Microhard Systems 00P3 User Manual

Download

Operating Manual

And Professional Installation Guide

CompactRF

OEM Spread Spectrum Transceiver

Revision 1.00, Sept 15, 2000

Microhard Systems Inc.

#110, 1144 - 29th Ave. N.E. Calgary, Alberta T2E 7P1 Phone: (403) 248-0028 Fax: (403) 248-2762 www.microhardcorp.com

CompactRF

900 MHz OEM Spread Spectrum Transceiver

This manual contains information of proprietary interest to Microhard Systems Inc. It has been supplied in confidence to purchasers and users of the CompactRF, and by accepting this material the recipient agrees that the contents will not be copied or reproduced, in whole or in part, without prior written consent of Microhard Systems Inc.

Microhard Systems Inc. has made every effort to assure that this document is accurate and complete. However, the company reserves the right to make changes or enhancements to the manual and/or the product described herein at any time and without notice. Furthermore, Microhard Systems Inc. assumes no liability resulting from any omissions in this document, or out of the application or use of the device described herein.

Microhard Systems’ products are appropriate for home, office, or industrial use, but are not authorized for utilization in applications where failure could result in damage to property or human injury or loss of life.

The electronic equipment described in this manual generates, uses, and radiates radio frequency energy. Operation of this equipment in a residential area may cause radio interference, in which case the user, at his own expense, will be required to take whatever measures necessary to correct the interference.

Microhard Systems Inc.

Leaders in Wireless Telecom

#110, 1144 - 29th Ave. N.E. Calgary, Alberta T2E 7P1 Phone: (403) 248-0028 Fax: (403) 248-2762 www.microhardcorp.com

FCC Declaration of Conformity

This device complies with Part 15 of the 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 caused undesired operation.

Microhard Systems Inc.’s products are warranted against all failures which occur as a result of defective material or workmanship within 12 months of purchase by the user. This warranty does not extend to products that, in the opinion of Microhard Systems Inc., have been subject to misuse, accidents, lightning strikes, improper installation or application, nor shall it extend to units which have, in Microhard Systems Inc.’s opinion, been opened, tampered with or repaired by an unauthorized facility.

© 2000 by Microhard Systems Inc., All Rights Reserved. HyperTerminal is copyrighted by Hilgraeve Inc, and developed for Microsoft. Microsoft and Windows are registered trademarks of Microsoft Corporation. pcANYWHERE and Symantec are registered trademarks of Symantec Corp. All other products mentioned in this document are trademarks or registered trademarks of their respective holders. Manual Revision 1.00, Sept 15, 2000.

ii CompactRFTM Operating Manual

Contents

1. Introduction

1.0 Product Overview .............................................................................................................................................................................. 1

1.1 Features.............................................................................................................................................................................................. 1

1.2 About this Manual............................................................................................................................................................................. 2

1.3 Unpacking and Inspection ................................................................................................................................................................. 3

2. Electrical/Physical

2.0 Functional Block Diagram................................................................................................................................................................. 5

2.1 Pinout................................................................................................................................................................................................. 6

2.2 DC Characteristics............................................................................................................................................................................. 8

2.3 AC Characteristics.............................................................................................................................................................................. 9

3. Mode of Operation

3.1 Data Mode ....................................................................................................................................................................................... 11

3.2 Command Mode .............................................................................................................................................................................. 12

3.2.1 Menu Interface......................................................................................................................................................................... 13

3.2.2 AT Command Interface........................................................................................................................................................... 13

3.3 Switching Between Command and Data Modes.............................................................................................................................. 14

3.3.1 Switching Between AT Command Interface and Data Mode................................................................................................... 14

3.3.2 Switching Menu Interface and Data Mode.............................................................................................................................. 15

3.4 Sleep Mode...................................................................................................................................................................................... 15

4. Configuration

4.1 Quick Start Approach ...................................................................................................................................................................... 17

4.2 AT Commands................................................................................................................................................................................. 18

4.3 AT Registers .................................................................................................................................................................................... 21

4.4 Configuration Settings..................................................................................................................................................................... 22

S Register 101 - Operating Mode..................................................................................................................................................... 23

S Register 102 - Serial Baud Rate.................................................................................................................................................... 25

S Register 104 - Network Address................................................................................................................................................... 26

S Register 105 - Unit Address.......................................................................................................................................................... 26

S Registers 106 and 206 - Primary and Secondary Hopping Patterns.............................................................................................. 26

S Register 107 - Encryption Key...................................................................................................................................................... 28

S Register 108 - Output Power Level............................................................................................................................................... 28

S Register 109 - Hopping Interval.................................................................................................................................................... 29

S Register 110 - Data Format............................................................................................................................................................ 29

S Registers 111 and 112 - Packet Minimum and Maximum Size..................................................................................................... 30

S Register 116 - Packet Character Timeout ...................................................................................................................................... 30

S Registers 113 and 213 - Packet Retransmission/Packet Retry Limit ............................................................................................. 31

S Register 115 - Packet Repeat Interval........................................................................................................................................... 31

S Register 122 - Link Handshaking.................................................................................................................................................. 32

S Register 117 - Modbus Mode ........................................................................................................................................................ 32

S Register 120 and 121- RTS/DCD Framing/Timeout ..................................................................................................................... 33

5. Installation

A. Modem Command Summary...................................................................................................................................................................... 41

B. Serial Interface............................................................................................................................................................................................ 43

C. Factory Default Settings.............................................................................................................................................................................. 45

D Performance Tables...................................................................................................................................................................................... 47

..... ..............................................................................................................................................................................

F. Technical Specifications............................................................................................................................................................................. 51

G. Development Board Schematics ................................................................................................................................................................. 53

H. Mechanical Drawing................................................................................................................................................................................... 59

I. Glossary...................................................................................................................................................................................................... 61

S Register 123 - RSSI Reading......................................................................................................................................................... 33

5.1 Estimating the Gain Margin............................................................................................................................................................. 35

5.2 Antennas and Cabling...................................................................................................................................................................... 37

5.2.1 Internal Cabling ....................................................................................................................................................................... 37

5.2.2 Installing External Cables, Antennas and Lightning Arrestors................................................................................................ 38

iii CompactRFTM Operating Manual

iv CompactRFTM Operating Manual

1. Introduction

1.0 Product Overview

The CompactRFTM is a high-performance embedded wireless data transceiver. Operating in the 902-928 MHz ISM band, this frequencyhopping spread-spectrum module is capable of providing reliable wireless data transfer between almost any type of equipment which uses an asynchronous serial interface. The small-size and low operating current of this module make it ideal for mobile and battery powered applications. Typical uses for this module include:

n Automated Meter Reading (AMR); n Vending Machines; n Point of Sale Devices;

n Fleet Management; n Telemetry; n Remote Camera/Robot Control; n Security Systems; and, n Display Signs.

While a pair of CompactRFTM modules can link two terminal devices (“pointto-point” operation), multiple modules can be used together to create a network of various topologies, including “point-to-multipoint” and “repeater” operation. Multiple independent networks can operate concurrently, so it is possible for unrelated communications to take place in the same or a nearby area without sacrificing privacy or reliability.

1.1 Features

Key features of the CompactRFTM include:

n transmission within a public, license-exempt band of the radio

spectrum1 – this means that it can be used without access fees (such as those incurred by cellular airtime);

n a serial I/O data port with handshaking and hardware flow

control, allowing the CompactRFTM to interface directly to any equipment with an asynchronous serial interface.

902-928 MHz, which is license-free within North America; may need to be factory-configured differently for some countries.

CompactRFTM Operating Manual: Chapter 1 Introduction. 1

n 30 sets of user-selectable pseudo-random hopping patterns,

intelligently designed to offer the possibility of separately operating multiple networks while providing security, reliability and high tolerance to interference;

n encryption key with 65536 user-selectable values to maximize

security and privacy of communications;

n built-in CRC-16 error detection and auto re-transmit to provide

100% accuracy and reliability of data;

n ease of installation and use – the CompactRFTM gives the user

the choice of a menu interface, or a subset of standard AT style commands, very similar to those used by traditional telephone line modems.

While the typical application for the CompactRFTM is to provide a short- to mid-range wireless communications link between DTEs, it can be adapted to almost any situation where an asynchronous serial interface is used and data intercommunication is required.

1.2 About this Manual

This manual has been provided as a guide and reference for installing and using CompactRFTM wireless transceivers. The manual contains instructions, suggestions, and information which will help you set up and achieve optimal performance from your equipment using the CompactRFTM.

It is assumed that users of the CompactRFTM have either system integration or system design experience. Chapter 2 details the physical/electrical characteristics of the module. Chapter 3 gives an overview of the modes of operation. Chapter 4 describes the AT command register/menu setup and configuration. Chapter 5 is an installation/deployment guide. The Appendices, including the Glossary of Terms, are provided as informational references which you may find useful throughout the use of this manual as well as during the operation of the product.

Throughout the manual, you will encounter not only illustrations that further elaborate on the accompanying text, but also several symbols which you should be attentive to:

Caution or Warning: Usually advises against some action which could result in undesired or detrimental consequences.

Point to Remember: Highlights a key feature, point, or step which is worth noting, Keeping these in mind will make using the CompactRF more useful or easier to use.

Tip: An idea or suggestion is provided to improve efficiency or to make something more useful.

With that in mind, enjoy extending the boundaries of your communications with the CompactRFTM.

2 CompactRFTM Operating Manual: Chapter 1 Introduction

1.3 Unpacking and Inspection

The following items should be found in the shipping carton. Inspect the contents for any shipping damage. Report damages or shortages to the distributor from which the unit was purchased. Keep all packing materials in the event that transportation is required in the future.

Package contents for the CompactRF development kit (normal distribution):

CompactRFTM Wireless Module 2 Operating Manual (this document) 1 3 12V Wall Adapter 2 4 DB9 Straight-through Serial Cable 2 5 Rubber Duck Antenna 2 6

CompactRFTM Development Board

CompactRFTM Operating Manual: Chapter 1 Introduction. 3

4 CompactRFTM Operating Manual: Chapter 1 Introduction

2. Electrical/Physical

2.0 Functional Block Diagram

DVcc

AVcc

GND

\Config

\Reset \Sleep

TxD RTS DTR

Comparator

A/D

IF Demod

SRAM

Mixer

Frequency

Synthesizer

8 bit data bus

UART (DCE)

ARSSI

LNAMixer

Antenna

Switch

GAIN

RSSI1-3 SYNC RXMODE TXMODE

EEPROM

RxD CTS

DSR

DCD

CompactRFTM Operating Manual: Chapter 2 Electrical/Physical 5

2.1 Pinout

Figure 1 provides a top-view pinout drawing of the CompactRF module. The corner pins (1,18,19,36) are labeled directly on the module.

