95 99 99.9
Probable Delay (Avg. Delays) 0.29 0.69 1.38 2.30 3.00 4.61 6.91
Note that the 50% probability of sending value is not equal to the average delay.
This is because the delay spread is a statistical distribution where the mean and
median delays are not the same.
Example:
Probable Delay
Example:
TS4000 Radio Modem User’s Manual Testing 40
Testing
The TS4000 configuration program is provided with AirTest, Teledesign’s general
purpose wireless modem test software. AirTest can send data and gather
performance statistics about the link between two modems.
To start AirTest press the AirTest button on the main screen of the configuration
program. For details on using AirTest consult AirTest’s on line help.
To test the operation of the TS4000, AirTest can be used to pass data between
two modems.
1) Attach two TS4000s each to a PC serial port.
2) Setup AirTest for the correct serial port baud rate, data bits and parity
(matches the TS4000’s setting).
3) Transmit data between the TS4000s by typing a message into the Tx
Message box of the Comm Port window followed by the ENTER key.
4) Automated tests can be run that will send data and verify that it is received
correctly. To select a test, use the Test Setup command from the Setup
menu. Use the on line help to obtain more information about each test.
A BER (Bit Error Rate) test is used to determine how good a radio environment is
for transmitting data. The BER result tells the percentage of bits that are
corrupted. A BER of 3.0 x 10-4 means that 3 out of 10,000 (104) bits are
corrupted.
AirTest
Data Test
BER Test
TS4000 Radio Modem User’s Manual Testing 41
The longer a BER test runs the more accurate the result. To get an accurate
result a BER test should be run until at least 100 errors have been received. This
provides a 90% confidence level in the BER value. However, in a relatively error
free environment this can take a very long time. An alternative is to run the BER
test until at least 10 errors have been received which provides a 68% confidence
level.
AirTest can be setup to run a BER test. To run a BER test, the TS4000s must be
configured with packet operation disabled. This is because when the TS4000 is
setup for packet operation it discards corrupted packets and does not send them
out the serial port.
1) Attach two TS4000s each to a PC serial port.
2) Setup AirTest for the correct serial port baud rate, data bits and parity
(matches the TS4000’s setting).
3) Select and start one of the automated tests. To select a test, use the Test
Setup command from the Setup menu. Use the on-line help for details about
the different tests.
4) Wait and observe the results.
TS4000 Radio Modem User’s Manual Upgrading Firmware 42
Upgrading Firmware
The TS4000 comes with flash program memory that allows the firmware to be
easily upgraded in the field. Firmware is upgraded with the upgrade program
which is included as part of the TS4000 configuration program.
1) Attach the TS4000 to a PC serial port.
2) Start the upgrade program by pressing the Upgrade Firmware button on the
main screen of the configuration program.
3) Select the firmware version to upgrade to.
a) If the desired firmware version does not show up, us the Find File button
(or menu) to manually search for the necessary file.
4) Press the Connect to Modem button to connect the upgrade program to the
TS4000.
5) Press the Upgrade button and wait for the upgrade to complete.
Upgrading
TS4000 Radio Modem User’s Manual Licensing 43
Licensing
To be operated legally, radio equipment requires two types of licensing; the
manufacturer’s license that the manufacturer obtains and the user license that
the user must obtain.
For most radio equipment, the user is required to obtain an operating license.
This is done so that the government can coordinate radio users in order to
minimize interference.
It is the user’s responsibility to obtain the necessary licenses prior to
transmitting over the air with the TS4000. The user is also responsible for
proper setup, operation, and maintenance of the TS4000 so that it complies with
the limits specified by the license.
Changes or modifications not expressly approved by Teledesign Systems
Inc. could void the user’s authority to operate this equipment.
Shielded cable must be used with this equipment in order to ensure that it meets
the emissions limits for which it was designed. It is the responsibility of the user
to obtain and use good quality shielded interface cables with this device.
Shielded interface cables are available from most retail and commercial suppliers
of interface cables designed to work with personal computer peripherals.
