Intermec Technologies WANRIM902-6100 WIRELESS DATA TERMINAL User Manual RIM 902M Integrator s Guide

Intermec Technologies Corporation WIRELESS DATA TERMINAL RIM 902M Integrator s Guide

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RIM 902M OEM Radio Modem Integrator’s Guide

Last Updated: January 11, 1999

Model No. R902M-2-O

Research In Motion and RIM are registered trademarks of Research In Motion Ltd.

Mobitex is a trademark of the Swedish Telecommunications Administration.

MS-DOS is a registered trademark, and Windows is a trademark, of Microsoft Corp.

Warning: This document is for the use of licensed users only. Any unauthorised

copying, distribution or disclosure of information is a violation of copyright laws.

While every effort has been made to ensure technical accuracy, information in this

document is subject to change without notice and does not represent a commitment on

the part of Research In Motion Limited.

Research In Motion

295 Phillip Street

Waterloo, Ontario

Canada N2L 3W8

tel. (519) 888-7465

fax (519) 888-7884

E-mail: rim902m@rim.net

Web site: www.rim.net

MOBITEX Interface, specified

in Specification

LZBA 703 1001,

compatible equipment

FCC Compliance Statement (USA)

FCC Class B Part 15

This device complies with Part 15 of FCC Rules. Operation is subject to

the following two conditions:

1. This device may not cause harmful interference, and

2. This device must accept any interference received, including

interference that may cause undesired operation.

Warning

Changes or modifications to this unit not expressly approved by the

party responsible for compliance could void the user’s authority to

operate this equipment.

This equipment has been tested and found to comply with the limits for a

Class B digital device, pursuant to Part 15 of the FCC Rules. These

limits are designed to provide reasonable protection against harmful

interference in a residential installation. This equipment generates, uses

and can radiate radio frequency energy and, if not installed and used in

accordance with the manufacture’s instructions, may cause harmful

interference to radio communications.

There is no guarantee, however, that interference will not occur in a

particular installation. If this equipment does cause harmful interference

to radio or television reception, which can be determined by turning the

equipment off and on, the user is encouraged to try to correct the

interference by one or more of the following measures:

Re-orient or relocate the receiving antenna.

Increase the separation between the equipment and receiver.

Connect the equipment into an outlet on a circuit different from

that to which the receiver is connected.

Consult the dealer or an experienced radio/TV technician for

help.

Industry Canada Certification

This device complies with Industry Canada RSS 119, under certification

number TBD.

IC Class B compliance

This device complies with the Class B limits for radio noise emissions as set

out in the interference-causing equipment standard entitled “Digital

Apparatus,” ICES-003 of Industry Canada.

Contents

FCC Compliance Statement (USA) ........................................i

Industry Canada Certification ...............................................ii

About this guide.................................................................... v

1. Introduction............................................................... 1

Radio performance...................................................................... 1

Mobitex network technology....................................................... 4

FCC radio frequency exposure rules............................................ 5

2. Getting started........................................................... 9

Test board overview...................................................................10

How to connect the test board.....................................................11

The MENU diagnostics tool.......................................................12

3. Mechanical integration ........................................... 21

Environmental properties...........................................................21

Physical properties.....................................................................22

Mounting methods.....................................................................24

Cables and connectors................................................................27

4. Power requirements ................................................ 31

Load specifications ....................................................................31

Batteries ....................................................................................32

Plug-in supplies .........................................................................34

Automotive supplies...................................................................34

5. Interface specification............................................. 35

MASC and RAP link-layer protocols .........................................35

Pin descriptions .........................................................................37

How to turn the radio on and off ................................................42

Interface to an RS-232 device.....................................................43

Interface to microprocessor ........................................................43

6. Antenna selection .................................................... 45

Selecting an antenna..................................................................45

Introduction to antenna terminology ..........................................46

Positioning the antenna..............................................................49

Shielding ...................................................................................50

Specifications ...................................................................... 51

Glossary of terms ................................................................ 53

Index.................................................................................... 55

About this guide

This document is a guide to integrating the RIM 902M OEM radio modem into

a variety of devices such as laptop computers, handhelds, vending machines,

point-of-sale terminals, vehicle-based mobile terminals, and alarm system.

Topics covered in this guide include:

mounting requirements

power (battery) characteristics

interfacing to the RIM 902M

antenna selection and placement

Throughout the guide, there are suggestions and precautions that will ease the

implementation of a wireless communication solution. These recommendations

are based on years of experience integrating wireless modems into a variety of

devices. You are welcome and encouraged to contact RIM if you would like to

discuss the technical implementation of this radio modem.



1. Introduction

With the introduction of the RIM 902M, Research In Motion (RIM) has set a

new standard for radio modem performance. The RIM 902M is unrivaled in the

key areas of receiver sensitivity, ouput efficiency, noise immunity, and power

consumption. Its small size and weight make it suitable for virtually any

wireless data application, including handheld devices and mobile terminals.

The RIM 902M is designed for use with Mobitex wide-area wireless data

networks operating in the 900 MHz range, such as the BellSouth Intelligent

Wireless Network.

RIM radio modems are specifically designed to integrate easily into a computer

or other embedded system. Potential applications include:

Laptop computers Vehicle tracking and location

Point of sale devices Monitoring and telemetry

Ruggedized terminals Vending machines

Handheld PC’s Utility meters

Parking meters Billboards

Dispatching Security alarm panels

Radio performance

The RIM 902M offers the highest performance of any radio modem for

Mobitex wireless data networks:

2 Introduction – Radio performance

Integrator’s Guide – RIM 902M OEM Radio Modem

Receiver sensitivity

Receiver sensitivity is a measure of how well a radio modem can “hear” a

network base station. This figure is important when a device will be used in

areas where signal strength is weak, such as inside buildings and in locations

that are not close to a base station. A radio modem with good receiver

sensitivity can be used in more places than a radio modem with poor sensitivity.

The RIM 902M has a receiver sensitivity of –118 dBm, or 0.0016 picowatts.

This is the strength of the weakest digital signal that can be interpreted with a

1% bit error rate. Although 1% may seem high, the sophisticated over-the-air

Mobitex protocol corrects these errors before the data is passed to the

application, ensuring error-free communication. This capability is already built

into the radio’s firmware, and does not require any additional software

development.

Noise immunity

The RIM 902M is not de-sensitized by the electromagnetic interference (EMI)

or “noise” that is generated by the electronics of the terminal into which it is

integrated. As a result, no special shielding is required between the radio and

your device.

Noise immunity offers several benefits, including:

easier integration improved RF performance

longer battery life more coverage from each base station

increased reliability no need for special RF shielding

Powerful and efficient transmitter

When necessary, the RIM 902M can supply a full 2.0 watts to the antenna.

However, the RIM 902M quickly decreases the output power when it is close to

a base station to as little as 0.06 watt – because a stronger signal is needed

only when far from a base station. By transmitting a strong signal only when

necessary, the RIM 902M conserves battery power.

The RIM 902M provides reliable transmit efficiency across the entire operating

voltage range of 4.15 to 4.75 volts. As a result, batteries can be used even when

nearing depletion. This also maximizes the radio coverage area throughout the

life of the battery.

Introduction – Radio performance 3

RIM 902M OEM Radio Modem – Integrator’s Guide

Low power requirements

If you are planning to integrate the RIM 902M into a handheld or portable

device, battery life is a critical issue: your customers will insist on long lasting

devices without heavy battery packs. The RIM 902M sets a new power

consumption standard for Mobitex radio modems. This ensures efficiency and

maximizes battery life.

Transmitting data: 1.7 amps or less (at 4.5V), depending on output power

The transmitter is ON for a pulse of between 32 ms and 1 second per

packet, depending on the amount of data transmitted. The maximum

packet size for a Mobitex device is 512 bytes.

Receiving data: 60 mA (at 4.5V)

The radio turns its receiver ON for a 150 ms “window” once every 10

seconds. The base station will only attempt to communicate with the radio

during this window. To minimize latency during rapid two-way

communication, the receiver is also turned ON and kept ON for 10

seconds after any communication (transmit or receive) with the network.

Standby power: 0.3 mA (at 4.5V)

Standby power consumption is very low and occurs when no radio activity

has taken place for at least 10 seconds. The radio and base station are

closely synchronized to ensure that a communication attempt is not missed

when the radio is in standby mode.

Battery life is not a concern for certain applications, such as in-vehicle

applications that draw power from the vehicle battery. For these applications, it

is possible to put the radio in an express operating mode, in which power

consumption is higher than normal but packet transfer latency is reduced to a

minimum.

Small size

Using a single board design, the RIM 902M is very thin, and much smaller

than a business card, at only 42.0 by 67.5 mm. This tiny size allows the

RIM 902M to meet tight space requirements within most applications. The fact

that a single board is used means that the device is much more reliable than

multi-board designs, particularly in high-vibration environments such as

vehicles.

4 Introduction – Mobitex network technology

Integrator’s Guide – RIM 902M OEM Radio Modem

Mobitex network technology

The Mobitex wireless network technology, developed by Eritel in 1984 for

Swedish Telecom, has become an international data communication standard.