NC NC NC NC

\Config

SYNC RSSI1 RSSI2 RSSI3

Rx Mode

Tx Mode

PGM GND GND GND GND GND AVcc

1 2 3 4 5 6 7 8

CompactRF

9 10

900MHz

11 12 13 14 15 16 17 18

T M

36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19

AVcc GND ARSSI NC NC \Reset DVcc GND TxD RxD GND DSR CTS DCD RTS DTR SCK \Sleep

Figure 1 - Pinout (Top View)

Pin Name No. Description I/O

ARSSI 34 Provides an analog level of the received signal

strength. This is an uncalibrated signal, and will provide only rough measurements of signal strength.

AVcc 18,36 Positive Supply for Radio Circuitry. See Section

2.1 for DC Characteristics

\Config 5 Momentarily assert low to enter configuration

mode. See Section 2.2

CTS 24 RS-232 Clear to Send. Active low (TTL level)

output. See Appendix B for a complete description of all RS-232 signals.

DCD 23 RS-232 Data Carrier Detect. Active low (TTL

level) output.

DSR 25 RS-232 Data Set Ready. Active low (TTL level)

output.

6 CompactRFTM Operating Manual: Chapter 2 Electrical/Physical

Pin Name No.

DTR 21

Description

RS-232 Data Terminal Ready. Active low (TTL level) input.

I/O

DVcc 30

GND 13-17

26,29, 35

PGM 12

\Reset 31

SYNC 6

RSSI1 7

RSSI2 8

RSSI3 9

RTS 22

RxD 27 RXMODE 10

SCK 20

TxD 28 TXMODE 11

\Sleep 19

Positive Supply for Logic circuitry and I/O pins. See Section 2.2 for DC Characteristics

Ground reference for logic, radio and I/O pins.

Programming Status indicator. This output is for factory use only, and should normally be left disconnected.

Active low reset input to the module. See Section 2.3 for timing information.

Active high output indicates the modem is synchronized with at least one other modem

Receive Signal Strength Indicator 1. This output is the first of the three RSSI indicators to become active high as the signal strength increases. See Table 2 for details

Receive Signal Strength Indicator 2. This output is the second RSSI indicator to become active high as the signal strength increases. See Table 2 for details.

Receive Signal Strength Indicator 3. This output is the last RSSI indicator to become active high as the signal strength increases. See Table 3 for details.

RS-232 Request to Send. Active low (TTL level) input.

RS-232 Receive Data. TTL level output. Active high output indicates module is

receiving data over the RF channel. ISP Programming Clock. Used in conjunction

with RxD and TxD when upgrading the FLASH-based firmware.

RS-232 Transmit Data. TTL level input. Active high output indicates module is

transmitting data over the RF channel. Assert low to put the unit to sleep. See

Section 2.3 for timing information.

O O

I O

NC 1-4,

32,33

CompactRFTM Operating Manual: Chapter 2 Electrical/Physical 7

No Connect

For detailed mechanical drawings, refer to Appendix H

2.2 DC Characteristics

Sym Characteristic Min Typ Max Units

AV DV V V

AI AI

AI DI DI V V V V I

POT

RST

SRCE

Radio Supply Voltage 4.9 5.0 5.5 V

Logic Supply Voltage 4.75 5.0 5.5 V

Power On Reset Threshold Voltage 1.8 2 2.2 V Reset Pin Threshold Voltage DVCC/

Radio Supply Current in Receive Mode 54 60 66 mA

CCR

Radio Supply Current at 1mW Transmit 68 75 82 mA

CCT

Radio Supply Current at 10mW Transmit 96 107 118 mA

CCT

Radio Supply Current at 100mW Transmit 185 206 227 mA

CCT

Radio Supply Current at 1W Transmit 517 575 633 mA

CCT

Radio Sleep Current 500 uA

Logic Supply Current 22 25 28 mA

Logic Sleep Current 1.0 mA

Input Low Voltage (Pins 5,19,21,22,28) -0.5 .3DV Input High Voltage (Pins 5,19,21,22,28) 0.6V

Output Low Voltage (Pins 6-11,23-25,27) 0.6 V Output High Voltage(Pins 6-11,23-25,27) 4.2 V Sourcing Current (Pins 6-11,23-25,27) Per

VCC+.5 V

10 mA

8 CompactRFTM Operating Manual: Chapter 2 Electrical/Physical

2.3 AC Characteristics

Sym Characteristic Min Typ Max Units

T T T T T T

Reset Delay Time-Out Period 12.8 16.0 19.2 ms

TOUT

\Config. pulse duration See Note ms

CFG

\Sleep low to internal sleep delay 0 See Note ms

S2SD

Snooze duration 10 ms

Sniff duration 100 us

SNIFF

\Sleep high to internal wakeup 0 T

WDLY

Note: The minimum duration for T and is stored in register S109. The maximum delay for T

is one hop interval. The hop interval is set by the user,

CFG

is also one hop interval.

S2SD

Figure 2 provides timing information for both power-up reset and the \Reset line operation. A fixed internal reset delay timer of roughly 16ms is triggered as the V

Internal Reset

or V

POT

\Reset

threshold is reached.

RST

VDV

POT

RST

TOUT

Figure 2. Reset Timing

Figure 3 illustrates the sleep operation for the CompactRF. When the \Sleep line is asserted, the modem will internally go to sleep within one hop interval. While sleeping, the modem will “sniff” every 10 ms to check if the \Sleep line has again gone high. If the \Sleep line is low, the modem goes back to sleep. If it is high, the modem wakes up and resumes normal operation.

\Sleep

S2SD

\Internal Sleep

SNIFF

WDLY

Figure 3. Sleep/Wakeup Timing

CompactRFTM Operating Manual: Chapter 2 Electrical/Physical 9

10 CompactRFTM Operating Manual: Chapter 2 Electrical/Physical

3. Modes of Operation

The CompactRFTM modem can be easily configured to meet a wide range of needs and applications. The module is designed such that all communication is through one serial port (Pins 21 to 28 on the module). This port has two functions:

1. It provides the asynchronous interface with the host equipment for data that is sent/received on the RF channel. When operating in this fashion, the module is said to be in data mode.

2. It is also used for configuring and programming the module. When operating in this fashion, the module is said to be in command mode.

In addition to data mode and command mode, there is a third mode of operation called sleep mode. The module will always be in one of these three modes.

3.1 Data Mode

Data mode is the normal operating mode of the CompactRF. When in data mode, the CompactRF is communicating with other CompactRF modules, and facilitating wireless asynchronous serial communication amongst two or more terminal devices. There are three basic elements to any CompactRF communications network:

• One module configured as the Master

• Zero or more modules configured as Repeaters

• One or more modules configured as Slaves

The function of the Master is to provide synchronization for the entire network, and to control the flow of data. There is always one Master per network. The Master is the ultimate destination for all data collected at the various Repeater’s and Slave’s serial ports. With the network set up for Point-to-Multipoint communication, all data received at the Master’s serial port is transmitted to every Repeater and Slave in the network. The CompactRF is a frequency hopping transceiver, meaning that it “hops” to a new frequency after a predetermined time interval. This time interval is a fixed time set by the user, and can range from 14ms to 180ms. The CompactRF hops according to a pseudorandom pattern of 50 different channels.

CompactRFTM Operating Manual: Chapter 3 Modes of Operation 11

Network 1

MSRM

Network 2

Network 3

Network 4

When configured as a Slave, the CompactRF searches for synchronization with a Master. Network topologies consisting of a single Master and

virtually any combination of Slaves and Repeaters may be deployed. The functionality of any particular CompactRFTM can be configured as follows:

n Master Point-to-Point: The modem is configured to

communicate with a single Slave, either directly, or through one or more Repeaters.

n Master Point-to-Multipoint: The modem is configured to

communicate with one or more Slaves and/or Repeaters.

n Slave: The modem is configured to communicate with one

Master either directly or through one or more Repeaters..

n Repeater: The modem is configured to pass information from

either a Master or another Repeater onto subsequent Repeaters and/or Slaves and vice versa. The Repeater also acts as a Slave

in the sense that, like a Slave, it passes information to/from its serial port.

Examples of different network topologies are shown in Figure 4. Network 1 shows Point-to-Point communication between a Master and Slave. Network 2 makes use of a Repeater to communicate with the Slave. Network 3 illustrates a simple Point-to-Multipoint network with no

Repeaters. Networks 4 and 5 gives examples of Point-to-Multipoint networks consisting of both Repeaters and Slaves. There is effectively no restriction to the number of Repeaters and Slaves that can be added to a network. As seen in Network 4, a Master can communicate directly with

both Slaves and Repeaters.

3.2 Command Mode

M R

Network 5

Figure 4 - Sample Network Topologies. Virtually any

Combination of Slaves and Repeaters May be Used.

between two different Command Mode interfaces: Menu Interface; or, AT Command Interface. The menu interface is ideal for applications which involve human configuration of the operating parameters of the modem. The AT Command interface is more suited for direct interface with another microcontroller or for higher level Windows-based software applications. The CompactRF development board is a useful tool for familiarizing yourself with the various operating parameters and user interface. Reference schematics for the development board can be found in Appendix G. To access the CompactRF’s command mode using the development board:

1. Insert the module into the socket with the antenna connector towards the edge of the board.

2. Attach the supplied antenna.

3. Connect a straight through serial cable between the DB9 connector and the serial port on your PC

4. Apply power to the development board

5. Run any terminal application program such as Hyperterminal

6. Set the serial port to 9600 baud, 8N1

7. Momentarily press the configure (CFG) button

The CompactRF firmware has been designed to allow the user to select

12 CompactRFTM Operating Manual: Chapter 3 Modes of Operation

Menu selections are immediately stored to the module’s non-volatile memory.

3.2.1 Menu Interface

At this point, you should see a menu similar to the following appear:

Microhard Systems Inc CompactRF Configuration

1) Operating Mode S101=1 MasterPP 2) Serial Baud Rate S102=4 9600

3) Network Address S104=255 4) Unit Address S105=65535

5) Hopping Pattern S106=0 6) Encryption Key S107=65535

7) Output Power Level S108=0 1 mW 8) Retry Limit S213=255

9) Hop Interval S109=20 x 0.74 ms = 14 ms

D) Autoanswer S0=1 E) Interface S6=0 AT style A) Handshaking &K3 Enabled N) DTR &D0 Ignored O) DSR &S0 ON in Data Mode M) DCD &C1 ON when sync'd S2=43 S3=13 S4=10 S5=8 Type AT for AT interface or hit Enter for menu

You now have the option of choosing between the menu interface, or the AT Command interface.