Within the different frequency bands (i.e. VHF, UHF, 900 MHz etc.) channels are
licensed with a specific channel spacing (i.e. 25 kHz, 12.5kHz, etc.). The channel
spacing corresponds to difference between the center frequency of adjacent
channels. The TS4000 can be ordered with various channel spacing options.
For each frequency band and channel spacing, there is a corresponding
maximum occupied bandwidth. The maximum occupied bandwidth is the amount
of frequency bandwidth that the user on a channel is allowed to occupy. This is
typically (but not always) less than the channel spacing in order to minimize
interference between users on adjacent channels.
The occupied bandwidth of the TS4000 can be configured by the user (see Radio
Setup). The occupied bandwidth must be set to a value less than or equal to the
maximum allowed occupied bandwidth of the channels that the user is operating
on. Note that the setting of occupied bandwidth limits the maximum over the air
data rate that the TS4000 can operate at. The maximum over the air data rate is
also dependent on the modulation type selected.
For each TS4000 there is a maximum occupied bandwidth that cannot be
exceeded and is dependent on the bandwidth of the specific radio module that
the unit was ordered with. This maximum occupied bandwidth is configured
when the unit is manufactured and cannot be changed by the end user.
Within the US, the FCC indicates the maximum occupied bandwidth as part of
the channel emission designator. For example, an emission designator of
16K0F1D corresponds to a 16.0 kHz occupied bandwidth. The emission
designator of the licensed channel or channels shows up on the license form that
is received when the FCC (or other appropriate licensing agency) grants a
license.
User’s License
Channel Spacing and
Occupied Bandwidth
TS4000 Radio Modem User’s Manual Licensing 44
The TS4000 is licensed under the FCC (Federal Communications Commission)
Part 90 rules. The FCC regulates the operation and licensing of radio equipment
in the US. To obtain a license to operate radio equipment a user must fill out the
appropriate FCC forms and pay an application fee.
Many FCC licenses also require that the user obtain frequency coordination from
the appropriate organization. The coordination organizations handle the up front
work of qualifying applications and allocating channels. The appropriate
coordination organization depends on the type of license (voice, data, paging,
etc.), type of user (business, government, etc.) and the frequencies
To help with the licensing process, there are companies who, for a fee, will fill out
and file the paperwork necessary to obtain a license.
Atlas License Company 800-252-0529
LAO (Licensing Assistance Office) 717-337-9630
FCC 888-225-5322
PCIA 800-759-0300 (Coordination agency for most business licenses)
Countries other than the USA have different rules for operating radio equipment.
The user should work with the appropriate government agency to obtain the
necessary licenses and to make sure that the TS4000 meets the licensing
requirements.
To sell most radio equipment, the manufacturer must obtain a license that
guarantees that their equipment meets the necessary regulations for operation.
The regulations vary based on the country and frequency of operation.
The TS4000 has been tested and found to comply with the limits for a Class B
digital device, pursuant to Part15 of the FCC rules (Code of Federal Regulations
47CFR Part 15). Operation is subject to the condition that this device does not
cause harmful interference.
The TS4000 has been type accepted for operation by the FCC in accordance with
Part 90 of the FCC rules (47CFR Part 90). See the label on the unit for the
specific FCC ID and any other certification designations.
The TS4000 has been type accepted for operation by the FCC in accordance with
Part 101 of the FCC rules (47CFR Part 101). See the label on the unit for the
specific FCC ID and any other certification designations.
This Class B digital apparatus meets all requirements of the Canadian
Interference-Causing Equipment Regulations.
The TS4000 has been certified for operation by Industry Canada in accordance
with RSS-119 and RSS-210 of the Industry Canada rules. See the label on the
unit for the specific Industry Canada certification number and any other
certification designations.
Many countries allow radio equipment that meets the FCC rules to be operated.
However, some countries have their own rules which radio manufactures must
USA (FCC)
Licensing Service
Companies
Phone Numbers
International
Manufacturer’s
License
USA (FCC) Part 15
Part 90
Part 101
Industry Canada
ICES-003
RSS-119
International
TS4000 Radio Modem User’s Manual Licensing 45
comply with. It is the user’s responsibility to ensure that the TS4000 meets the
required regulations.