Now managed by the Mobitex Operators Association (MOA), which controls

the specifications for this open standard, Mobitex is a secure, reliable, wireless

packet switching network specifically designed for wide-area wireless data

communications.

Mobitex networks are deployed around the world. The technology is presently

available in the following countries:

Australia Germany Singapore

Austria Indonesia Sweden

Belgium Italy Turkey

Canada Korea United Kingdom

Chile Netherlands United States

Finland Norway Venezuela

France Poland

Mobitex networks in the United States, Canada, Korea, Chile, and Venezuela

operate in the 900 MHz range, and are therefore directly compatible with the

RIM 902M OEM radio modem. Currently, Mobitex networks in other countries

operate at other frequencies, such as 400 MHz.

Mobitex provides highly reliable, two-way digital data transmission. The

network provides error detection and correction to ensure the integrity of the

data being sent and received, and includes transmission acknowledgment.

The Mobitex network has a hierarchical structure that allows messages to be

routed from sender to receiver along the most direct path possible. Each radio

cell is served by an intelligent base station. Because intelligence is distributed

throughout the network, data is only forwarded to the lowest network node

common to the sender and the receiver. For example, one base station is able to

handle all traffic in its coverage area.

The network constantly monitors the location of the mobile users. As a mobile

moves from one area of coverage to another, base stations track its signals,

sending updated mobile location and status information to the network. If the

network goes down at any point in transmission, the message is held until

network service is restored. If the mobile receiver moves outside the coverage

area, the base station stores the data until coverage is re-established, then

Introduction – FCC radio frequency exposure rules 5

RIM 902M OEM Radio Modem – Integrator’s Guide

forwards it to the mobile. This prevents data loss, and increases the reliability

of transmission.

Mobitex is optimized for data communication. It uses a packet switching

technique to provide the greatest flexibility in data transmission. Conventional

cellular phone systems, by contrast, use a circuit-switched network, in which a

physical connection is created between the sending and receiving nodes, and

must be maintained throughout the duration of the transmission. With circuit-

switched systems, the set-up time for establishing a connection involves

significant overhead and airtime cost, especially when only a small amount of

data needs to be transferred.

Mobitex packets include information about the origin, destination, size, type,

and sequence of data to be sent. This enables packets to be transmitted

individually, in any order, as traffic permits. Internal to the network, individual

packets may travel along different routes, in any order, without interfering with

other packets sent over the same frequency by different users. At the receiving

end, all packets are accounted for, and reassembled into the original message.

Set up time is eliminated and network connection is instantaneous. As a result,

packet-switching makes far more efficient use of channel capacity, typically

allowing 10 to 50 times more users over a radio channel than a circuit switched

network.

FCC radio frequency exposure rules

Based on FCC rules 2.1091 and 2.1093(1) and FCC Guidelines for Human

Exposure to Radio Frequency Electromagnetic Fields, OET Bulletin 65 and its

Supplement C(2), all integrations of the RIM 902M OEM unit are subject to

routine environmental evaluation for RF exposure prior to equipment

authorization or use.

For portable devices, defined in accordance with FCC rules as a transmitting

device designed to be used within 20 cm of the user body under normal

operating conditions, RF evaluation must be based on Specific Absorption Rate

(SAR) limits in Watts/kg. SAR is a measurement of the rate of energy

absorption per unit mass of body tissue.

For mobile devices, defined as a transmitting device designed to be generally

used such that a separation distance of at least 20 cm is maintained between the

6 Introduction – FCC radio frequency exposure rules

Integrator’s Guide – RIM 902M OEM Radio Modem

body of the user and the transmitting radiated structure, the human exposure to

RF radiation can be evaluated in terms of Maximum Permissible Exposure

(MPE) limits for field strength or power density in mWatts/cm2.

RIM will submit module specific information and test reports for a generic

MPE compliance. For an end product not covered by RIM testing and

submission, the integrator will submit for a separate FCC ID. The submission

should include end product information, end product SAR/MPE test report and

a reference to RIM module FCC ID for all other Part 90 requirements.

SAR and MPE limits

SAR limits for General Population/Uncontrolled exposure is 1.6 W/kg for

partial body exposure, averaged over 1 g of tissue and 4 W/kg for hands, wrists

and feet averaged over 10 g of tissue. The limits for Occupational/Controlled

exposure are more relaxed, i.e., 8 W/kg for partial body and 20 W/kg for hands,

wrists and feet. The 1.6 W/kg limit applies for most of RIM OEM integrators.

The limit for MPE is 0.6 mW/cm2 at 900 MHz.

Guidelines

RF exposure distance is based on normal operating proximity to the user’s

body. This distance is measured from the feed point of the antenna to the

closest body part. A test need to be performed to determine the passing distance

that meets the exposure limits.

Operating manual compliance statement

The integrator should include a statement in their operation/user/installation

manual making the user aware of RF exposure issues and insuring that the

users keep a passing distance from the antenna while transmitting.

Also the integrator should provide instructions or diagrams in the manual for

proper antenna mounting and position, when applicable, to ensure a safe

exposure distance to the operator and nearby persons.

Introduction – FCC radio frequency exposure rules 7

RIM 902M OEM Radio Modem – Integrator’s Guide

Label

If the final device configuration cannot be controlled so as to limit the user

distance to the antenna then the device needs to have an RF radiation hazard

label warning the user to keep away from the antenna by the specified distance.



2. Getting started

RIM is committed to facilitating the integration of the RIM 902M OEM radio

modem. We provide the necessary resources to evaluate the feasibility of

implementing a wireless communication solution, and work closely with our

partners to develop an application in the shortest time possible.

Years of intense R&D have spawned several tools that have been used

internally to help streamline our own development process. We have included

many of these tools with the RIM 902M OEM Developer’s Kit. The purpose of

the Kit is to accelerate radio integration and to help system designers evaluate

the RIM 902M. Using the Kit, you can quickly begin interfacing the radio

modem to your computing device.

We’re here for you!

RIM has a team of experienced engineers who can support you in the design

and implementation of your project. If you need help getting started, or if you

have any questions about the radio technology or its integration into your

platform, please contact the RIM 902M engineering development team:

e-mail: rim902m@rim.net

phone: +1 (519) 888-7465

fax: +1 (519) 888-7884

web: www.rim.net

10 Getting started – Test board overview

Integrator’s Guide – RIM 902M OEM Radio Modem

Test board overview

The RIM test board provides a standard RS-232 serial interface between a PC

and the radio modem. It is designed to help you quickly interface the

RIM 902M to a standard PC (through a COM port) or a terminal device with

an RS-232 serial port. The test board also provides access points to the radio’s

serial communication port, which allows you to monitor activity with a logic

probe, multimeter, or oscilloscope.

The test board includes the following components and functionality:

RS-232 interface

The serial (COM) port on a PC and most terminal devices operates at RS-232

signal levels, which are typically 12V. This high voltage would damage the

RIM 902M, which is typically integrated into a device that operates an

asynchronous serial port at 3.0V. The RS-232 interface on the test board allows

you to produce an output from the radio that is easily interpreted by a PC.

Test points

The test board is more than just an RS-232 interface. It also features debugging

facilities to help you test your application. It provides direct access to each of

the 22 pins on the serial data cable, which allows connectivity to analytical

equipment (e.g. logic probe, multimeter, or oscilloscope) and real-time

indication of data flow.

On/off switch

With the switch in the ON position, the radio will turn on whenever power is

applied to the test board. When the switch is moved to the OFF position, the

radio will shut down.

Power supply

The RIM 902M must be provided with a clean, high-current power source. In

this case, we use a standard plug-pack to provide the current necessary to

Getting started – How to connect the test board 11

RIM 902M OEM Radio Modem – Integrator’s Guide

operate the radio. The voltage is converted into the necessary levels by the

power supply section on the test board.

LED indicators

The test board includes several LED indicators designed to indicate the flow of

data to and from the host (in real time), the radio power status, power to the test

board, and more.

How to connect the test board

Now that you are familiar with the components and functions of the test board,

you are ready to connect the RIM 902M radio modem to an antenna and to a

PC (or some other computing device with an RS-232 serial interface). To do

this, you will use the test board and cables supplied with your RIM 902M

Developer’s Kit.

1. Flat serial cable (test board to radio)

The flat serial interface cable carries data between the test board and the

RIM 902M. Control and status signals such as TURNON are also carried on

this cable. Use this cable to connect the RIM 902M’s serial connector to the test

board.

This cable also carries clean, regulated power to the RIM 902M.

When inserting the cable, ensure that the side with the bare pins are in direct

contact with the pin side of the connector.

2. DB-9 serial cable (test board to PC)

Connect the male end of the straight-through DB-9 serial cable to the test

board.

Connect the female end of the cable to your PC’s COM port.

12 Getting started – The MENU diagnostics tool

Integrator’s Guide – RIM 902M OEM Radio Modem

3. Power adapter (test board to AC outlet)

Plug the 120VAC-to-12VDC power adapter into the wall outlet. Connect the

other end to the power jack of the test board.