For menu operation, hit ENTER. You should see the following prompt:

Enter Command :

Now, the CompactRF will respond to your menu selection. For example, to change the unit’s Operating Mode, press the 1 key. The following sub-menu will appear:

Operating Mode * 1) MasterPP

2) SlavePP

ESC to exit Select Operating Mode :

The instant a selection is made, it is immediately stored into the module’s non-volatile memory.

3.2.2 AT Command Interface

The CompactRF may also be controlled through an AT Command line interface, using a command set which is very similar to a traditional Hayes telephone modem command set.

For AT Command operation, instead of hitting ENTER at the prompt, type AT <ENTER>. The characters ‘AT’ are known as the attention characters and must be typed at the beginning of each command line. The modem should respond with OK. Illustrating the same example as above to configure the Operating Mode using AT Commands, type the following:

ATS101=2 <ENTER> The modem should respond with ’OK.’ The above command will set the

operating mode to SlavePP (Slave Point to Point).

CompactRFTM Operating Manual: Chapter 3 Modes of Operation 13

When using AT Commands, use the &W command to store the most current settings to memory.

With AT Commands, the settings are not immediately stored to non-volatile memory, therefore if the modem is powered down at this point, the Operating Mode would revert to its previous value. To store any recently updated command registers, the following “write” command must be entered.

AT&W <ENTER>

3.3 Switching Between Command and Data Modes

The method for switching between data and command modes depends on which interface you are using (Menu or AT). There is a parameter called “Interface” (Menu item E) which defines whether the modem is currently operating in AT mode or Menu mode.

3.3.1 Switching Between AT Command Interface and Data

Mode

Your modem must be in Command Mode for it to execute a command. If you send characters when the modem is in Data Mode, the modem transmits the characters over the air.

Depending on its settings, the modem will either power up in Command Mode or Data Mode. Normally, when first received from the factory, the unit will power up in Command Mode. In this mode of operation, the module “autobauds,” meaning that it will adapt to the baud rate of the DTE equipment to which it is connected. Therefore, when in Command Mode, you may change the baud rate of your equipment, and the CompactRF will automatically adjust to this baud rate once an AT string is issued. The new baud rate is stored in register S102. Several baud rates ranging from 2400 to 19200 may be selected.

You can place the modem into Data Mode either by:

• Issuing the answer command (ATA <ENTER>); or,

• Issuing the online command (ATO <ENTER>).

14 CompactRFTM Operating Manual: Chapter 3 Modes of Operation

The modem will now attempt to communicate with other CompactRF modules. While in Data Mode, the modem will communicate through the serial port at the same baud rate as was last used in Command Mode2.

To return to Command Mode, you can either:

The escape sequence will not be accepted unless both the CompactRFTM and the terminal are set to the same baud rate

\SLEEP \CONFIG

DATA

MODE

ESC \SLEEP

COMMAND

MODE

ESC \SLEEP

\SLEEP \CONFIG

\SLEEP

SLEEP MODE

\SLEEP

Figure 5a - Menu Interface State Diagram

\SLEEP

DATA

MODE

• Send the escape sequence. (The escape sequence consists of 1 second of inactivity, followed by the characters ‘+++’ followed by another second of inactivity.); or,

• Toggle the DTR line (depending on the &D parameter see pg 11).

The escape sequence must be issued at the baud rate that the modem has been set to. If the modem is set to 19200 baud, and the escape sequence is issued at 9600 baud, for example, the modem will not recognize it, and will not go into Command Mode.

3.3.2 Switching Between Menu Interface and Data Mode

When configured for Menu Interface operation, the CompactRF may be placed into Command Mode from Data Mode by momentarily asserting the \Config line. This line runs out to a pushbutton on the development board. Press this button and wait for the menu interface to appear on the screen. The terminal must be set to 9600 baud when using the menu interface.

To switch back to Data Mode, from the main menu, hit the ESC key. You should see the response “Running...” The modem will run in Data Mode at the baud rate setting defined by Menu Item 2) Serial Baud Rate.

3.4 Sleep Mode

As mentioned at the beginning of this chapter, the CompactRF has a sleep mode of operation. Figure 5 is a state diagram representation of the three modes of operation. Figure 5a is the menu interface state diagram, and Figure 5b is the AT interface state diagram. The CompactRF enters into Sleep Mode when \SLEEP is asserted (active low). The module remains in Sleep Mode until this line is deasserted. See Chapter 2 for timing information. When in Sleep Mode, the module drives all outputs pins (Pins 6-11,23-25,27) at their inactive levels.

(ATA or ATO Command)

COMMAND

MODE

DTR or Escape Sequence

\SLEEP

SLEEP MODE

It is possible to enter into Data Mode at a different baud rate from what is currently being used in Command Mode by issuing the command ATS102=x, where x is one of the valid baud rates. Care must be taken when setting the baud rate in this manner. If you issue another AT string after attempting to set the baud rate using ATS102 <ENTER>, the modem will again autobaud and automatically revert to the baud rate of the host

\SLEEP

Figure 5b - AT Interface State Diagram

equipment. For example, if your equipment is running at 9600 baud and you wish to set up the modem to run at 19200 baud, the following command line entry would achieve this:

ATS102=2&WA <ENTER> The first part (S102=2) sets the baud rate to 19200. The next characters (&W) write this baud rate to memory. The last character (A) puts the modem into Data Mode. Once in Data Mode, the modem is unable to autobaud, and is fixed at 19200 baud. By combining several commands into one command line entry, and then immediately putting the modem online, the modem is not given a chance to autobaud back to 9600.

CompactRFTM Operating Manual: Chapter 3 Modes of Operation 15

16 CompactRFTM Operating Manual: Chapter 3 Modes of Operation

4. Configuration

This chapter provides a detailed description of the various operating parameters of the CompactRF. Section 4.1 provides a quick-start approach which outlines the minimum requirements for establishing communication between two CompactRF modules. The settings will not necessarily provide optimal performance for your application, but will verify that the modules are functioning correctly.

Section 4.2 describes the AT Command interface. Section 4.3 describes the set of registers which are unique to AT operation, and not used in menu mode.

Section 4.4 covers all parameters that are common to both the AT Command interface and the Menu interface.

4.1 Quick Start Approach

Whether you are using the AT Command interface or the Menu interface, there are several parameters that must be set in order to establish communication between a pair of CompactRF modules.

The CompactRFTM is equipped with four standard factory default settings. Instead of manually configuring each individual operating parameter, a global command may be used to quickly configure the modem for a particular type of operation. For example, to quickly implement Network 1, Factory default 1 would be applied to the Master, and Factory default 2 would be applied to the Slave. To quickly set up Network 2, apply Factory 1 to the Master, Factory 3 to the Repeater, and Factory 4 to the Slave. These defaults will get

you started and only ensure that a link can be established, but do not

necessarily provide the best performance. Optimization of the

communications link is discussed in later sections.

Network 1

MSRM

Network 2

Figure 6. Basic Networks

CompactRFTM Operating Manual: Chapter 4 Configuration 17

To implement the basic network illustrated in Figure 6, Network 1,

Using AT Commands Using Menu Interface

Connect a straight-through serial cable between the development board and the

terminal

Connect an antenna to the module

Power up the development board

See Section 3.3 If you have problems getting into Command Mode.

Configure the unit to Factory Setting 1 by typing AT&F1 <return>. This puts the unit into Master Point-to-point mode.

Store these settings to memory by typing AT&W <return>.

Put the modem into Data Mode by typing ATA (or ATO) <return>

Perform above steps for the second unit, using Factory Setting 2 instead of Factory Setting 1. This will configure the second unit as a Slave.

Configure the unit to Factory Setting 1 by selecting menu option F). You should see the following:

Factory Settings

1) Factory Master

2) Factory Slave

3) Factory Slave Through Repeater

4) Factory Repeater * 5) Manual

Select menu item 1) Put the modem into Data Mode by

pressing the ESC key.

The units should now be communicating. Remember, the parameters defined by Factory Settings 1 and 2 will likely not be the most ideal for your application, but will quickly allow you to test the units. A complete summary of the settings defined by all four factory settings can be found in Appendix C. Factory Default Settings.

Settings are not immediately stored in non-volatile memory when using AT Commands, therefore, the command &W is issued to store the current configuration into non-volatile memory. Settings are retained even after powering down. All user selectable parameters for the CompactRFTM are described in detail in Section 4.4: Configuration Settings.

Checking the Link

To check if the units are communicating, observe the LED indicators on the development board. If the link is good, up to three RSSI LED’s on the Master and Slave modems should be active; and if the link is absent (due to a fault at one end or another, such as misconfiguration), the LED’s will be in either “scanning mode” or inactive.

Characters typed at the Master terminal should appear at the Slave’s terminal, and vice versa. Also, verify that the RX LED blinks as packets of data are received at the Master modem. As data is sent from Slave to Master, the RX indicator should blink on as correct packets of data are received. It is recommended that if the CompactRFTM will be deployed in the field where large distances separate the units, the modems should be configured and tested in close proximity (e.g., in the same room) first to ensure a good link can be established and settings are correct. This will facilitate troubleshooting, should problems arise.

4.2 AT Commands

Several AT Commands are supported by the CompactRFTM. The commands discussed in this section do not have a menu interface equivalent. More commands and S-Register settings are discussed in Sections 4.3 and 4.4.

To make the command line more readable, you can insert as many spaces as desired. The command line holds up to 16 characters, not including the AT prefix. If you want to send more than one command line, wait for a response before entering the AT prefix at the start of the next command line.

To re-execute the previous command, enter A/. The modem will execute the previous command line.

When in Command Mode, the modem “autobauds”, meaning that it will automatically adjust to the baud rate of the terminal. You may change the terminal baud rate while in Command Mode without losing communication with the modem.

For the AT command protocol, an escape sequence consists of three consecutive escape codes preceded and followed by at least 1 second of inactivity. Typically, the ‘+’ character is used as the escape code.

+++ preceded and followed by 1 second of inactivity

18 CompactRFTM Operating Manual: Chapter4 Configuration

Note that the terminal must be configured to the same baud rate as the modem in order for the modem to recognize the escape sequence. The modem is unable to “autobaud” while in Data Mode.