TS4000 Radio Modem User’s Manual Service and Support 46
Service and Support
We at Teledesign Systems are committed to providing excellent service and
support to our customers. Our goal is to make using our products as easy and
painless as possible. To accomplish this Teledesign provides free technical
support for all our products during all phases of sales, installation, and use.
Service and technical support can be reached during our normal business hours
of 8 AM to 5 PM (Pacific Standard Time) Monday through Friday. Teledesign
Systems can be reached at the following phone numbers.
(800) 663-3674 or (800) MODEMS-4 (USA & Canada)
(408) 232-0180
(408) 232-0188 (Fax)
We can reached by email at:
support@teledesignsystems.com
corpcomm@teledesignsystems.com
sales@teledesignsystems.com
We can be reached by mail at:
Teledesign Systems Inc.
2635 North First Street, Suite 205
San Jose, CA 95134-2032
USA
In addition we have a web site which contains our latest product information and
downloads:
www.teledesignsystems.com
Before returning equipment to Teledesign, please call for an RMA number and
shipping information. This allows us to plan for your shipment in order to provide
the best possible service. When returning equipment, please include a note
indicating the symptoms of the failure and any other pertinent information.
Contacting
Teledesign
Returning
Equipment
TS4000 Radio Modem User’s Manual Warranty 47
Warranty
Teledesign Systems Inc. warrants this product to be free from defects in
materials and workmanship for a period of two (2) years from the date of
shipment. During the warranty period, Teledesign Systems Inc. will, at its option,
either repair of replace products that prove to be defective.
This warranty shall not apply to any defect, failure or damage caused by misuse,
abuse, improper application, alteration, accident, disaster, negligence, use
outside of the environmental specifications, improper or inadequate maintenance,
or incorrect repair or servicing not performed or authorized by Teledesign
Systems Inc.
TELEDESIGN SYSTEMS INC. SHALL IN NO EVENT HAVE OBLIGATIONS OR
LIABILITIES TO BUYER OR ANY OTHER PERSON FOR LOSS OF PROFITS,
LOSS OF USE OR INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES,
WHETHER BASED ON CONTRACT, TORT (INCLUDING NEGLIGENCE),
STRICT LIABILITY, OR ANY OTHER THEORY OR FORM OF ACTION, EVEN
IF TELEDESIGN SYSTEMS INC. HAS BEEN ADVISED OF THE POSSIBILITY
THEREOF, ARISING OUT OF OR IN CONNECTION WITH THE SALE,
DELIVERY, USE, REPAIR, OR PERFORMANCE OF THIS PRODUCT
(INCLUDING EQUIPMENT, DOCUMENTATION AND SOFTWARE). IN NO
EVENT SHALL THE LIABILITY OF TELEDESIGN SYSTEMS INC. ARISING IN
CONNECTION WITH ANY PRODUCT EXCEED THE ACTUAL AMOUNT PAID
FOR SUCH PRODUCT.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, WRITTEN OR
ORAL, EXPRESSED OR IMPLIED, INCLUDING IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Two Year Warranty
Exclusions
Limitations
TS4000 Radio Modem User’s Manual Appendix A - Serial Ports 48
Appendix A - Serial Ports
Connector
The standard case uses a DE-9 subminiature 9 pin D connector with female pins
for each serial port.
Pin Signal Direction Notes
1 Data Carrier Detect (DCD) Output
2 Receive Data (RD) Output
3 Transmit Data (TD) Input
4 Data Terminal Ready (DTR)
Alt) Modem Power
Input
Input
[1] [2]
5 Signal Ground (SG) --
6 Data Set Ready (DSR)
Alt) Always in high state
Output
Output
[1] [3]
7 Request to Send (RTS) Input
8 Clear to Send (CTS) Output
9 Not Connected
Alt) Data Set Ready (DSR)
Alt) Modem Power
--
Output
Input
[1] [4]
Pin Signal Direction Notes
1 Data Carrier Detect (DCD) Output
2 Receive Data (RD) Output
3 Transmit Data (TD) Input
4 Data Terminal Ready (DTR) Input
5 Signal Ground (SG) --
6 Data Set Ready (DSR)
Alt) Always in high state
Output
Output
[1] [3]
7 Request to Send (RTS) Input
8 Clear to Send (CTS) Output
9 Not Connected
Alt) Data Set Ready (DSR)
Alt) Modem Power
--
Output
Input
[1] [4]
Connector
The watertight case uses a single 19 pin LEMO HCG.2B.319 connector with
female pins. The recommended mating plug for this connector is a LEMO
FGG.2B.319 series cable mounted connector.