4. Antenna cable (radio to magmount antenna)

Your developer’s kit includes a high-performance, 6dB-gain magmount

antenna. This antenna is terminated with a screw-on SMA plug. The

RIM 902M radio modem includes a snap-on MMCX jack. The antenna cable

supplied with your developer’s kit connects the antenna’s SMA plug to the

radio’s MMCX jack.

The magmount antenna provides the best RF performance when placed on a

broad metal surface, such as the roof of a car. When used inside a building,

performance is improved if the antenna is located near a window, with few

obstacles (wall, furniture, equipment, etc.) between the antenna and the

window. The antenna performs equally well if it is positioned upside down.

5. Turn the system on

The power switch on the test board is connected to the TURNON line of the

RIM 902M radio modem. To determine whether the radio is on, look at the

LED marked ONI. It is lit when the radio is on.

The MENU diagnostics tool

Now that you have successfully connected your RIM 902M radio modem to

your PC, you are ready to send a test packet through the Mobitex network.

Your radio modem should be activated by the network operator in order to be

used on the Mobitex network and to establish an airtime agreement. If you have

not already arranged for activation of your radio, contact your network

operator.

Getting started – The MENU diagnostics tool 13

RIM 902M OEM Radio Modem – Integrator’s Guide

The RIM 902M contains a diagnostic utility called MENU. With this utility,

you can set the current network, “ping” your radio modem, or view radio and

network status values.

Setup

The following instructions assume that your RIM 902M is connected to a PC

running a terminal program, such as Windows HyperTerminal. The MENU

utility is based in the RIM 902M’s firmware, so HyperTerminal is the only

software required to use it.

The MENU utility’s user interface is a full-screen text mode interface, and uses

the ANSI cursor command set. Programs like HyperTerminal support the ANSI

codes by default. If you are using a different terminal program that does not

provide ANSI cursor control, the MENU utility will drop into a line-by-line

interface. The appearance of the line-by-line interface is not documented here,

but the commands it uses are the same as those described below.

Select the COM port which communicates with the RIM 902M and configure

for 9600 bps, and either 7E1 (7 bits, Even parity, 1 stop bit) or 8N1 (8 bits, No

parity, 1 stop bit). If you have set this up correctly, you will see bursts of

characters from the radio modem such as ^0010B 47E,0:5D. These character

bursts are normal; the represent a MASC B frame, which you can ignore for

now.

Type the word menu (all in lower case letters only) then press the ENTER key.

You can expect to see a full screen of information. If nothing happens, simply

re-enter menu until the radio modem responds. The word “menu” itself will

probably not appear on the screen as you type it in.

If you re-enter menu and nothing occurs, ensure that the radio is turned on and

connected to the PC, and that all cables are securely connected. Please contact

RIM for assistance if you are stuck at this point.

Once the utility has been started, the terminal program’s screen will look

similar to the following:

14 Getting started – The MENU diagnostics tool

Integrator’s Guide – RIM 902M OEM Radio Modem

RIM 902M Firmware Version 1.0.0

Radio Setup Radio Serial Number = 031/11/066300

Command Key Description Networks Available:

----------- ----------- -------------------

Q Quit and reset the radio. 1. RMDUS (B433/B433)

2. CANTEL (C4D7/C4D7)

N Set the current network.

P Ping: Send a Status MPAK to yourself.

Your Choice ?

MAN=16231144 RSSI= 40% 24 dBuV Battery= 97% Network=RMDUS (B433/B433)

Contact=Yes Mode=PowerSave Live Tx=Enabled Active=Yes Group List=Born

UpFreq=02FF DoFreq=0F2F Base/Area=14/0A Status=0080

The screen displays the software version and build date, the radio modem’s

serial number, the list of available Mobitex radio networks, current radio

modem status indicators, the “ping” function, and other relevant information.

RSSI stands for Received Signal Strength Indicator. This is a measure of

network coverage. The higher the number, the better the coverage. The RSSI is

given both as a percentage and in dB V (decibel microvolts). To obtain the

RSSI in dBm (decibel milliwatts), subtract 113 from the dB V value. Note that

RSSI= 0% 0 dB V does not necessarily represent the complete absence of a

signal; in many cases, the radio is capable of communicating with the network

at signal strengths of 0 dB V or even less. Actual contact with the Mobitex

network would be indicated by the Contact field. The RSSI is updated every

ten seconds, or whenever you press D.

The Battery indicator shows the level of supplied voltage. The battery level is

updated once every thirty seconds, or whenever you press D.

Network tells you which network you are currently using. The example shows

RMDUS (BellSouth Wireless Data, formerly RAM Mobile Data, operates a

Mobitex network in the United States) and CANTEL (Cantel AT&T operates a

Mobitex network in Canada).

MAN stands for Mobitex Access Number, which is a unique number that

identifies each Mobitex radio modem. The MAN is used for addressing packets.

The screen will also display a Radio Serial Number, which is unique to each

Getting started – The MENU diagnostics tool 15

RIM 902M OEM Radio Modem – Integrator’s Guide

radio modem. This number is often referred to in other documents as ESN

(Electronic Serial Number) or MSN (Mobitex Serial Number).

Mode shows whether the radio is in powersave mode or express mode. The

default operating mode is powersave, which reduces power consumption by the

radio but introduces a latency of up to 10 seconds when receiving packets from

the network. This mode may be changed through software.

Tx is an indicator to let you know whether the radio’s transmitter is enabled or

disabled. The transmitter may be enabled or disabled through software, and is

normally enabled. The Mobitex base station may also instruct a radio to shut

down (also referred to as DIE) if it is an illegal device, or not registered, or

causing disruption to the Mobitex network. The word Live on the status line

indicates that the radio is not in a DIE state.

A radio modem receives a Group List when it is powered up and registers with

the network base station. Normally, you would see Group List=OK, which

indicates that the radio has successfully signed onto a base station. If you see

Group List=Born, then either your device is out of coverage, or it has not been

activated by your network operator. Note that it can take 30 seconds for a radio

to display Group List=OK.

UpFreq and DoFreq show the channels (in hexadecimal) that you are using to

transmit and receive, respectively. If you are interested in obtaining the exact

current transmit frequency, divide UpFreq by 80 and add to 890. This gives a

value in MHz. Add 39 MHz to obtain the receive channel. For example, if the

display reads “UpFreq=02FF DoFreq=0F2F” then convert hexadecimal 02FF to

decimal 767, divide by 80 and add to 890, and obtain 899.5875 MHz, which is

the transmit channel. Add 39 MHz (or repeat the calculation using DoFreq) to

determine that the receive channel at 938.5875 MHz.

Base/Area indicate which base station you are using. Every base station in the

network is assigned a unique Base/Area combination. Base stations in the same

geographic area often share an Area address. Contact your network operator if

you want to know the location of network base stations.

Status describes the current state of the radio. Other documentation may also

refer to the Status value as the radio’s internal fault bits. The following table

shows the interpretation of the Status bits. If the Status value displayed on your

screen does not correspond to any of the values below, then determine which

values add together in hexadecimal to give the Status value that you see. For

example, status value B403 would simultaneously describe states A000, 1000,

0400, 0001, and 0002, as described below.

16 Getting started – The MENU diagnostics tool

Integrator’s Guide – RIM 902M OEM Radio Modem

0000 The radio modem status is normal. There are no warnings.

0001 The RIM 902M has been out of coverage for a long time. No adequate base

station was found. Possible causes include lack of network coverage, wrong

network selected, or the battery level is too low.

0002 This is a new RIM 902M being used for the first time. No action is necessary.

0008 The radio modem has exhausted its internal memory. This should not happen

under ordinary use. Turning the radio modem off and back on will resolve this.

0020 The network has issued a DIE command to the radio modem, perhaps because

it is not registered on the network. No data can be sent to the network until a

LIVE command is issued by the network. Contact the network operator for

help.

0040 The modem’s transmitter has been disabled by your software, using either the

MASC “F M0” or RAP “Turn Transmitter Off” command. The transmitter can

be turned back on with the MASC “F M1” or RAP “Turn Transmitter On”

command, or by resetting the radio.

0080 The radio modem has not yet received a grouplist from the network. If this bit

remains set after the modem has been in network coverage for several minutes,

your radio modem is probably not activated. Contact the network operator to

activate your device.

0100 Another device may be using the same MAN number as your device on the

same base station. This should not happen under ordinary use. It may cause

duplicate, dropped, or mixed up packets. Contact the network operator to

determine whether two units have the same MAN number.

0800 The RIM 902M may be having a problem remembering its last base station. If

the problem persists, the unit should be returned for repair.

1000 The RIM 902M has received an unknown interrupt and might be having

problems receiving packets. If the problem persists, the unit should be returned

for repair.

2000 The RIM 902M has received an unknown interrupt. No action is necessary.

4000 The RIM 902M has been damaged and cannot be used until this problem is

corrected. The unit should be returned for repair.

How to change to a different network

The RIM 902M radio may be used on different Mobitex networks operating on

different channels in the 900 MHz range. Up to 16 network channel lists may

be programmed by RIM into each radio. If the network shown is not the correct

one, you can choose another from the list of networks available. Press N and

the MENU utility will present an additional prompt for selecting the network,

as shown below.