The following is a description of all available commands. ‘*’ denotes standard factory settings. All of the following commands must be preceded by “AT”.

A Answer

The A command causes the modem to attempt to connect with another remote modem (Type ATA <return>).

E Command Echo

Your modem is preset to return (or echo) commands to the host microprocessor when in Command Mode.

E0 No Command Echo

*E1 Command Echo

I Identification

The I command returns various modem information settings.

I0 Product Code (CompactRF)

I2 Issue ROM Check (OK or ERROR)

I3 Product Identification (Firmware Version)

I4 Firmware Date

I5 Firmware Copyright

I6 Firmware Time

O On-line Mode

The O command attempts to put the modem online and communicate with a remote modem.

Q Quiet Mode

Your modem is preset to send responses when it executes commands, and there after to keep the host informed of its status.

*Q0 Enable modem responses

Q1 Disable modem responses

V Result Codes display

Your modem can either display result codes as words or numbers.

V0 Display Result Codes as numbers

*V1 Display Result Codes as words

W Connection Result

This parameter determines the modem response at the transition from Data Mode to Command Mode

*W0 Reports computer (DTE) baud rate as CONNECT xxxx

W1 Reports wireless rate between modems as CARRIER

xxxx.

W2 Reports modem (DCE) baud rate as CONNECT xxxx

Z Reset and load stored configuration

The Z command resets the modem and loads the stored configuration.

CompactRFTM Operating Manual: Chapter 4 Configuration 19

&V View Configuration

The &V command displays all S registers and their current values.

&E Framing Error Check NOT YET IMPLEMENTED

This command enables or disables Framing Error Check. When enabled, the modem looks for the stop bit. If the stop bit is absent, the byte is thrown out. When enabled, the modem also does a parity check. Note that the data format (number of data bits, parity type, and number of stop bits) is defined by S register 110.

*&E0 Disable Framing Error Check

&E1 Enable Framing Error Check

&W Write Configuration to Memory

The &W command stores the active configuration into the modem’s nonvolatile memory.

Sxxx? Read S register value

This command causes the modem to display the current setting of S register xxx.

Sxxx=yyy Set S register value (see section 3.3 S-Registers)

This command sets the specified S register to a value specified by yyy.

AT Command Result Codes

The CompactRFTM module can either display the results of a command as either text strings or numerical data. The following chart shows resulting text string and corresponding numeric result.

0 OK

3 NO CARRIER

4 ERROR

7 CONNECT 2400

8 CONNECT 3600

9 CONNECT 4800

10 CONNECT 7200

12 CONNECT 9600

13 CONNECT 14400

14 CONNECT 19200

15 CONNECT 28800

17 CONNECT 38400

18 CONNECT 57600

33 CONNECT 115200

62 CARRIER 45000

64 CARRIER 20000

20 CompactRFTM Operating Manual: Chapter4 Configuration

S Registers 2 through 5 cannot be stored to nonvolatile memory.

4.3 AT Registers

The parameters described in this section apply to AT Command operation only.

S Register 0 - Auto Answer

If this register is set to zero, the modem will power up in command mode. If this register is non-zero, the modem will power up in data mode.

S Register 2 - Escape Code

This register contains the ASCII value of the escape character. The default value (decimal 43) is equivalent to the ASCII character ‘+’.

Values greater than 127 disable the escape feature and prevent you from returning to the Command Mode. This register cannot be stored to nonvolatile memory. If the modem is reset, or powered down, the default value is restored.

Default is ‘+’ (decimal 43).

S Register 3 - CR Control Code

This register contains the ASCII value of the carriage return character. This is the character that is used to end the command line and is also the

character that appears after the modem sends a response. This register cannot be stored to non-volatile memory. If the modem is reset, or powered down, the default value is restored.

Default is ‘CR’ (decimal 13).

S Register 4 - Linefeed Control Code

Register S4 sets the ASCII value of the linefeed character. The modem sends the linefeed character after sending a carriage return

character when sending text responses. This register cannot be stored to non-volatile memory. If the modem is reset, or powered down, the default value is restored.

Default is ‘LF’ (decimal 10).

S Register 5 - Backspace Control Code

Register S5 sets the ASCII value of the backspace character. This character is both the character created by entering BACKSPACE and

the character echoed to move the cursor to the left. This register cannot be stored to non-volatile memory. If the modem is reset, or powered down, the default value is restored.

Default is ‘BS’ (decimal 8).

CompactRFTM Operating Manual: Chapter 4 Configuration 21

4.4 Configuration Settings

The parameters described in this section affect the operating characteristics of the CompactRF module. All the settings described in this section can be configured using either the AT Command interface or the menu interface.

AT Menu

DCD (Data Carrier Detect) &C M

The &C command controls the modem’s DCD output signal to the host microprocessor. This command determines when the DCD is active.

&C0 DCD is always ON

*&C1 DCD on when modems are synchronized. DCD is always

on when unit is configured as Master.

&C2 DCD used for output data framing and Modbus mode.

See page 24 for details.

AT Menu

DTR (Data Terminal Ready) &D N

The &D command controls what action the modem performs when the DTR input line is toggled. The DTR input is controlled by the host microprocessor.

*&D0 DTR line is ignored

&D1 Not Supported

&D2 DTR disconnects and switches to Command Mode

&D3 DTR disconnects and resets modem. Modem will remain

in this state until DTR again goes active.

&F1

Master Slave

&F1

Master

&F2

&F3

Repeater

&F4

Slave

AT Menu

Load Factory Default Configuration &F F

The &F command resets the modem and loads the default factory configuration.

&F1 Master Point-to-Multipoint. Designed to communicate

with modems configured as &F2 or &F3.

&F2 Slave. Designed to communicate with another modem

configured as &F1.

&F3 Repeater. Designed to communicate with modems

configured as &F1 and &F4.

&F4 Slave working with factory default Repeater and factory

default Master. Communicates directly with Repeater configured as &F3.

22 CompactRFTM Operating Manual: Chapter4 Configuration

AT Menu

Handshaking &K A

This command controls the handshaking between the modem and host microprocessor.

&K0 Disable handshaking

&K2 RTS/CTS input data framing. See page 33 for details.

*&K3 Enable hardware handshaking (RTS/CTS)

AT Menu

DSR (Data Set Ready) &S O

This command controls the DSR line for the modem, and determines when it is active

&S0 DSR is always ON

*&S1 DSR is ON in Data Mode, OFF in Command Mode

AT Menu

Operating Mode S101 1

Only one Master can exist for each network.

The Operating Mode (register S101) partly defines the “personality” of the CompactRFTM module. Allowable settings for this register are 1 through 4 as follows:.

• S101=1 Master Point to Multipoint

• S101=2 Master Point to Point

• S101=3 Slave

• S101=4 Repeater

The default for this register depends on which factory default is selected as shown below:

• Default for Factory Setting &F1 is 1 (Master Point-to-Multipoint)

• Default for Factory Setting &F2 is 3 (Slave)

• Default for Factory Setting &F3 is 4 (Repeater)

• Default for Factory Setting &F4 is 3 (Slave)

1)Master - Point to Multipoint. In any given network, there is always only one Master. All other units should be configured as either Slaves or Repeaters. When defined as a Point-to-Multipoint Master, the modem broadcasts data to all Slaves and Repeaters in the network, and is also the ultimate destination for data transmitted by all Slaves and Repeaters. In addition, the Master defines the following network parameters to be utilized by all other modems in the network (See the appropriate sections for a complete description of these parameters):

n Maximum Packet Size (S112) n Minimum Packet Size (S111) n Link Handshaking (S122) n Wireless Link Rate (S103) n Hop Interval (S109)

CompactRFTM Operating Manual: Chapter 4 Configuration 23

Network 50

Hop Pattern 2

PHP=1

Master

Hop Pattern 1

PHP=1 SHP=2

Repeater

PHP=2

Slave

Figure 7 - Repeater Operation

Hop Pattern 3

Repeater

PHP=2

SHP=3

Master Repeater

PHP=1

HopPattern 1

PHP=1 SHP=2

Hop Pattern 2

Slave

PHP=2

Figure 8 - A Network Utilizing Three Hopping Patterns

If there is no DTE connected to the Repeater, turn off handshaking (&K0) and set the baud rate to 115K.

Slave PHP=3

2)Master - Point to Point. This mode of operation is identical to Master Point-to-Multipoint, with the exception that the Master only broadcasts to one particular Slave or Repeater. The modem with which communication occurs is defined by the Unit Address (S105). For example, if a Slave has been assigned Unit Address 100, and the Master wishes to communicate with that Slave, the Master must also be assigned a Unit Address of 100. If there are Repeaters in the network, they will pass the packet through to the Slave, and vice versa. Because Repeaters also have Slave functionality (i.e., a Repeater can be connected to a terminal), the Master can choose to communicate solely with a Repeater. This would be accomplished by assigning the same Unit Address to both the Master and the Repeater.

3)Slave. Up to 65534 Slaves may exist in a network, all of which communicate with the common Master (either directly or via Repeater(s)). Slaves cannot directly communicate with other Slaves, nor can they acknowledge packets of data sent by the Master. Clearly this would cause conflicts when there are multiple Slaves. The Master does, however, send acknowledgements to all messages it receives from Slaves. The Master initiates communications by sending a broadcast message to all Slaves. All Slaves are free to respond in a “Slotted ALOHA” fashion, meaning that each Slave can choose one of several windows in which to transmit. If there happens to be two Slaves attempting to talk at the same time, the Master may not receive the data, and the Slaves therefore would not get an acknowledgement. At this point, the Slaves would attempt to get the information through at random time intervals, thus attempting to avoid any more conflicts. Special parameters which control the Slave’s response characteristics can be modified with S Registers S115 and S213.

4) Repeater. A more precise title would be Repeater/Slave, because a Repeater also has much of the same functionality as a Slave. A terminal can be connected at the Repeater location and communicate with the Master terminal. There is no restriction to the number of Repeaters in a network, allowing for communication over virtually limitless distances. The presence of one Repeater in a network automatically degrades system throughput by half. Additional Repeaters, regardless of the quantity, do not diminish system throughput any further. To understand Repeater operation, consider the module as belonging to two hopping patterns at the same time: The Primary Hopping Pattern and the Secondary Hopping Pattern. In Figure 7, the Master belongs to Hopping Pattern 1, and communicates with the Repeater on this hopping pattern. The Slave belongs to Hopping Pattern 2, and communicates with the Repeater on this hopping pattern. The whole system belongs to Network 50 (i.e., all units must be assigned the same Network Address (S104), which in this case was selected to be 50. Note that Slaves and Master only communicate on their respective Primary Hopping Pattern. Repeaters communicate on the Primary Hopping Pattern when communicating with the Master (or with another Repeater between itself and the Master). Repeaters communicate on their Secondary Hopping Pattern when communicating with Slaves (or with another Repeater between itself and the Slaves). Figure 8 shows another example.