Pin Port Signal Direction Wire Color [6] Notes
1 2 Signal Ground (SG) --
2 2 Data Terminal Ready (DTR) Input
3 2 Transmit Data (TD) Input
4 2 Receive Data (RD) Output
5 2 Data Carrier Detect (DCD) Output
6 1 Signal Ground (SG) --
7 1 Data Terminal Ready (DTR) Input [5]
8 1 Transmit Data (TD) Input
Standard Case
Serial Port 1 Pinout
Serial Port 2 Pinout
Watertight Case
Pinout
TS4000 Radio Modem User’s Manual Appendix A - Serial Ports 49
Pin Port Signal Direction Wire Color [6] Notes
9 1 Receive Data (RD) Output
10 1 Data Carrier Detect (DCD) Output
11 -- Ground (Power) --
12 -- Modem Power Input
13 2 Clear To Send (CTS) Output
14 2 Request To Send (RTS) Input
15 2 Data Set Ready (DSR)
Alt) Always in high state
Output
Output
[1] [3]
16 1 Not Connected
Alt) Data Set Ready (DSR)
--
Output
[1] [4]
[5]
17 1 Request To Send (RTS) Input
18 1 Data Set Ready (DSR)
Alt) Always in high state
Output
Output
[1] [3]
19 1 Clear To Send (CTS) Output
[1] These pins have multiple internal signals that they can be connected to. The
connection options are selected with internal jumper plugs (see Appendix F -
Internal Jumper Block).
[2] This pin is normally setup as the serial port Data Terminal Ready (DTR) line,
which is an input for DCEs (input to the TS4000). As an alternative, this pin
can be setup to feed DC power into the TS4000.
Caution: The use of the DTR pin for a DC power input connection is
non-standard. Therefore the TS4000 serial port must not be connected
to a standard serial device that drives the DTR pin (i.e. a PC). This
results in the power supply voltage of the TS4000 being shorted to the DTR
output of the host serial port, which could damage to the host device.
Therefore, when connecting the TS4000 to a PC for configuration, make sure
that the cable does not have a DTR (pin 4) connection.
[3] This pin is normally setup as the serial port Data Set Ready (DSR) line, which
is an output for DCEs (output of the TS4000). As an alternative, this pin can
be set to always be in the active high state. In this case the pin is internally
connected to +5 volts through a 1 KΩ resistor.
[4] For standard RS-232 ports this pin is the Ring Indicator (RI) line, which is an
output for DCEs (the TS4000). However, the TS4000 does not have an RI
line internally. Instead, this pin can be connected to the serial port Data Set
Ready (DSR) line which is an output for DCEs (output of the TS4000), or this
pin can be setup to provide DC power into the TS4000.
The use of this pin as a power pin is non-standard and therefore care should
be taken when connecting the TS4000 to standard serial devices. For most
serial ports this is not a problem because RI is a modem (DCE) output and
the TS4000 power supply mostly falls within the allowed voltage range for
RS-232 signals. Therefore the power voltage on this pin is interpreted as an
active RI signal. For systems that use the RI signal differently, or that cannot
operate with power on this pin, this pin should be disconnected between the
TS4000 and the host equipment.
[5] For the watertight version of the TS4000, the alternate jumper block option to
supply power to the modem via this pin should not be used due to the
Notes:
TS4000 Radio Modem User’s Manual Appendix A - Serial Ports 50
amperage limitation of the flex circuit connecting the LEMO connector to the
modem board.
[6] These are the wire colors of the internal wires for the standard cable provided
with the watertight version of the TS4000.