Getting started – The MENU diagnostics tool 17

RIM 902M OEM Radio Modem – Integrator’s Guide

RIM 902M Firmware Version 1.0.0 release

Radio Setup Radio Serial Number = 031/11/066300

Command Key Description Networks Available:

----------- ----------- -------------------

Q Quit and reset the radio. 1. RMDUS (B433/B433)

2. CANTEL (C4D7/C4D7)

N Set the current network.

P Ping: Send a Status MPAK to yourself.

Your Choice ? Choose a network from the list (1..2) ?

MAN=16231144 RSSI= 30% 22 dBuV Battery= 97% Network=RMDUS (B433/B433)

Contact=Yes Mode=PowerSave Live Tx=Enabled Active=Yes Group List=Born

UpFreq=02FF DoFreq=0F2F Base/Area=14/0A Status=0080

Change network name

You may now enter a number corresponding to the desired network shown

under Networks Available. When you press Enter, the radio modem will switch

to the selected network, as shown below. If you do not enter a number, or if you

erase the number you have typed, then no change will occur when you press the

Enter key. Pressing the Esc key will cancel the network set-up command.

The screen below shows what would happen if you typed in 2 and then pressed

the Enter key. The values shown beside Network, UpFreq, DoFreq, and

Base/Area are different.

18 Getting started – The MENU diagnostics tool

Integrator’s Guide – RIM 902M OEM Radio Modem

RIM 902M Firmware Version 1.0.0

Radio Setup Radio Serial Number = 031/11/066300

Command Key Description Networks Available:

----------- ----------- -------------------

Q Quit and reset the radio. 1. RMDUS (B433/B433)

2. CANTEL (C4D7/C4D7)

N Set the current network.

P Ping: Send a Status MPAK to yourself.

Your Choice ?

MAN=16231144 RSSI= 45% 25 dBuV Battery= 97% Network=CANTEL (C4D7/C4D7)

Contact=Yes Mode=Fallback Live Tx=Enabled Active=No Group List=Born

UpFreq=030D DoFreq=0F3D Base/Area=1B/09 Status=0080

Radio update was successful.

“Ping” the network: an end-to-end radio test

You can determine whether your radio modem is working on the network by

pressing P. When you “ping,” you send a message (MPAK – Mobitex data

packet) to yourself via the wireless network base station. The MENU utility will

display a message indicating that the MPAK was sent. A few seconds later, it

should also indicate that the MPAK was received. This confirms that your radio

modem is operational and active on the network.

If you get the message “Status MPAK cannot be sent – out of coverage”, then

you are not in an area that is covered by the Mobitex network. You can

determine whether you are in coverage by looking at Contact on the status

lines. If you are certain that you are in a coverage area, but are still not able to

communicate with the network, check the antenna to make sure it is connected

properly and is deployed properly. Signal quality can vary significantly within a

building. Try moving the antenna to a new location, perhaps near a window, to

see if you can get a signal.

If you get the message indicating that the Status MPAK was sent, but you did

not get one that it was received, then you are in coverage but your RIM 902M

radio modem has probably not been activated by your network operator, and the

network will not send the MPAK back to the radio. Contact the network

operator to activate your design.

Getting started – The MENU diagnostics tool 19

RIM 902M OEM Radio Modem – Integrator’s Guide

RIM 902M Firmware Version 1.0.0

Radio Setup Radio Serial Number = 031/11/066383

Command Key Description Networks Available:

----------- ----------- -------------------

Q Quit and reset the radio. 1. RMDUS (B433/B433)

2. CANTEL (C4D7/C4D7)

N Set the current network.

P Ping: Send a Status MPAK to yourself.

Your Choice ?

MAN=16231227 RSSI= 11% 14 dBuV Battery=100% Network=RMDUS (B433/B433)

Contact=Yes Mode=PowerSave Live Tx=Enabled Active=Yes Group List=Born

UpFreq=02FF DoFreq=0F2F Base/Area=14/0A Status=0080

Received MPAK from 16231227 (to 16231227) Type=03(STATUS ) Traffic/Flags=00

If you are unable to communicate with the network, then contact the network

operator to make sure that your device is activated on the network. If the radio

has not been activated, then the network will not send the MPAK back to the

radio. Second, make sure that you are in network coverage. You can determine

whether you are in coverage by looking at Contact on the status lines. If it

shows Contact=NO, then you are not in an area that is covered by your Mobitex

network. You can also determine whether the antenna is connected properly

and is deployed properly. Signal quality in buildings can vary significantly over

short distances. Try moving the antenna to a new location, perhaps near a

window, to see if you can get a signal. If none of these remedies help, contact

RIM for assistance.

Exiting the utility

When you have finished using the utility, you should press Q to quit. This step

is important because it allows the radio to resume accepting commands from

other software. The screen will clear and you will be informed that the radio

has been reset. You can safely disconnect the radio and close your terminal

program once you have seen this message.



3. Mechanical

integration

This chapter provides information about the RIM 902M that will be useful in

determining the physical positioning of the radio modem within an application.

Environmental properties and testing, physical properties, mounting methods,

and connector information are presented.

Environmental properties

During environmental testing, RIM takes samples of its radio modems and

subjects them to a variety of harsh conditions. We measure over a hundred

digital RF calibration parameters, once before and once after each test. The

difference between these measurements precisely reveal any performance

degradation. Each unit in the sample is also inspected visually after testing.

This experience allows us to fine-tune our design and manufacturing process.

Environmental testing ensures that our products are able to withstand both

typical and extreme real-world conditions in which they will be used. RIM does

not sell units that have been subject to environmental testing.

22 Mechanical integration: Physical properties

Integrator’s Guide – RIM 902M OEM Radio Modem

Storage temperature

The RIM 902M OEM radio modem may be stored at a temperature from -40 C

to +85 C (-40 F to +185 F).

Operating temperature

The RIM 902M is designed to operate between -30 C to +70 C (-22 F to

+168 F).

The end user should be careful not to exceed the upper temperature limit of

+70 C, as performance degradation or damage to the power amplifier may

occur past this point, especially when packets are transmitted frequently.

Physical properties

Weight

The RIM 902M weighs 1.2 oz (35 g), including the case.

Dimensions

The RIM 902M has been designed to meet the most stringent space

requirements. In most cases, there will be sufficient room in an existing

enclosure to house the radio modem.

The overall maximum dimensions of the radio modem, not including cables,

are:

Width: 42.0 mm

Length: 67.5 mm

Thickness: 8.4 mm

Mechanical integration: Physical properties 23

RIM 902M OEM Radio Modem – Integrator’s Guide

24 Mechanical integration: Mounting methods

Integrator’s Guide – RIM 902M OEM Radio Modem

Mounting methods

The RIM 902M OEM radio modem may be securely fastened using a variety of

methods. The operating environment must be carefully considered when

choosing a mounting option. For example, extreme temperature or heavy

vibration may require a special mounting solution. It is important to ensure that

the RIM 902M remains securely attached in the environment where it will be

used.

The following information is presented as a guide, but applications can vary

considerably. A mechanical engineer can help ensure that the mounting method

is suitable for the specific application.

Bolts

The RIM 902M radio modem includes a hole in each corner, which may be

used to bolt the device onto a circuit board, device housing, or other surface.

The mounting hole pattern is four holes in a 62.5 by 36.5 mm rectangle, with

each hole 2.5 mm in diameter.

The following diagram illustrates the radio mounting details.

Mechanical integration: Mounting methods 25

RIM 902M OEM Radio Modem – Integrator’s Guide

Tie wraps

Tie wraps can be used to as a secure but non-permanent means of attaching the

RIM 902M to a surface. Typically, each tie wrap passes through a hole drilled

26 Mechanical integration: Mounting methods

Integrator’s Guide – RIM 902M OEM Radio Modem

into the surface on either side of the RIM 902M. This allows the radio to be

attached to a shell, a PCB, or some other mounting surface.

If using tie wraps, ensure that the surface beneath the RIM 902M is flat.

Otherwise, the mounting surface could push up on the bottom surface of the

radio case while tightening the tie wraps pushes down on the edge of the radio

case. This could cause the metal case of the RIM 902M to flex upward and

short across components inside the radio, causing the radio to malfunction. For

example, thick adhesive foam tape and tie wraps should not be used together.

Permanent industrial adhesive

The RIM 902M is small and lightweight enough to be attached to the host

device using an industrial adhesive. For some applications, this method of

mounting is preferable to bolts, because adhesive is easier to use in a

manufacturing environment, and is more resistant than bolts to loosening. In

many cases, an effective solution is to adhere the radio modem to the inside

surface of your product’s casing.

An adhesive should be chosen on the basis of its ability to stick to the material

used in the outer casing of the radio modem and in the surface to which the

radio will be mounted. The bottom casing of the RIM 902M is magnesium.

3M manufactures VHB, a permanent industrial adhesive with excellent long-

term holding power. The peel adhesion and tensile holding power of VHB tapes

are extremely high, making this a suitable solution when the radio will not

need to be removed. Choose foam tape for rough surfaces and adhesive tape for

smooth surfaces.