If the Repeater is not also being used as a Slave (there is no DTE connected to the serial port), it is recommended that the Repeater’s baud rate be set to 115K, and that handshaking be disabled (&K0). This will help ensure a smooth flow of data through the network.

24 CompactRFTM Operating Manual: Chapter4 Configuration

AT Menu

Serial Baud Rate S101 1

The Serial Baud Rate is the current speed that the modem is using to communicate with the DTE. When the AT command prefix is issued, the modem performs an ‘autobaud’ operation and determines what the current DTE baud rate is set to. The S register value returns the current setting of the DTE baud rate.

The possible values are:

* 1 115200

2 57600

3 38400

4 28800

5 19200

6 14400

7 9600

8 7200

9 4800

10 3600

11 2400

It is generally advisable to choose the highest rate that your terminal equipment will handle to maximize performance, unless a limitation on the available bandwidth is desired. If the DTE is a personal computer, the port can usually be used reliably at 115200.

The Master determines the Wireless Link Rate. This setting on all other modems is ignored..

CompactRFTM Operating Manual: Chapter 4 Configuration 25

Select a Network Address and assign it to all units which will be included in the network.

AT Menu

Network Address S104 3

The Network Address defines the communications network to which individual units can be a part of. By establishing a network under a common Network Address, the network can be isolated from any other concurrently operating network. As well, the Network Address provides a measure of privacy and security. Only those units which are members of the network will participate in the communications interchange. Valid values for the Network Address range from 0 to 65535, inclusive.

To enhance privacy and reliability of communications where multiple networks may operate concurrently in close proximity, it is suggested that an atypical value be chosen – perhaps something meaningful yet not easily selected by chance or coincidence.

Default is 1.

AT Menu

Use the same Unit Address on both units for point-topoint mode. In multipoint mode, set each Slave and Repeater to a different Unit Address.

Valid Unit Addresses are 1 to 65535.

Unit Address S105 4

In point-to-point operation, the Unit Address on both the Master and Slave (or Repeater) units must be the same. In a multipoint system, the Unit Address uniquely identifies each Slave and Repeater from one another. Each unit in a multipoint system must have a unique Unit Address ranging from 1 to 65535. Do not use 0 as a Unit Address, and do not use a Unit Address more than once within the same Network. This is required because the Master must be able to acknowledge each unit individually, based on the Unit Address.

AT Menu

Primary Hopping Pattern S106 5

Secondary Hopping Pattern S206 B

Since the CompactRFTM is a frequency-hopping modem, the carrier frequency changes periodically according to one of 30 pseudo-random patterns, defined by the Primary and Secondary Hopping Patterns. Valid entries for each are 0 through 29.

The concept of Primary and Secondary Hopping Patterns was introduced in the discussion of S Register 101 (Operating Mode).

Using the designations M[a,] Rx[a,b] and Sx[a] where:

- M indicates Master;

- R indicates Repeater;

- S indicates Slave;

- x is the Unit Address;

- a is the primary hopping pattern; and,

- b is the secondary hopping pattern;

26 CompactRFTM Operating Manual: Chapter4 Configuration

the following diagrams illustrate the methodology for deploying simple to complicated networks:

Master Slave

Master

Repeater

Master

Repeater1

Slaves and Masters do not use Secondary Hopping Patterns

Slave

Repeater2 Slave

M[1]

←→

S1[1]

R1[1,2]

←→

S2[2]

R2[2,3]

←→

S3[3]

R3[3,4]

←→

S4[4]

It is reasonable to consider a Repeater as being both a Slave and a Master, alternating between Primary and Secondary Hopping Patterns as the unit changes channel. Consider R1 in the illustration below. When communicating with the Master, R1 is acting like a Slave on Primary Hopping Pattern 1. When communicating with R2 and S4, R1 is acting like a Master on Secondary Hopping Pattern 2. If multiple Repeaters are used, they should have different Secondary Hopping Patterns:

M[1]

←→

R1[1,2]

R5[1,3]

R8[1,4]

←→

R2[2,5]

S4[2]

R6[3,6]

S9[4]

←→

S3[5]

S7[6]

Note that all units have a unique Unit Address.

Remember to assign a unique Unit Address (1 to

65535) to each unit in the system

Networks of any complexity can be created by linking multiple Repeaters and Slaves:

R1[1,2]

←→

←→ ←→

M[1] R4[1,3]

S11[1]

←→

S12[1]

←→

S2[2]

S3[2]

R5[3,6]

R8[3,7]

←→

S6[6]

S7[6]

R9[7,8]

←→

S10[8]

With a limitation of 62 hopping patterns, one might suspect that there is a limitation to the number of repeaters in a system. However, if the units are far enough away from one another, hopping patterns may be reused in different sections of the network, without causing interference.

CompactRFTM Operating Manual: Chapter 4 Configuration 27

All units within a network must use the same encryption key.

AT Menu

Encryption Key S107 6

The Encryption Key provides a measure of security and privacy of communications by rendering the transmitted data useless without the correct key on the receiver. Valid Encryption Keys range from 0 to 65535.

Keep in mind that all units within the network must use the same key for communications to succeed.

AT Menu

Output Power Level S108 7

The Output Power Level determines at what power the CompactRF

transmits. The CompactRFTM can operate with very low power levels, so it is recommended that the lowest power necessary is used; using excessive power contributes to unnecessary “RF pollution”.

The allowable settings are:

0 1 mW

1 10 mW

*2 100 mW

3 1000 mW

Ideally, you should test the communications performance between units starting from a low power level and working upward until the RSSI is sufficiently high and a reliable link is established. Although the conditions will vary widely between applications, typical uses for each setting are described below:

Power Use

1 mW

10 mW

100 mW

1000 mW

(1 W)

For in-building use, typically provides a link up to 300 feet on the same floor or up/down a level. Outdoors, distances of 1 km can be achieved if high-gain (directional) antennas are placed high above ground level and are in direct line-of-sight.

200-500 ft indoors, 2-5 km outdoors. 400-800 ft indoors, 4-8 km outdoors. Typically provides communications up to a distance of 1000 feet or

more in-building on the same floor or up/down a few levels, depending on building construction (wood, concrete, steel, etc.). In ideal line-of-sight conditions, up to 16 km or more can be achieved. Note that only an antenna with a gain of no more 6 dBi may be used. Any higher is a violation of FCC rules. See IMPORTANT warning below.

28 CompactRFTM Operating Manual: Chapter4 Configuration

FCC Regulations

IMPORTANT: FCC Regulations allow up to 36 dBi effective radiated power (ERP).

Therefore, the sum of the transmitted power (in dBm), the cabling loss and the antenna gain cannot exceed 36 dBi.

1 mW = 0 dBm 10 mW = 10 dBm 100 mW = 20 dBm 1000 mW = 30 dBm For example, when transmitting 1 Watt (30 dBm), with cabling losses of

2 dB, the antenna gain cannot exceed 36 - 30 + 2 = 8 dBi. If an antenna with a gain higher than 8 dBi were to be used, the power setting must be adjusted appropriately.

AT Menu

The hopping interval is controlled by the master. The slave and repeater units will use the hopping interval setting from the master.

Hopping Interval S109 9

This option determines the frequency at which the modems change channel. Note that the Master controls this parameter for the entire network. This setting is ignored in units configured as Slaves or Repeaters.

The allowable settings are 20 to 255. There is a multiplying factor of

0.74ms. For example, if you set the Hopping Interval to 20, the actual hopping interval will be 20 x 0.74ms = 14.8ms.

See Appendix D for optimal Hopping Interval settings in relation to packet size and link rate.

AT Menu

Data Format S110 C

This register determines the format of the data on the serial port. Allowable settings are:

*1 8 bits, No Parity, 1 Stop

2 8 bits, No Parity, 2 Stop

3 8 bits, Even Parity, 1 Stop

4 8 bits, Odd Parity, 1 Stop

5 7 bits, No Parity, 1 Stop

6 7 bits, No Parity, 2 Stop

7 7 bits, Even Parity, 1 Stop

8 7 bits, Odd Parity, 1 Stop

9 7 bits, Even Parity, 2 Stop

10 7 bits, Odd Parity, 2 Stop

11 9 bits, No Parity, 1 Stop

CompactRFTM Operating Manual: Chapter 4 Configuration 29

The Minimum and Maximum Packet Size is controlled by the Master. The Slave and Repeater units will use the Minimum and Maximum Packet Size setting from the Master.

AT Menu

Packet Minimum Size S111 G

Packet Maximum Size S112 H

Packet Character Timeout S116 I

These settings determine the conditions under which the modem will transmit accumulated data over the air.

S Register 111 - Minimum Size

Valid entries for this register are 1 to 255 bytes, which defines the minimum number of bytes to receive from the DTE before encapsulating them in a packet and transmitting over the air.

Note that the minimum packet size for all modems in the network is determined by the Master only. This setting is ignored in all Slave and Repeater modems. The default is 1 byte.

S Register 112 - Maximum Size

This setting has a range of 2 to 255, and defines the maximum number of bytes from the DTE which should be encapsulated in a packet. This value should be greater than the minimum packet size, but not smaller than is necessary for reliable communications. If the wireless link is consistently good and solid, a maximum size of 255 will yield the best throughput (depending on the higher level protocols of the connected equipment). However, if the link is poor (e.g., experiencing excessive interference) and data is frequently retransmitted, the maximum packet size should be reduced. This decreases the probability of errors within packets, and reduces the amount of traffic in the event that retransmissions are required.

Note that the maximum packet size for all modems in the network is determined by the Master only. This setting is ignored in all Slave and Repeater modems. The default is 255 bytes.

S Register 116 - Packet Character Timeout

This register has valid entries of 0 to 254 milliseconds. The Packet Character Timeout timer looks for gaps in the data being received from the DTE. The timer is only activated after the Minimum Packet Size has been accumulated in the modem. After which, if the timer detects a gap in the data exceeding the Packet Character Timeout value, the modem will transmit the data.

The CompactRFTM will accumulate data in its buffers from the DTE until one of the following requirements is met (whichever occurs first):

• The Maximum Packet Size (in bytes) has been accumulated;

• The Minimum Packet Size has been accumulated AND the Packet

Character Timeout interval has elapsed.