Signal Connector Pinout Direction
Signal Name Mnemonic 9 Pin 25 Pin DCE DTE
Signal Ground SG 5 1, 7 -- --
Transmit Data TD 3 2 Input Output
Receive Data RD 2 3 Output Input
Request to Send RTS 7 4 Input Output
Clear to Send CTS 8 5 Output Input
Data Carrier Detect DCD 1 8 Output Input
Ring Indicator RI 9 22 Output Input
Data Set Ready DSR 6 6 Output Input
Data Terminal Ready DTR 4 20 Input Output
Signal Description
Request to Send (RTS) Request for transmission from the DTE.
Clear to Send (CTS) Response (to the Request to Send) from the DCE
indicating a readiness to transmit data.
Data Carrier Detect (DCD) Status from the DCE indicating that it is receiving.
Ring Indicator (RI) Status from the DCE indicating that it has detected
the ring state.
Data Set Ready (DSR) Status from the DCE indicating that it is
operational.
Data Terminal Ready (DTR) Status from the DTE indicating that it is
operational.
Serial port 1 can be configured for either RS-232 or TTL signal levels. The signal
level selection is controlled with internal jumper plugs (see Appendix F - Internal
Jumper Block).
The RS-232 standard defines minimum and maximum voltage levels for the
drivers and receivers. However, in practice the drivers and receivers work
correctly with signal levels that are different from the specification.
Level (volts DC)
Type Low High
Drivers (into a 3k to 7k ohm load)
RS-232 Specification
Actual TS4000 Drive Levels -15 to -5
-9 to -6 +5 to +15
+6 to +9
Receivers (with 3k to 7k ohm load)
RS-232 Specification
Actual TS4000 Receive Levels -25 to -3
-25 to +0.8 +3 to +25
+2.4 to +25
Standard RS-232
Serial Port Pinout
Standard Usage of
the RS-232 Control
Signals
Signal Levels
RS-232 Signal Levels
TS4000 Radio Modem User’s Manual Appendix A - Serial Ports 51
Level (volts DC)
Type Low High
Output (Driver) 0.0 to +0.4
(sinking up to 4 mA) +3.0 to +5.0
(sourcing up to 4 mA)
Input (Receiver) -25 to +0.8 +2.4 to +25
(3k to 7k ohm load)
The signal polarity is the same for both RS-232 and TTL operation.
Level State
Voltage Low Mark
Control signal inactive
Stop bit state (end of async character)
Logic one data bit state (within async character)
Voltage High Space
Control signal active
Start bit state (beginning of async character)
Logic zero data bit state (within async character)
TTL Signal Levels
Signal Polarity
TS4000 Radio Modem User’s Manual Appendix B - ASCII Character Set 52
Appendix B – ASCII Character Set
Control Value
Char Char Dec Hex
Ctrl-@NUL 0 00
Ctrl-A SOH 1 01
Ctrl-B STX 2 02
Ctrl-C ETX 3 03
Ctrl-D EOT 4 04
Ctrl-E ENQ 5 05
Ctrl-F ACK 6 06
Ctrl-G BEL 7 07
Ctrl-H BS 8 08
Ctrl-I HT 9 09
Ctrl-J LF 10 0A
Ctrl-K VT 11 0B
Ctrl-L FF 12 0C
Ctrl-M CR 13 0D
Ctrl-N SO 14 0E
Ctrl-O SI 15 0F
Ctrl-P DLE 16 10
Ctrl-Q DC1 17 11
Ctrl-R DC2 18 12
Ctrl-S DC3 19 13
Ctrl-T DC4 20 14
Ctrl-U NAK 21 15
Ctrl-V SYN 22 16
Ctrl-W ETB 23 17
Ctrl-X CAN 24 18
Ctrl-Y EM 25 19
Ctrl-Z SUB 26 1A
Ctrl-[ ESC 27 1B
Ctrl-\ FS 28 1C
Ctrl-] GS 29 1D
Ctrl-^ RS 30 1E
Ctrl-_US 31 1F
Value
Char Dec Hex
SP 32 20
!3321
“3422
#3523
$3624
%3725
&3826
‘3927
(4028
)4129
*422A
+432B
‘442C
-452D
.462E
/472F
04830
14931
25032
35133
45234
55335
65436
75537
85638
95739
:583A
;593B
<603C
=613D
>623E
?633F
Value
Char Dec Hex
@64 40