More information about VHB may be obtained by contacting 3M Industrial

Tape and Specialties Division at 1-800-227-5085 (fax: 1-612-733-1771). The

publication number for the VHB technical data sheet is 70-0702-0266-

1(104.5)R1.

Mechanical integration: Cables and connectors 27

RIM 902M OEM Radio Modem – Integrator’s Guide

Cables and connectors

There are two connectors on the RIM 902M radio modem. These connectors

allow interfacing from the radio modem to a serial computing device, a power

supply, and an antenna.

Serial cable and connector

The RIM 902M serial communication and control signals are carried on a flat

22-conductor 0.30 mm (0.012”) thick flexible printed circuit (FPC) cable in

1.00 mm centerline spacing, which can plug into a matching connector. Since

each application is unique, Molex can create a custom Flat Flex Cable Jumper

in the correct length and the correct connector orientation for your application.

The minimum cable length available is 30 mm (1.181”).

The serial cable supplied with the RIM 902M Developer’s Kit is a Type D 4”

long Flat Flex Cable Jumper in 1.00 mm centerline spacing, as illustrated in

the following mechanical drawing:

28 Mechanical integration: Cables and connectors

Integrator’s Guide – RIM 902M OEM Radio Modem

This cable can plug into a matching 22-position 1.0 [0.039] horizontal FPC

connector. A variety of connectors are manufactured by Molex. More

information about each connector, including mechanical drawings, is available

from the manufacturer’s web site (www.molex.com), or you can contact RIM

(rim902m@rim.net) for help with selecting an appropriate connector for your

application.

Contact:

Molex Headquarters Molex Electronics Ltd.

Lisle, IL, USA Toronto, Ontario, Canada

tel: (630) 969-4550 tel: (416) 292-1444

fax: (630) 969-1352 fax: (416) 292-2922

www.molex.com

Antenna cable and connectors

RIM selected the industry-standard MMCX connector for the RIM 902M

because it is a very small connector that has the mating force to withstand

heavy vibration.

Typically, an antenna does not plug directly into a RIM 902M. Instead, an

connector at the outer casing of the device. This allows the antenna to be

removed from the system without having to open the device, and it eliminates a

source of strain on the radio’s MMCX connector.

The antenna cable should have low loss, an impedance of 50 , and an MMCX

jack that mates with the RIM 902M’s MMCX plug. The other end of the cable

can be any connector you choose, as long as it has an impedance of 50 . An

SMA screw-on connector is suitable and widely available. TNC connectors are

also suitable, but larger than SMA. The antenna cable supplied with the

RIM 902M developer’s kit has an MMCX connector on one end and an SMA

connector on the other. The cable is built with strain reliefs to prevent damage.

Huber & Suhner can provide antenna cables and connectors. The parts

described below have an impedance of 50 and are suitable for use with the

RIM 902M.

Mechanical integration: Cables and connectors 29

RIM 902M OEM Radio Modem – Integrator’s Guide

11MMCX-50-2-1C/111 Straight MMCX connector

16MMCX-50-2-1C/111 Right-angle MMCX connector

25SMA-50-2-25/111 SMA connector

EZ Flex 405 Low-loss matching (50 ) cable

133REEZ4-12-S2/1216 8” cable, straight MMCX to SMA

133REEZ4-12-S2/1699 8” cable, right-angle MMCX to SMA

The following cable is included with the RIM 902M Developer’s Kit:

Contact:

Huber & Suhner Huber & Suhner

Essex Junction, VT, USA Kanata, Ontario, Canada

tel: (802) 878-0555 tel: (800) 627-2212

fax: (802) 878-9880 fax: (613) 596-3001

www.hubersuhnerinc.com



4. Power requirements

The RIM 902M radio modem must be provided with a clean power source

capable of delivering bursts of high current. This can be provided by a plug-in

power supply unit, a rechargeable battery pack, or single use batteries. RIM has

conducted extensive research and has developed guidelines for integrators to

follow when designing the power supply system for the RIM 902M.

Load specifications

The RIM 902M draws its power in bursts; the power required changes rapidly

depending on whether the radio is transmitting, receiving, or in standby. The

load profile is given on the following page. These specifications can be given

directly to your power supply designer or battery supplier.

Power supply parameters

The RIM 902M requires a clean, stable 4.15 to 4.75 volt source that is capable

of delivering a one-second burst of up to 1.7A when required by the transmitter.

Under non-ideal conditions such as an improperly matched antenna, however,

this burst could be as high as 2.2A. The receiver current consumption is 66 mA

and the standby current consumption is 0.07 to 0.2 mA. The maximum no-load

32 Power requirements: Batteries

Integrator’s Guide – RIM 902M OEM Radio Modem

Radio load profile (at 4.5V)

Transmitter ON

at 2.00 W to antenna

worst-case peak instantaneous (due to extreme

temperature, poorly matched antenna, etc.)

1.7 A

2.2 A

Receiver ON

In EXPRESS mode, the receiver is always ON.

In POWERSAVE mode, the receiver is typically

ON for 0.15 s then OFF for 9.85 s

57 mA

Standby (transmitter and receiver are both OFF)

Standby mode occurs for 9.85 s out of 10 s if in

POWERSAVE mode and no activity has taken

place for previous 10 s

0.2 mA

5.4 mA

Typical average power-save current consumption

transmit 0.17%, receive 9.74%, standby 90.09%

transmit 1%, receive 5%, standby 94% 5.7 mA

20.0 mA

Transmit duration

minimum

maximum 32 ms

1 s

Off current consumption 20 A

Batteries

When integrated into a handheld device, the RIM 902M can be powered by

batteries. This is a proven technology that is easily available and eliminates the

need for power supply components such as voltage regulators.

Rechargeable batteries

We recommend using rechargeable nickel cadmium (NiCad) batteries to power

vthe RIM 902M radio modem for battery-operated applications that require a

wide operating temperature range. Nickel metal hydride (NiMH) and Lithium

ion (Li+) cells may also be used with good results, but many such cells do not

work very well at temperatures below freezing. Specifications for batteries

Power requirements: Batteries 33

RIM 902M OEM Radio Modem – Integrator’s Guide

should be obtained from the manufacturer. The RIM engineering development

team can help you determine whether a particular battery is suitable for your

application.

The cells chosen must be able to meet the load specifications of the RIM 902M.

Specifically, they must be able to provide 1.7 A (at 4.5V) for transmission.

Rechargeable cells vary considerably, because capacity varies with current

draw. Even if two cells have the same published capacity, one may not be as

efficient as another when the radio transmitter is turned on. This is because

some batteries have a higher equivalent series resistance (ESR) at high current

drain. The ESR should be low enough that the battery can supply the transmit

current required without a large voltage drop.

Rechargeable alkaline batteries are another option. These cells are typically

rated for about 25 discharge cycles, far fewer than NiCads, but they provide

longer life than NiCads. For the first five to ten cycles, you will get about 70 to

80 percent of the battery life you would expect from a single-use alkaline cell.

After 25 discharges, this number may drop to 50 percent. Some precautions

must be taken with this type of battery. These cells are also not intended to be

used to their full capacity, so the actual useful run-time of these cells is closer to

30 to 40 percent of a single-use alkaline cell, and requires the user to pay closer

attention to the state of the batteries. If you fully discharge a rechargeable

alkaline battery, you may only get five recharges before the capacity decreases

to the point where it is useless.

Single-use batteries

Among single-use cells, only alkaline and lithium cells provide the high

current necessary for transmission. In particular, alkaline AA’s are

inexpensive, widely available, and provide an excellent power source. Alkaline

cells typically run about four times longer than similar-size NiCad cells, and

about three times longer than similar-size NiMH cells.

The use of general-purpose carbon-based batteries is not recommended, as this

type of battery is unable to supply the power required by the transmitter. If this

type of battery is used, the voltage will drop below the minimum power

required under load almost immediately following a radio transmit, which

would reset the radio.

Since carbon cells are generally sold under names like “super heavy duty,” the

best way to be sure that a single-use battery is alkaline is to look for the word

34 Power requirements: Plug-in supplies

Integrator’s Guide – RIM 902M OEM Radio Modem

“alkaline” on the label, or to use well-known brands such as Duracell or

Energizer. This should be communicated to the user of your product.

Plug-in supplies

A plug-in supply converts normal AC power (usually 110 volts or 220 volts)

into a steady DC source that can be used instead of batteries. The plug-in

supply must be designed to ensure voltage spikes, lightning, and other power

fluctuations cannot damage the radio modem. Transient voltage protection

zener diodes, or other spike arrestor circuits, may be added to keep the inputs

within the limits given in the RIM 902M load specifications. These should have

a value of 20 volts and be placed on the supply side of the regulator circuit.

RIM recommends a supply capable of providing 4.5 V and rated for 2.5 A peak

current.

Automotive supplies

If you plan to power the RIM 902M from an automotive supply, extra

protection must be included to protect the radio modem from the intense power

fluctuations experienced when the automobile is started. A circuit comprising

inductors, transorbs and voltage regulators should be used to ensure the radio

modem is protected from these power fluctuations.