The default for the Packet Character Timeout is 9 ms. If set to 0 ms, the unit will buffer exactly the minimum packet size before transmitting.

30 CompactRFTM Operating Manual: Chapter4 Configuration

AT Menu

Packet Retransmissions S113 J

This register applies to both Master and Repeater operation. It does not apply to Slave operation. The Master will retransmit each data packet exactly the number of times defined by the Packet Retransmissions parameter. The Master retransmits once at the beginning of each hopping interval until the limit is reached. This parameter is not necessary in Slave units since all Slaves receive acknowledgement from the Master. As discussed previously, the Repeater effectively behaves as both a Master and a Slave. When the Repeater is tuned to its Secondary Hopping Pattern (acting as a Master), the Packet Retransmissions Parameter comes into play. The Repeater will re-send packets of data on to Slaves or other Repeaters exactly the number of times defined by the Packet Retransmissions parameter.

Recipients of the packet will discard any duplicates The valid settings for this parameter are 0 to 255 retransmissions. The default is 2.

AT Menu

Packet Retry Limit S213 K

Packet Retry Limit is analogous to Packet Retransmissions, but specifically applies to Slaves and Repeaters. This parameter is not used by the Master. Because the Slave has the advantage of receiving acknowledgements from the Master, it is not necessary to blindly retransmit each packet. If the Slave does not get an acknowledgement on the next hop, it will retransmit its packet. This will continue until the Packet Retry Limit is reached or an acknowledgement is received. If the limit is reached, the modem will give up and discard the data. Valid settings are 0 to 255 retries. The default value is 2.

The Repeater makes use of this parameter when it is tuned to its Primary Hopping Pattern and is acting like a Slave.

CompactRFTM Operating Manual: Chapter 4 Configuration 31

AT Menu

Packet Repeat Interval S115 L

A parameter that is specific to Slaves and Repeaters is the Packet Repeat Interval.

The allowable settings are 1 through 255. The default is 1.

This parameter defines a range of random numbers that the Slave will use as the next slot in which it will attempt to send the packet. For example, if this register is set to 7, the Slave will choose a number between one and seven as the next slot in which to transmit. Suppose the random number generator picks 5, then the Slave will transmit in the fifth time slot. A Slave will transmit a maximum of once per hopping interval, however, depending on the duration of the hopping interval and the maximum packet size, more than one slot per hop is potentially available. The Slave will transmit more frequently when a Repeat Interval with a smaller range is selected. Choose 1 to have the Slave transmit in the first available slot. Choose higher intervals for less frequent transmission, or to avoid collisions between many Slaves in the system.

AT Menu

Link Handshaking S122 P

Link Handshaking is controlled only by the Master unit. If the Master runs out of free buffers, it will command all Slaves and Repeaters to hold their data. Once the Master is ready to receive data it will allow the Slaves and Repeaters to transmit. Possible values are ‘1’ - Enabled and ‘0’ - Disabled. The default is 1. This register is ignored by all Slave and Repeater units.

AT Menu

Modbus Mode S117 Q

Modbus Mode allows for the CompactRFTM to be fully Modbus compatible. Please contact Microhard Systems for assistance when configuring the unit for Modbus operation. Optimal Modbus settings rely on several other S Register parameters.

The allowable settings for this register are:

*0 Disabled

1 Enabled

32 CompactRFTM Operating Manual: Chapter4 Configuration

AT Menu

RTS/DCD Framing 120 R

DCD Timeout 121 S

The CompactRFTM supports two special types of data framing:

• Input (or RTS/CTS) Data Framing; and,

• Output (or DCD) Data Framing

Input Data Framing is enabled by configuring the Handshaking Parameter as &K2. This type of framing makes use of the S120 parameter as illustrated in Figure 9. Parameter S120 can be set to any value between 0 and 254 ms.

RTS

CTS

TXD

S120 (ms)

Data going into MHX-910

0 to 1 ms

Figure 9 - Input Data Framing

To enable output (DCD) data framing, set the Data Carrier Detect parameter as &C2. This type of framing uses both S120 and S121 registers as shown in Figure 10. Valid ranges for each parameter are 0 to 254 ms.

DCD

RXD

S120 (ms) S121 (ms)

Figure 10 - Output Data Framing

Data leaving MHX-910

AT Menu

RSSI Reading S123 T

This register displays the average signal strength in dBm over the previous four hop intervals. Valid RSSI readings apply only to units configured as Slave or Repeater.

CompactRFTM Operating Manual: Chapter 4 Configuration 33

34 CompactRFTM Operating Manual: Chapter4 Configuration

The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals.

5. Installation

The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals.

The CompactRF complies with FCC part 15 at the modular level for operation in the license-free 902-928 MHz ISM band. This chapter provides guidelines for installing and deploying equipment which incorporates the CompactRF module.

5.1 Estimating the Gain Margin

Successful communication between CompactRF modules is dependent on three main factors:

• System Gain

• Path Loss

• Interference

System gain is a calculation in dB describing the performance to be expected between a transmitter-receiver pair. The number can be calculated based on knowledge of the equipment being deployed. The following four factors make up a system gain calculation:

1. Transmitter power (user selectable 0, 10, 20 or 30 dBm)

2. Transmitter gain (transmitting antenna gain minus cabling loss between

the transmitting antenna and the CompactRF module)

3. Receiver gain (Receiving antenna gain minus cabling loss between the

receiving antenna and the module)

4. Receiver sensitivity (Specified as -103 dBm on the CompactRF

module)

In the following illustration, the transmitting antenna has a gain of 6 dB, and the receiving antenna has a gain of 3 dB. The cable loss between the module and the antenna is 2 dB on both the transmitting and receiving side.

Cable Loss = 2 dB

Transmitter

30 dBm

Output Power

Antenna Gain = 6 dB Antenna Gain = 3 dB

Cable Loss = 2 dB

Receiver

Sensitivity =

-103 dBm

The power level has been set to 30 dBm (1W) on the transmitter, and the receiver sensitivity for the CompactRF is -103 dBm.

System gain would be calculated to be: 30 - 2 + 6 + 3 - 2 + 103 = 138 dB.

CompactRFTM Operating Manual: Chapter 5 Installation 35

Base Height (m)

Mobile

Height

(m)

When deploying your system, care must be taken to ensure the path loss (reduction of signal strength from transmitter to receiver in dB) between equipment does not exceed the system gain (138 dB in the above example). It is recommended to design for a gain margin of at least 10 dB to ensure reliable communication. Gain margin is the difference between system gain and path loss. Referring to the same example, if the path loss is 100 dB, the gain margin would be 38 dB, which is more than adequate for reliable communication.

Path loss is a very complicated calculation which mainly depends on the terrain profile, and the height of the antennas off the ground.

Distance (km)

The following table provides path loss numbers for varying antenna heights and antenna separation: These numbers are real averages taken from rural environments. They do not apply to urban, non-line-of-sight environments.

Distance

(km)

Base Height

(m)

Mobile Height

(m)

Path Loss

(dB)

5 15 2.5 116.5 5 30 2.5 110.9 8 15 2.5 124.1 8 15 5 117.7

8 15 10 105 16 15 2.5 135.3 16 15 5 128.9 16 15 10 116.2 16 30 10 109.6 16 30 5 122.4 16 30 2.5 128.8

Once the equipment is deployed, you can verify the signal strength by entering into Command Mode and reading Register S123. This register provides the average signal strength in dBm. The minimum strength for communication is roughly -103 dBm. For consistent reliable communication, you should try to deploy the equipment such that signal strength exceeds -95 dBm.

36 CompactRFTM Operating Manual: Chapter 5 Installation

5.2 Antennas and Cabling

This section describes the recommended procedure for installing cabling and antennas for use with the CompactRF module.

5.2.1 Internal Cabling

The most common method for installing the module is to run a cable from the module’s SMA connector to an N-male bulkhead connector on the chassis of the equipment as shown in Figure 11

N-male connector

LMR195 Cable

with SMA male

connector

and N-male

bulkhead

connector

SMA male connector

Figure 11. Suggested Internal Cabling

With losses of 10.7 dB/100ft, LMR195 is a high quality cable ideal for use with the CompactRF’s SMA connector. Losses are negligible for the short piece used within the chassis. Additional losses up to 0.5 dB may be present in the SMA and N connections.

CompactRFTM Operating Manual: Chapter 5 Installation 37

The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals.

5.2.2 Installing External Cables, Antennas and Lightning Arrestors

The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals.

Never work on an antenna system when there is lightning in the area. Direct human contact with the antenna is potentially unhealthy when the

CompactRF is generating RF energy. Always ensure that the CompactRF equipment is powered down during installation.

Never work on an antenna system when there is lightning in the area.

Direct human contact with the antenna is potentially unhealthy when the CompactRF is generating RF energy. Always ensure that the CompactRF equipment is powered down during installation.s

Surge Arrestors The most effective protection against lightning is to install two lightning

(surge) arrestors. One at the antenna, and the other at the interface with the equipment. The surge arrestor grounding system should be fully interconnected with the transmission tower and power grounding systems to form a single, fully integrated ground circuit. Typically, both ports on surge arrestors are N-female.

Cabling The following coax cables are recommended:

Cable Loss (dB/100ft)

LMR 195 10.7 LMR 400 3.9 LMR 600 2.5

Factors to take into consideration when choosing a cable are:

• price;

• bend radius limitations (the lower performance cables generally can

bend more sharply)

• performance requirements; and,

• distance between the equipment and the antenna.

When installing the cable, always begin fastening at the top near the antenna connector/surge arrestor. The cable must be supported at the top with a hose clamp or wrap lock, and at 5 ft intervals down the length of the tower. Over-tightening the fasteners will dent the cable and reduce performance. If properly grounded surge arrestors are not installed at both the top and the bottom of the cable, then the cable should be grounded to the tower at these locations using a cable grounding kit. If the tower is non-conductive, then a separate conductor, physically separate from the cable, should be run down the tower.

38 CompactRFTM Operating Manual: Chapter 5 Installation

Antenna Before choosing an antenna, you should have some knowledge of the path

loss and the topology of the equipment. If the equipment is in a fixed location and is to communicate with only one other unit also in a fixed location, then a Yagi antenna is suitable. Choose a Yagi with enough gain to ensure adequate gain margin. When deploying the Yagi, point the antenna towards the intended target, ensuring the antenna elements are perpendicular to the ground.