A6541
B6642
C6743
D6844
E6945
F7046
G7147
H7248
I7349
J744A
K754B
L764C
M774D
N784E
O794F
P8050
Q8151
R8252
S8353
T8454
U8555
V8656
W8757
X8858
Y8959
Z905A
[915B
\925C
]935D
^945E
_95 5F
Value
Char Dec Hex
‘9660
a9761
b9862
c9963
d 100 64
e 101 65
f 102 66
g 103 67
h 104 68
i 105 69
j 106 6A
k 107 6B
l 108 6C
m 109 6D
n 110 6E
o 111 6F
p 112 70
q 113 71
r 114 72
s 115 73
t 116 74
u 117 75
v 118 76
w 119 77
x 120 78
y 121 79
z 122 7A
{ 123 7B
| 124 7C
} 125 7D
~ 126 7E
DEL 127 7F
TS4000 Radio Modem User’s Manual Appendix C - Specifications 53
Appendix C - Specifications
Data Rates 300, 1200, 2400, 4800, 9600, 19200, 38400 baud
Data Format Asynchronous, 8 or 9 bit words
Signal Levels RS-232, TTL (Port 1 only) or RS-485
Handshake Protocols Full Handshake: Supports RTS, CTS, DCD, DSR, DTR
Data Activation (3 wire): Requires only TXD, RXD and SG
Data Only Time Out 1 to 500 character periods
Data Connector 9 pin D, female, DCE (standard case)
LEMO sealed connector (watertight case)
Frequency Ranges 132-208, 380-520, 928-960 MHz
Number of Channels 99 receive/transmit pairs (in non-volatile memory)
Channel Spacing 5, 6.25, 7.5, 10, 12.5, 15, 25, 30 kHz
Channel Rate 2,400 to 19,200 bps
Modulation Filtered MSK, GMSK and 4 Level FSK
RF Output Power 100 milliwatts to 5 watts,
External amplifiers available for up to 100 watts
Receive Data Sensitivity -104 dBm for less than 1 x 10-6 BER (Bit Error Rate) (typical)
Carrier Detect Threshold -110 to -60 dBm, programmable
RF Connector BNC, female, 50 Ω (standard case)
TNC, female, 50 Ω (watertight case)
Data Protocol Transparent or Packet
Data Security 254 Selectable Scrambling Codes
FEC (Coding) None or 12,8 Hamming code with 16 bit Interleaving
Channel Access Master-Slave or Carrier Sense Multiple Access (CSMA) with
Programmable Attempt Rate
Protocol Automatic Repeat reQuest (ARQ)
Packet Size 1 to 5000 characters
Retries 0 to 50 per packet
Address Space 999 Individual Addresses per Group
60 Groups
Transfers Individual with Acknowledgment (to any address)
Individual without Acknowledgment (to any address)
Group Broadcast (to all addresses in a single group)
Network Broadcast (to all addresses in all groups)
Multicast Reception (from up to 20 other groups)
Relay Operation Store and Forward with Address Filtering
Supply Voltage 9 to 28 VDC
Power 0.5 watts - Standby (typical)
0.75 watts - Receive (typical)
7 to 22 watts - Transmit (depends on transmit power)
Power Connector 2 pin Molex or through serial port
Data Buffer 32 KByte SRAM
Program Storage 512 KByte Flash ROM (supports in field firmware upgrades)
LED Indicators Transmit, Receive, Power
Operating Temperature -22 to +140 °F (-30 to +60 °C)
Dimensions 4.3" x 3.1" x 1.8" (109 mm x 79 mm x 46 mm)
Weight 12 ounces (340 grams)
Enclosure Options Standard and Watertight
Data Interface
Radio - General (varies
based on specific model)
Channel Options
Optional Packet Protocol
General
TS4000 Radio Modem User’s Manual Appendix D - Case Dimensions 54
Appendix D - Case Dimensions
TS4000 Radio Modem User’s Manual Appendix E - PCB Component Locations 55
Appendix E - PCB Component Locations
TS4000 Radio Modem User’s Manual Appendix F - Internal Jumper Block 56
Appendix F - Internal Jumper Block