Commonly, in automotive applications, voltages may be as high as 70 V on the

battery, especially during starting. Commercial automotive adapters are

available that will safely convert the 12 volt automotive supply to a regulated

supply suitable for operating the RIM 902M radio modem.



5. Interface

specification

The asynchronous serial interface on the RIM 902M operates at 3.0V. It is

similar to RS-232 except that 0V represents a “low” and 3V represents a

“high.” This interface can be connected directly to a micro-controller, or

through a UART to a microprocessor data bus.

MASC and RAP link-layer protocols

The RIM 902M requires a serial link-layer protocol to carry data, radio control

instructions, and radio status information between the RIM 902M radio modem

and the computing device to which it is attached. Two protocols are supported:

Mobitex Asynchronous Communication (MASC) and Radio Access Protocol

(RAP).

If you are using a MASC application with another Mobitex radio and are now

migrating to the RIM 902M, you do not need to rewrite the application in RAP

– simply continue using the MASC application. If you are writing a new

application for the RIM 902M, you will need to choose whether to use MASC

or RAP as your link-layer protocol.

MASC assumes a high-noise environment where bit errors are likely to occur

on the serial link between the radio modem and the computing device. MASC

36 Interface specification: MASC and RAP link-layer protocols

Integrator’s Guide – RIM 902M OEM Radio Modem

is designed to be extremely robust and redundant, and should be used when the

serial link is unreliable or when the serial cable to the RIM 902M is very long.

Advances in mobile computing technology have helped to ensure that serial

links are short enough to make bit errors extremely unlikely. This is especially

true for smaller devices such as laptops and PDAs. The complexity of MASC is

unnecessary for these applications, and involves complex and lengthy software

development.

RAP was designed to take advantage of the reliability inherent to a short serial

link. The primary benefit of RAP is that it is easy to describe and implement.

As a result, RAP reduces software development time, complexity, and memory

consumption. It also provides double the throughput of MASC, by using binary

frame data transfers instead of hex-ASCII encoding.

Since every application is different, the choice of protocol should be made

carefully. The following chart is provided as a guide to comparing the relative

advantage of each protocol.

MASC RAP

Serial cable between

RIM 902M and device Designed for long serial

cable prone to bit errors Assumes a short, reliable

serial cable

Operating environment Withstands harsh, hostile

electrical interference Best suited for laptops,

PDAs, other small devices

Software complexity Complex Simple

Implementation time

(typical) Weeks or months,

or use third-party API’s Days

Memory requirements 10 to 50 kilobytes 1 to 3 kilobytes

Hardware flow control RTS/CTS is required RTS/CTS is optional

Throughput at 9600 bps 4800 bps 9600 bps

Cost Free, open specification,

or pay for third-party API’s Free, open specification,

sample source code is free

Interface specification: Pin descriptions 37

RIM 902M OEM Radio Modem – Integrator’s Guide

There is no “best” protocol. The MASC or RAP protocol is used strictly for the

link between the radio modem and the computing device, and does not have

any influence on the speed or reliability of communication between the radio

and the Mobitex network. The RIM engineering development team (e-mail:

rim900@rim.net) can help you select the protocol most suited to your needs.

Pin descriptions

All input and output lines are 3.0 volt logic; however, they will also be able to

drive 3.3 volt systems. Further, all input lines to the serial port are 5.0 volt

tolerant and outputs will be capable of driving 5.0 volt systems provided the VIH

of these pins is less than 2.5 volts. Pins 1 through 4, the general purpose I/O

lines, are strictly a 3.0 volt interface; they are not 5.0 volt tolerant.

This section describes the purpose of each of the 22 lines that comprise the

serial interface of the RIM 900 OEM radio modem. The symbol ~ before the

label indicates that line is an active low digital signal.

Pins 1, 2, 3, 4, 13, and 22 are designed for future use and must be left

disconnected. All other unused inputs to the radio should be tied to ground, and

any unused outputs from the radio should be left disconnected.

Pin 5 ~MSG ~Message Waiting

This is an output from the radio.

The active state of this line is low, and indicates that the radio has received a

message (packet) from the network, which has not been delivered to the device

application yet. This line continues to remain active until the application

acknowledges receiving the packet.

When the radio’s receive buffer is full, this line will be inactive (high).

38 Interface specification: Pin descriptions

Integrator’s Guide – RIM 902M OEM Radio Modem

Pin 6 ~COV ~Coverage

This is an output from the radio.

The active state of this line is low, and indicates that the radio is in network

coverage, as measured by the presence of a signal from the network base

station.

When the radio does not have contact with the wireless network, this line is

high.

Pin 9 GND Ground

This line should be tied to the system ground of the host unit to ensure proper

operation.

Pin 10 TURNON Turn Radio On

This is an input to the radio.

This line turns on the radio unit. It is a digital signal that eliminates the need

for an on/off switch across the power supply to the radio. Information about the

use of this pin is contained in the next section of this chapter.

Pin 11 ONI On Indicate

This output from the radio that indicates that the radio is on and operational.

This line may be used by a computing device to qualify the handshaking

outputs on the serial interface. If CTS is low, and ONI is high, then the unit is

ready to receive data, but if CTS is low and ONI is low, then the radio is not

ready to receive data because it is off.

When ONI is low, all inputs to the radio should be held low or disconnected.

Otherwise, power will be consumed and wasted.

Interface specification: Pin descriptions 39

RIM 902M OEM Radio Modem – Integrator’s Guide

Pin 12 TRI Transmit Indicate

The active (radio transmitting) state of this line is high.

This output from the radio that is asserted while the RIM 900 is transmitting a

packet to the network base station. TRI can be used to provide real-time visual

feedback to the user that the radio is transmitting packets. If this is not

necessary, the line can simply be left disconnected.

This line is low when the Radio is off.

Pin 14 ~RI ~Ring Indicate

This is an output from the radio.

When ~DTR is not asserted (high), the RIM 900 asserts ~RI (low) to indicate

that it has data waiting for the computing device. The radio will not transfer the

data until ~DTR is asserted (low). This line can be used to wake up a

suspended computing device when the radio needs to communicate with it. If

~DTR is already asserted (low) when the radio has data to send the computing

device, ~RI will not be asserted.

For MASC implementations in normal serial mode, this line indicates that the

radio has any MASC frame to transfer to the computing device. For MASC

implementations in interactive serial mode, this line indicates that the radio has

received an MPAK from the Mobitex network, and has a MASC M frame

containing the MPAK to transfer to the computing device.

For RAP implementations, ~RI is not used and should not be connected. This

line should also be disconnected if your application does not use it.

Pin 15 ~CTS ~Clear To Send

This line is an output from the radio modem. The active (clear to send) state of

this line is low.

All MASC implementations require this line. This line is optional for RAP

implementations. To use hardware flow control with RAP, the radio must be in

interactive serial mode (see pin 10). Do not connect ~CTS if your application

does not require it.

40 Interface specification: Pin descriptions

Integrator’s Guide – RIM 902M OEM Radio Modem

This is an output from the RIM 900 to the computing device. This line is

asserted low by the RIM 900 to indicate that it is ready to receive data from the

computing device. When this line is high, any data sent from the computing

device to the RIM 900 may be lost. This is a flow control mechanism that is

normally reacted to by the UART in your serial communication system.

When the radio is turned off, this line will be low from inside the radio modem

with an impedance of at least 20 k .

Pin 16 ~RTS ~Request To Send

This line is an input to the radio. Its active (request to send) state of this line is

low.

All MASC implementations require this line. This line is optional for RAP

implementations. Connect ~RTS to ground if your application does not require

it.

This is an input to the RIM 900 from the computing device. This line should be

asserted low by the computing device to indicate that it is ready to receive data

from the RIM 900. This is a flow control mechanism that is normally handled

by the UART in your serial communication system.

Pin 17 ~DSR ~Data Set Ready

This line is an output from the radio.

The active (data set ready) state of this line is low.

When the RIM 900 is off, this line will be low from inside the radio modem

with an impedance of at least 20 k .output from the RIM 900 that indicates the

state of DTR.

Pin 18 GND Ground

This line should be tied to the system ground of the host unit to ensure proper

operation.

Interface specification: Pin descriptions 41

RIM 902M OEM Radio Modem – Integrator’s Guide

Pin 19 ~DTR ~Data Terminal Ready

This line is an input to the radio.

The active (data terminal ready) state of this line is low, and indicates that the

computing device is ready to receive data from the RIM 900. De-asserting this

line high will turn communication off; the RIM 900 would not attempt to

deliver data to the computing device until ~DTR is again asserted low.

Asserting this line low will cause the radio to send a MASC B frame to the

computing device if MASC is the protocol being used, and will allow

communication to resume.

If you do not intend to use ~DTR, tie it to ground to ensure that it is always

asserted during radio operation.

This line should be driven low when the radio is off. Driving ~DTR high when

the radio is off will consume unnecessary power.

Pin 20 TX Transmit

This line is an input to the radio. Its idle (no data) state is high.