If the equipment must communicate with multiple or mobile transceivers, then select an Omni-directional antenna with appropriate gain.

The Effective Radiated Power (ERP) emitted from the antenna cannot exceed +36 dBm ERP.

To comply with FCC regulations, .you must limit ERP to 36 dBm or less.

With the CompactRF set to full power, ERP is calculated as follows: ERP = 30 - (Cabling and Connector Losses) + (Antenna Gain) < 36 Use the guidelines in the previous section for calculating cable and

connector losses. If cabling and connector losses are 2 dB, then the maximum allowable gain of the antenna will be 8 dB.

External Filter Although the CompactRF is capable of filtering out RF noise in most

environments, there are occasions that require external filtering. Paging towers, and cellular base stations in close proximity to the CompactRF antenna can desensitize the receiver. Microhard Systems’ external cavity filter eliminates this problem. The filter has two N-female ports and should be connected in line at the interface to the RF equipment.

Weatherproofing Type N connectors are not weatherproof. All connectors should be taped

with rubber splicing tape (weatherproofing tape), and then coated with a sealant.

CompactRFTM Operating Manual: Chapter 5 Installation 39

40 CompactRFTM Operating Manual: Chapter 5 Installation

A. Modem Command Summary

The following provides a command summary for the CompactRFTM. Factory settings are denoted with a ‘*’.

AT Commands

A Answer E Command Echo

E0 No Echo * E1 Command Echo

I Identification

I0 Product Code I2 ROM Checksum test I3 Firmware Version I4 Firmware Date I5 Copyright

I6 Firmware Time O On-line Mode Q Quiet Mode

* Q0 Enables Result Codes

Q1 Disables Result Codes V Result Codes Display

V0 Display as Numbers

* V1 Display as Words W Connection Result

* W0 Reports DTE as CONNECT xxxx

W1 Reports computer (DTE) rate and wireless rate

between modems as CARRIER xxxx.

W2 Reports DCE as CONNECT xxxx Z Reset and load stored configuration &C DCD (Data Carrier Detect)

&C0 DCD is always on

* &C1 DCD is on when modems are synchronized

&C2 DCD used for output data framing &D DTR (Data Terminal Ready)

&D0 DTR ignored

* &D2 DTR disconnects and switches to command

&D3 DTR disconnects and resets modem &F Load Factory Default

&F1 Master

&F2 Slave

&F3 Repeater

&F4 Slave through Repeater &K Handshaking

&K0 Disable Handshaking

&K2 RTS/CTS Input Framing

* &K3 Enable Handshaking &S DSR (Data Set Ready)

&S0 DSR is always on

* &S1 DSR on in data, off in command mode &V View Configuration &W Write configuration to memory Sxx? Read S register value Sxx=yy Set S register value

Result Codes

0 OK 12 CONNECT 9600 3 NO CARRIER 13 CONNECT 14400 4 ERROR 14 CONNECT 19200 7 CONNECT 2400 15 CONNECT 28800 8 CONNECT 3600 17 CONNECT 38400 9 CONNECT 4800 18 CONNECT 57600 10 CONNECT 7200 33 CONNECT 115200 64 CARRIER 20000 62 CARRIER 45000

S Registers

S0 Auto Answer [0...255]

0 = power up in Command Mode,

non-zero = power up in Data Mode S2 Escape code [0...255] default ‘+’ S3 CR character [0...255] default <cr> S4 Line Feed [0...255] default <lf> S5 Backspace [0...255] default <bs> S101 Operating Mode

1 - Master Point to Multipoint

2 - Master Point to Point

3 - Slave

4 - Repeater S102 Serial Baud Rate

*1 = 115200, 2 = 57600, 3 = 38400

4 = 28800, 5 = 19200, 6 = 14400

7 = 9600, 8 = 7200, 9 = 4800,

10 = 3600, 11 = 2400 S103 Wireless Link Rate

2 = Fast w/o FEC

*4 = Fast with FEC S104 Network Address [0...65535] S105 Unit Address [1...65535] S106 Primary Hopping Pattern [0...61] S206 Secondary Hopping Pattern [0...61] S107 Encryption Key [0...65535] S108 Output Power Level

0 = 1 mW, 1 = 10 mW, *2 = 100 mW

3 = 1000 mW S109 Hopping Interval

1 = 8 msec, 2 = 12 msec, 3 = 16 msec,

4 = 20 msec, 5 = 30 msec, 6 = 45 msec,

7 = 80 msec, *8 = 120 msec S110 Data Format

* 1 = 8N1, 2 = 8N2, 3 = 8E1, 4 = 8O1

5 = 7N1, 6 = 7N2, 7 = 7E1, 8 = 7O1

9 = 7E2, 10 = 7O2, 11 = 9N1 S111 Packet Minimum Size [1...Maximum Size] S112 Packet Maximum Size [2...255] S113 Packet Retransmissions [0...255] S213 Packet Retry Limit [0...255] S115 Packet Repeat Interval [1..255]

Default = 1 S116 Packet Character Timeout [0...254 ms] S117 Modbus Mode

*0 = Disabled, 1 = Enabled S120 RTS/DCD Framing Interval [0...254 ms] S121 DCD Timeout [0...254 ms] S122 Link Handshaking [0=Disabled, *1=Enabled]

CompactRFTM Operating Manual: Appendix A Modem Command Summary 41

42 CompactRFTM Operating Manual: Appendix A Modem Command Summary

Modem

Signal

DCD

RX TX

DTR

SG DSR RTS CTS

Microprocessor

→ →   → →  →

(DCE)



←



←



Arrows denote the direction that signals are asserted (e.g., DCD originates at the DCE and tells the DTE that a carrier is present).

Host

(DTE)

IN OUT OUT

IN OUT

B. Serial Interface

The CompactRFTM uses 8 pins on its 36 pin header for asynchronous serial I/O. The interface conforms to standard RS-232.

The signals in the asynchronous serial interface are described below:

DCD Data Carrier Detect - Output from Module - When asserted (positive

voltage), DCD informs the DTE that a communications link has been established with another CompactRFTM.

RXD Receive Data - Output from Module - Signals transferred from the

CompactRFTM are received by the DTE via RX.

TXD Transmit Data - Input to Module - Signals are transmitted from the DTE

via TX to the CompactRFTM.

DTR Data Terminal Ready - Input to Module - Asserted by the DTE to inform

the modem that it is alive and ready for communications.

SG Signal Ground - Provides a ground reference for all signals transmitted by

both DTE and DCE.

DSR Data Set Ready - Output from Module - Asserted by the DCE to inform

the DTE that it is alive and ready for communications. DSR is the modem’s equivalent of the DTR signal.

RTS Request to Send - Input to Module - A “handshaking” signal which is

asserted by the DTE when it is ready. When hardware handshaking is used, the RTS signal indicates to the DCE that the host can receive data.

CTS Clear to Send - Output from Module - A “handshaking” signal which is

asserted by the DCE when it has enabled communications and transmission from the DTE can commence. When hardware handshaking is used, the CTS signal indicates to the host that the DCE can receive data.

Notes: It is typical to refer to RXD and TXD from the perspective of the DTE. This should

be kept in mind when looking at signals relative to the modem (DCE); the modem transmits data on the RXD line, and receives on TXD.

“DCE” and “modem” are often synonymous since a modem is typically a DCE device. “DTE” is, in most applications, a device such as a host microprocessor.

CompactRFTM Operating Manual: Serial Interface 43

44 CompactRFTM Operating Manual: Appendix B Serial Interface

C. Factory Default Settings

AT&F1 - Master Default Settings

E1, Q0, V1, W0, S0=0, S2=43, S3=13, S4=10, S5=8 DCD &C1 (On)

DTR &D0 (DTR is ignored) Framing &E0 (Disabled) Handshaking &K3 (Enabled) DSR &S1 (On in Data, Off in Command) Operating Mode S101=1 (Master P-MP) Serial Baud Rate S102=1 (115kbaud) Wireless Link Rate S103=4 (Fast, FEC) Network Address S104=1 Unit Address S105=1 Primary Hop Pattern S106=0 Encryption Key S107=1 Output Power S108=2 (100mW) Hop Interval S109=8 Data Format S110=1 (8N1) Packet Minimum Size S111=1 Packet Maximum Size S112=255 Packet Retransmissions S113=2 Link Handshaking S122=1 (Enabled) Packet Repeat Interval S115=1 (Don’t Care) Character Timeout (ms) S116=8 Modbus Mode S117=0 RTS/DCD Framing (ms) S120=0 DCD Timeout (ms) S121=0 Secondary Hop Pattern S206=2 (Don’t Care) Packet Retry Limit S213=2 (Don’t Care)

AT&F2 - Slave Default Settings

E1, Q0, V1, W0, S0=1, S2=43, S3=13, S4=10, S5=8 DCD &C1 (On when modems are synced)

DTR &D0 (DTR is ignored) Framing &E0 (Disabled) Handshaking &K3 (Enabled) DSR &S1 (On in Data, Off in Command) Operating Mode S101=3 (Slave) Serial Baud Rate S102=1 (115kbaud) Wireless Link Rate S103=4 (Fast, FEC) (Set by Master) Network Address S104=1 Unit Address S105=2 Primary Hop Pattern S106=0 Encryption Key S107=1 Output Power S108=2 (100mW) Hop Interval S109=8 (Set by Master) Data Format S110=1 (8N1) Packet Minimum Size S111=1 (Set by Master) Packet Maximum Size S112=255 (Set by Master) Packet Retransmissions S113=2 (Don’t Care) Link Handshaking S122=1 (Enabled) (Set by Master) Packet Repeat Interval S115=1 Character Timeout (ms) S116=9 Modbus Mode S117=0 RTS/DCD Framing (ms) S120=0 DCD Timeout (ms) S121=0 Secondary Hop Pattern S206=2 (Don’t Care) Packet Retry Limit S213=2

AT&F3 - Repeater Default Settings

E1, Q0, V1, W0, S0=1, S2=43, S3=13, S4=10, S5=8 DCD &C1 (On when modems are synced)