This is an asynchronous serial input to the radio unit, and should be connected

to the computing device’s Transmit Data output. This line carries data at 9600

bits per second. MASC parameters are 7 bits, Even parity, 1 stop bit. RAP

parameters are 8 bits, No parity, 1 stop bit.

42 Interface specification: How to turn the radio on and off

Integrator’s Guide – RIM 902M OEM Radio Modem

Pin 21 RX Receive

This is an output from the radio. Its idle (no data) state is high.

This line is an asynchronous serial output from the radio unit, and should be

connected to the host terminal’s Receive Data input. This line carries data at

9600 bits per second. MASC parameters are 7 bits, Even parity, 1 stop bit. RAP

parameters are 8 bits, No parity, 1 stop bit.

How to turn the radio on and off

The TURNON pin is a digital signal that turns the raido on and off. It

eliminates the need for a power switch across the power supply to the radio.

Turning the radio on

To turn the RIM 902M on, the software should first check the ONI pin. If ONI

is high, but TURNON is being held low, then your application has recently

requested the radio to shut down, and the radio is performing shutdown

operations and should not be disturbed. Wait for ONI to go low before

continuing.

If ONI is low, this indicates the radio is turned off. Set the TURNON line high

to turn the radio on. The ONI pin will respond by going high, typically within 2

seconds. Once the ONI pin is high, other handshaking and communication

signals can begin.

If the radio fails to respond to a high TURNON line, the radio may require

service, or the power supplied to the radio may be too low for proper operation.

Turning the radio OFF

To turn the RIM 902M off, your software should de-assert the TURNON line

by setting it low. The radio will then begin shutdown operations, and the ONI

pin will remain active until all shutdown operations are complete.

Interface specification: Interface to an RS-232 device 43

RIM 902M OEM Radio Modem – Integrator’s Guide

Shutdown will normally require several seconds to complete, and the radio

should not be disturbed while it is shutting down. Attempting to communicate

with the radio during shutdown may extend the time taken to perform

shutdown operations. The ONI signal will be de-asserted (low) when the radio

has shut down.

All serial inputs to the radio should be low when the radio is turned off. This

ensures that power consumption will be reduced to the lowest possible levels.

Note that if any line is left in the high state, as much as 5 mA may flow into the

radio modem.

MPAK data that has been received by the RIM 902M from the Mobitex

network, but which has not been transferred to the computing device, will not

be saved. The MPAKs will be lost when the unit enters shutdown or is turned

off.

A controlled shutdown is necessary to allow the RIM 902M to tell the Mobitex

network that it is off air.

Interface to an RS-232 device

The RIM 902M serial interface operates at 3.0V, making it compatible with

many existing system designs. In most cases, the RIM 902M can be connected

directly to a micro-controller without any additional interface logic. If the radio

modem is to be connected directly to a PC or other RS-232 device, an interface

must be provided.

Interface to microprocessor

The RIM 902M can be controlled by a wide variety of microcontrollers and

microprocessors, such as the Intel 8051 or 80386, or Motorola 68000.

A standard 8250 Universal Asynchronous Receiver/Transmitter (UART)

interface may be used as the means for communicating with the

microprocessor’s data bus.

44 Interface specification: Interface to microprocessor

Integrator’s Guide – RIM 902M OEM Radio Modem



6. Antenna selection

The antenna is one of the most important components of a wireless

communication system. The right antenna will maximize the coverage area of

the RIM 902M.

The antenna that you choose should complement the needs of your specific

project. There are many different antenna types and options that will meet your

engineering and user requirements while remaining within budget constraints.

We strongly recommend the use of an experienced antenna provider in order to

realize the highest gain possible. A well-designed antenna solution will

maximize efficiency, coverage area, and battery life.

Selecting an antenna

Antenna manufacturers have designed and manufactured a wide variety of

antennas for use on the Mobitex network, and for other RF systems operating in

the 900 MHz range. RIM does not recommend specific antennas because the

choice of antenna is application dependent.

The performance of an antenna depends on its configuration and environment:

the same antenna will behave differently in one device than in another device,

even if both devices use the same RIM 902M radio modem. For example,

magmount antennas include a magnetic base that allows the antenna to clamp

onto a metal surface. This surface is called a ground plane, and reflects

electromagnetic radiation that would otherwise be lost to the antenna. This

46 Antenna selection: Introduction to antenna terminology

Integrator’s Guide – RIM 902M OEM Radio Modem

effectively doubling the length of the antenna by creating a virtual “mirror

image” of the antenna beneath the plane.

Antenna requirements

The following are the minimum requirements of the antenna system used with

the RIM 902M.

Impedance: 50

Center frequency: 913.5 MHz, 5 MHz ( =32.8 cm, 0.2 cm)

this is deliberately biased toward transmit in order

to help balance the two-way link between the radio

modem and the network base station

Frequencies of operation: 896 to 902M MHz (transmit)

935 to 941 MHz (receive)

Acceptable return loss: VSWR < 2.0 or RL < 10 dB (minimum)

VSWR < 1.5 or RL < 14 dB (recommended)

required across all frequencies of operation

Introduction to antenna terminology

This section introduces some of the terminology that is used to describe

antennas, and expands on the summary of antenna requirements, above.

Gain and ERP

Antennas produce gain by concentrating radiated energy in certain areas, and

radiating less energy in other directions. The amount of gain depends on the

radiation pattern, antenna match, and antenna efficiency. Antenna gain is

given as a rating of the maximum increase in radiated field energy density

relative to an ideal isotropic radiator, expressed in decibels (dB) of power gain.

Interfacing and Controlling the RIM 902MAntenna selection: Introduction to antenna

terminology 47

RIM 902M OEM Radio Modem – Integrator’s Guide

An isotropic radiator a 100% efficient point source radiator with a spherical

radiation pattern. Its field energy density is identical in any direction from the

radiator at each fixed distance from the radiator. An isotropic radiator cannot

exist in practice; it is an unrealisable theoretical reference for measuring

antenna gain and radiation patterns.

The power output of the RIM 902M is 62 mW to 2.0 W at the antenna port, and

the antenna gain (or loss) will result in an increase (or decrease) in this value.

The actual output is called the Effective Radiated Power, or ERP. For example,

if the RIM 902M is putting out 2.0 W of power to a 2.3 dB gain antenna, the

ERP is 2.0 10^(2.3 10) = 3.4 W, the actual power radiated by the antenna in

the direction of maximum gain and polarization.

Impedance matching, return loss, and VSWR

The antenna, cables, and connectors in a radio frequency system must all

possess the same impedance. The impedance required by the RIM 902M is

50 , which is a widely-available industry standard. Any deviation from this

value may result in impedance mismatch.

Impedance mismatch can be caused by cable connections, cable lengths, and

imperfections in the cables and connectors. The mismatch causes some of the

radio frequency energy to be reflected back from the location of the mismatch.

This interferes with the signal and reduces its amplitude, resulting in a power

loss.

Antenna mismatch can be expressed as a return Loss (RL), which is simply the

ratio of reflected power to the incident power, expressed in decibels.

RL 10 10

log P

reflected

output

Equation 1: Return Loss

The Voltage Standing Wave Ratio (VSWR) is another way of expressing the

ratio of incident power (from the RIM 902M) to reflected power (into the

RIM 902M).

48 Antenna selection: Introduction to antenna terminology

Integrator’s Guide – RIM 902M OEM Radio Modem

VSWR

1 - P

reflected

output

reflected

output

Equation 2: VSWR

VSWR = 1 or RL = dB is a perfect match. In practice, there will always be

imperfections, which means that VSWR will be greater than 1 and RL will be a

negative number.

VSWR and RL normally vary as a function of frequency. The RIM 902M’s

frequency range includes 896 to 902M MHz (transmit) and 935 to 941 MHz

(receive). The minimum acceptable match across this range must be

VSWR < 2.0 or RL < 10 dB. For best performance, the recommended antenna

match at these frequencies is VSWR < 1.5 or RL < 14 dB.

Antenna size

The optimal antenna radiation efficiency is produced by an antenna measuring

one wavelength, . The value of for the RIM 902M is 32.8 cm, and is

calculated by dividing the speed of light c = 3 x 108 m/s by the center frequency

f = 913.5 MHz. Because the RIM 902M’s receiver is so sensitive, this value

includes a 5 MHz bias toward the transmit frequencies to help balance the

uplink and downlink between the radio modem and the network base station.

Antenna lengths of /2, /4, and /8 also work well, and usually result in a

relatively well matched antenna. /2 or /4 can be electrically “shortened” by

adding load matching elements to control the antenna match. However, this

shortening will reduce the antenna efficiency and therefore the effective

radiated power.

Interfacing and Controlling the RIM 902MAntenna selection: Positioning the antenna 49

RIM 902M OEM Radio Modem – Integrator’s Guide

Positioning the antenna

Proper positioning of the antenna will maximize the gain provided by the

antenna. In determining the proper position, the designer must carefully

consider the environment in which the device will be used. Physical devices can

vary significantly, and incorporating the antenna is an integral part of a

successful design.

The Mobitex network is based on vertically polarized radio-frequency

transmission. Therefore, the antenna should ideally be oriented so that it

provides vertical polarization. This is achieved by positioning the antenna

vertically upward when the RIM 902M is in use. In small, hand-held devices, it

may be convenient to design the unit in such a way that the antenna folds out of

the way when not in use.

The antenna should be located as far from the active electronics of the

computing device as possible. In general, metal construction in the case of the

computing device and its internal components may attenuate the signal in

certain directions. This is not desirable, as it would reduce the sensitivity and

transmit performance of the radio modem when the computing device is held or

positioned in certain orientations. However, the judicious use of metal in the

construction of a ground plane for an antenna can significantly improve the

antenna gain and the coverage area of the system.

If the computing device is designed to sit on a surface, then the antenna should

be as far from the bottom of the device as possible. This will reduce RF

reflections whenever the device is placed on a metal surface.

When the computing device is hand-held or is worn next to the body of the

user, the antenna should be positioned to radiate away from the body.

Otherwise, the body will absorb the radiated energy and the effective coverage

area of the radio will be reduced.

For best results, the antenna should be connected directly to the antenna cable.

If an extension cable is required, it should be low loss, as short as possible, and

have an impedance of 50 . It is important that a proper matching connector

be used, as each connector in the signal path introduces a return loss and

reduces performance.

50 Antenna selection: Shielding

Integrator’s Guide – RIM 902M OEM Radio Modem

Shielding

The electrical design of the RIM 902M provides high immunity to RF noise.

The metal casing also acts as a shield to help minimize the effect of RF

interference originating from the computing device to which it is attached, and

to prevent the RIM 902M from emitting RF energy into the computing device

and disrupting the computing device’s operation.

Consequently, you do not need to provide any additional RF shielding between

the RIM 902M and a computing device. In fact, it would be more important for

the power supply to the RIM 902M to be free of high-frequency electrical noise,

than to provide additional RF shielding.

The antenna must be positioned in such a way that the radiated energy is

directed away from the computing device. If this is not possible, then RF

shielding may be required between the antenna and the computing device.

Note that circuits with a high impedance, and sensitive analog circuits, are

especially vulnerable to nearby radio frequency emissions, and may need to be

shielded. Typically affected circuits include CRTs and LCD display drivers.

Specifications

The following is a summary of the RIM 902M OEM radio modem

specifications.

Power supply & typical current usage

Single power supply; operating range: 4.1 to 4.75V DC

Single 3.0V logic line to turn on/off

Typical off current consumption: less than 10 A

Battery save stand-by mode: 0.2 mA (at 4.5V)

Receive / express stand-by mode: 57 mA (at 4.5V)

Transmit mode: up to 1.7A (at 4.5V, output 2.0W)

Average current usage: 20 mA (at 4.5V, based upon 94% standby, 5% receive, 1%

transmit)

RF properties

Transmit frequency: 896 to 902M MHz

2.0 W nominal maximum transmit power at antenna port

Transmitter can reduce output power to 0.06 Watts (-15 dB) when it is close to the

base station, to balance radio link

Receive frequency: 935 to 941 MHz

Receive sensitivity: -118 dBm at 0.01 bit error rate (BER)

8000 bps 0.3 BT GMSK

FCC Parts 15 & 90

Industry Canada RSS 122

Serial communications

3.0V asynchronous serial port

7 bit with parity (MASC) or 8 with no parity (RAP)

Link speed: 9600 bps

Link level protocols:

Radio Access Protocol (RAP)

Mobitex Asynchronous Communication (MASC)

52 Specifications: Shielding

Integrator’s Guide – RIM 902M OEM Radio Modem

Other features

A simple-to-use firmware utility displays serial number, MAN, RSSI level, battery

strength, and network parameters. It can also select different Mobitex networks or

"ping" the network to test the radio modem.

Software can activate radio

Hardware flow control

Radio parameters stored at power down

Terminal devices may power-down while radio-modem remains operational

Certified by RAM Mobile Data to meet Mobitex Interface Specifications (MIS)

including the following features:

Personal subscriptions

ESN verification

Switching between different Mobitex networks

Frame and continuous modes

Mechanical & environmental properties

Weight: 1.2 oz (35 g), including case

Footprint: 42 by 69.5 mm

Thickness: 8.4 mm

3.0V serial connector: 22 pin FPC (Flexible Printed Circuit) connector

Antenna cable connector: MMCX

Tested to IEC 68-2-6 Part 2 for vibration

Metal case, available in a variety of materials

Operating temperature tested to: -30°C to +70°C

(at 5-95% relative humidity, non-condensing)

Storage temperature: -40°C to +85°C

Glossary of terms

Term: Meaning:

c The speed of light.

dB decibel. A measure of power, based on a logarithmic scale.

Embedded System A computer without the normal display, keyboard, and

disk drives of a PC.

FPC Flexible Printed Circuit. The serial communication cable

on the RIM 902M is made using this type of flat multi-

conductor wiring.

Gain In this document, refers to increase/decrease in radiated

power.

MAN Mobitex Access Number. Each Mobitex radio modem has

one unique MAN. A MAN is a 24-bit number. The

network operator will assign a MAN to each radio modem

when they authorize its use on their Mobitex network.

MASC Mobitex Asynchronous Serial Communications. The link

layer protocol exchanged via an asynchronous full-duplex

serial channel between a data terminal or computing

device and the RIM 902M OEM Radio Modem.

MMCX The connector on the RIM 902M to which an antenna

cable is connected.

Mobitex A radio network and its communication protocols, created

by Ericsson and the Swedish Telecommunications

Administration.

MPAK Mobitex Data Packet. A parcel of data transferred

between the Mobitex network and the radio modem.

Network Operator The corporation or agency which installs, maintains and

authorises use of a Mobitex network in a given area,

usually within one country.

Noise Refers to undesired, random interference combining with

the signal. If the device is not immune to noise, the

interference must be overcome with a stronger signal

strength. Noise can be produced by electronic components.

54 Glossary of terms: Shielding

Integrator’s Guide – RIM 902M OEM Radio Modem

Term: Meaning:

OEM Original Equipment Manufacturer. Usually implies that

the “OEM product” is re-labelled with another

manufacturer’s name. The RIM 902M is designed to be

embedded in OEM terminals, PCs and data gathering

equipment, and as such the equipment it is embedded in

will not normally carry RIM’s name.

OSI The Open Systems Interconnection model allows different

systems, following the applicable standards, to

communicate openly with each another.

Polarity Direction of current flow. Connecting some cables with the

wrong polarity (i.e. backward) may damage the device.

Radio Modem A device which provides modulation and demodulation for

a radio frequency communications system.

Radiation In this document, “radiation” refers to the emission of

electromagnetic energy in the radio frequency (RF) band.

Do not confuse this with radioactive particle emissions

caused by nuclear reactions.

RAP Radio Access Protocol. An alternative to the MASC

protocol, found on the RIM 902M. Provides simpler

implementation and faster, reliable operation.

Return Loss A measure of antenna matching.

RF Radio Frequency.

RS-232 The standard asynchronous serial communications

interface used by most existing personal computers and

mini-computers. Usually refers to both the

communications protocol and the electrical interface.

SMA An RF connector type.

TTL Transistor-Transistor Logic. Used in digital circuits. Low

(0) is represented by ~0 V and High (1) is ~5 V.

Type Approvals These approvals are required by most governments before

radio transmitters and equipment containing radio

transmitters can be used. In the USA, a device must be

tested and certified by an independent lab which is

recognized by the FCC.

UART Universal Asynchronous Receiver/Transmitter. Used as an

interface between a microprocessor and a serial port.

VSWR Voltage Standing Wave Ratio. A measure of antenna

matching. See Chapter 5, Antenna Integration.

Index

Antenna

efficiency • 48

gain • 46

gain, maximizing • 48

physical location • 49

return loss • 47, 54

shielding • 49

SMA connector • 54

VSWR • 47, 54

Cables

serial • 27, 53

Embedded system • 53

Industry Canada Certification • ii

Interface

about • 35

connecting to • 27

connecting to an RS232 device • 43

pin descriptions • 37

UART • 54

Interface and Test Board

LED indicators • 11

MAN • 53

MASC • 53

MOA • 4

Mobitex • 53

overview • 4

packet switching • 5

Mounting

permanent • 26

requirements • 24

MPAKs • 5

Noise

FCC compliance statement • i, ii

noise immunity • 2

shielding • 49

OEM • 54

Power supply

about • 31

alkaline batteries • 33

automotive supplies • 34

load specifications • 31

plug-in supply • 34

rechargeable batteries • 32

56 Index: Shielding

Integrator’s Guide – RIM 902M OEM Radio Modem

Reliability

noise immunity • 2

RIM 900

battery life • 3

controlling • 43

features • 1

output power • 2

physical size • 3, 22

RS232 • 54

Schematics

8250 serial interface • 44

Shutdown • 42

Startup

turning the radio on • 42

TURNON • 38

Temperature range • 22

Intermec Technologies WANRIM902-6100 WIRELESS DATA TERMINAL User Manual RIM 902M Integrator s Guide

Intermec Technologies Corporation WIRELESS DATA TERMINAL RIM 902M Integrator s Guide

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