DTR &D0 (DTR is ignored) Framing &E0 (Disabled) Handshaking &K3 (Enabled) DSR &S1 (On in Data, Off in Command) Operating Mode S101=4 (Repeater) Serial Baud Rate S102=1 (115kbaud) Wireless Link Rate S103=4 (Fast, FEC) (Set by Master) Network Address S104=1 Unit Address S105=3 Primary Hop Pattern S106=0 Encryption Key S107=1 Output Power S108=2 (100mW) Hop Interval S109=8 (Set by Master) Data Format S110=1 (8N1) Packet Minimum Size S111=1 (Set by Master) Packet Maximum Size S112=255 (Set by Master) Packet Retransmissions S113=2 Link Handshaking S122=1 (Enabled) (Set by Master) Packet Repeat Interval S115=1 Character Timeout (ms) S116=8 Modbus Mode S117=0 RTS/DCD Framing (ms) S120=0 DCD Timeout (ms) S121=0 Secondary Hop Pattern S206=2 Packet Retry Limit S213=2

AT&F4 -Slave Through Repeater Default Settings

E1, Q0, V1, W0, S0=1, S2=43, S3=13, S4=10, S5=8 DCD &C1 (On when modems are synced)

DTR &D0 (DTR is ignored) Framing &E0 (Disabled) Handshaking &K3 (Enabled) DSR &S1 (On in Data, Off in Command) Operating Mode S101=3 (Slave) Serial Baud Rate S102=1 (115kbaud) Wireless Link Rate S103=4 (Fast, FEC) (Set by Master) Network Address S104=1 Unit Address S105=4 Primary Hop Pattern S106=2 Encryption Key S107=1 Output Power S108=2 (100mW) Hop Interval S109=8 (Set by Master) Data Format S110=1 (8N1) Packet Minimum Size S111=1 (Set by Master) Packet Maximum Size S112=255 (Set by Master) Packet Retransmissions S113=2 (Don’t Care) Link Handshaking S122=1 (Enabled) (Set by Master) Packet Repeat Interval S115=1 Character Timeout (ms) S116=8 Modbus Mode S117=0 RTS/DCD Framing (ms) S120=0 DCD Timeout (ms) S121=0 Secondary Hop Pattern S206=2 (Don’t Care) Packet Retry Limit S213=2

CompactRFTM Operating Manual: Appendix C. Factory Default Settings 45

46 CompactRFTM Operating Manual: Appendix C Factory Default Settings

D. Performance Tables

The scope of this appendix is to find the best possible performance and maximum packet size at different modes of operation. The setup assumes a baud rate of 115k, no retries and no retransmissions..

Hop

Interval 1 (8 ms)

Master to Slave 2 (12 ms)

Communication. 3 (16 ms)

(No Repeater) 4 (20 ms)

5 (30 ms)

Link Rate = Fast 6 (45 ms)

NO FEC 7 (80 ms)

8 (120 ms)

1 (8 ms)

Master to Slave 2 (12 ms)

Communication. 3 (16 ms)

(No Repeater) 4 (20 ms)

5 (30 ms)

Link Rate = Fast 6 (45 ms)

WITH FEC 7 (80 ms)

8 (120 ms)

1 (8 ms)

Master to 2 (12 ms)

Repeater Direct 3 (16 ms)

Communication. 4 (20 ms)

5 (30 ms)

Link Rate = Fast 6 (45 ms)

NO FEC 7 (80 ms)

8 (120 ms)

1 (8 ms)

Master to 2 (12 ms)

Repeater Direct 3 (16 ms)

Communication. 4 (20 ms)

5 (30 ms)

Link Rate = Fast 6 (45 ms)

WITH FEC 7 (80 ms)

8 (120 ms)

1 (8 ms) Master to Slave 2 (12 ms) Through One or 3 (16 ms)

More Repeaters. 4 (20 ms)

5 (30 ms)

Link Rate = Fast 6 (45 ms)

NO FEC 7 (80 ms)

8 (120 ms)

1 (8 ms) Master to Slave 2 (12 ms) Through One or 3 (16 ms)

More Repeaters. 4 (20 ms)

5 (30 ms)

Link Rate = Fast 6 (45 ms)

WITH FEC

7 (80 ms)

8 (120 ms)

Optimal Packet

Size (bytes)

14 20

66 52 110 66 154 74 255 83 255 56 255 31 255 21

5 4 34 22 54 28 76 32

130 38 210 43 255 30 255 20

N/A N/A

3 1 22 13 44 21

101 32 178 39 255 31

255 21 N/A N/A N/A N/A

5 2 16 6 43 12 80 16

174 20 255 20

N/A N/A

3 1 22 13 43 21 93 31

174 38 255 31

255 21 N/A N/A N/A N/A N/A N/A

14 6 40 12 80 16

174 19 255 20

Throughput

(kbps)*

CompactRFTM Operating Manual: Appendix D. Performance Tables 47

48 CompactRFTM Operating Manual: Appendix D. Performance Tables

50 CompactRFTM Operating Manual:

F. Technical Specifications

Electrical/Physical

Data Interface Asynchronous Serial Port, TTL Levels Signals Sig. Gnd, TX, RX, DCD, DSR, DTR, RTS, CTS Baud rate 2,400 - 19200 bps, (user-selectable)

Up to 19200 full-duplex sustained throughput Communications Range Voltage Requirements 4.75 to 5.5 VDC, 1.0 Amp Current Consumption Rx: 85mA;

Operating Frequency 902 - 928 MHz System Gain 133 dB Sensitivity -103 dBm Output Power 1mW, 10mW, 100mW, 1W (user-selectable) Spreading Code Frequency Hopping Hopping Patterns 35 pseudo-random, user-selectable Error Detection CRC-16 with auto re-transmit

16 kilometres (10 miles)

Tx 1mW: 100mA;

Tx 10mW: 132mA;

Tx 100mW: 231mA;

Tx 1W: 600mA;

Sleep: <1.5mA

Memory Non-volatile configuration memory Dimensions (LxWxH) Weight Approx. 20 grams Operating Environment Temperature: -25 to +70°C

Storage Temperature -40 to 90°C

1. Clear line-of-sight, elevated antennas.

Approx. 2.0” x 1.5” x 0.375”

Humidity: 5 to 95%, non-condensing

CompactRFTM Operating Manual: Appendix F. Technical Specifications 51

52 CompactRF

Operating Manual: Appendix F. Technical Specifications

G. Development Board Schematics

Schematics begin on next page.

CompactRFTM Operating Manual: Appendix G. Development Board Schematics 53

54 CompactRF

Operating Manual: Appendix G. Development Board Schematics

CompactRFTM Operating Manual: Appendix G. Development Board Schematics 55

56 CompactRF

Operating Manual: Appendix G. Development Board Schematics

CompactRFTM Operating Manual: Appendix G. Development Board Schematics 57

58 CompactRF

Operating Manual: Appendix H. Mechanical Drawing

H. Mechanical Drawing

Dimensions in thousandths of an inch.

Shaded areas = keep clear. Microhard Systems Inc.

330

375

1500

19 36

Top View

CompactRF Mechanical Drawing

Size A Document Number: D1043-02 Drawn By: NB Sheet 1 of 1

Wednesday, July 26, 2000

78.7 (2mm)

525

225

1245

200

2000

78.7 (2mm)

Pin 1

dia. 64

410

Recommended Footprint

Drill Size = 32 mil

110, 1144 - 29th Avenue N.E..

Calgary, Alberta, Canada

T2E 7P1

500

Rev.

CompactRFTM Operating Manual: Appendix H. Mechanical Drawing 59

1245

60 CompactRF

Operating Manual: Appendix H. Mechanical Drawing

I. Glossary

Terminology Used in the CompactRFTM Operating Manual

Asynchronous communications A method of

telecommunications in which units of single bytes of data are sent separately and at an arbitrary time (not periodically or referenced to a clock). Bytes are “padded” with start and stop bits to distinguish each as a unit for the receiving end, which need not be synchronized with the sending terminal.

Attenuation The loss of signal power through

equipment, lines/cables, or other transmission devices. Measured in decibels (dB).

Bandwidth The information-carrying capacity of a

data transmission medium or device, usually expressed in bits/second (bps).

Baud Unit of signaling speed equivalent to the

number of discrete conditions or events per second. If each signal event represents only one bit condition, then baud rate equals bits per second (bps) – this is generally true of the serial data port, so baud and bps have been used interchangeably in this manual when referring to the serial port; this is not always the case during the DCE-to-DCE communications, where a number of modulation techniques are used to increase the bps rate over the baud rate.

Bit The smallest unit of information in a binary

system, represented by either a 1 or 0. Abbreviated “b”.

Bits per second (b/s or bps) A measure of data

transmission rate in serial communications. Also see baud.

Byte A group of bits, generally 8 bits in length. A

byte typically represents a character of data. Abbreviated “B”.

Characters per second (cps) A measure of data

transmission rate for common exchanges of data. A character is usually represented by 10 bits: an 8bit byte plus two additional bits for marking the start and stop. Thus, in most cases (but not always), cps is related to bits per second (bps) by a 1:10 ratio.

CRC (Cyclic Redundancy Check) An error-detection

scheme for transmitted data. Performed by using a polynomial algorithm on data, and appending a checksum to the end of the packet. At the

receiving end, a similar algorithm is performed and checked against the transmitted checksum.

Crossover cable (Also known as rollover, null-

modem, or modem-eliminator cable) A cable which allows direct DTE-to-DTE connection without intermediate DCEs typically used to bridge the two communicating devices. Can also be used to make cabled DCE-to-DCE connections. The name is derived from “crossing” or “rolling” several lines, including the TX and RX lines so that transmitted data from one DTE is received on the RX pin of the other DTE and vice-versa.

Data Communications Equipment (DCE, also

referred to as Data Circuit-Terminating Equipment, Data Set) A device which facilitates a communications connection between Data Terminal Equipment (DTEs). Often, two or more compatible DCE devices are used to “bridge” DTEs which need to exchange data. A DCE performs signal encoding, decoding, and conversion of data sent/received by the DTE, and transmits/receives data with another DCE. Common example is a modem.

Data Terminal Equipment (DTE) An end-

device which sends/receives data to/from a DCE, often providing a user-interface for information exchange. Common examples are computers, terminals, and printers.

dBm Stands for “Decibels referenced to one

milliwatt (1 mW)”. A standard unit of power level commonly used in RF and communications work. n dBm is equal to 10 0dBm = 1mW, -10dBm = 0.1mW, -20dBm =

0.01mW, etc.

DCE See Data Communications Equipment. DTE See Data Terminal Equipment. Flow Control A method of moderating the

transmission of data so that all devices within the communications link (DTEs and DCEs) transmit and receive only as much data as they can handle at once. This prevents devices from sending data which cannot be received at the other end due to conditions such as a full buffer or hardware not in a ready state. This is ideally handled by hardware using flow-control and handshaking signals, but

(n/10)

milliwatt, so

CompactRFTM Operating Manual: Appendix I. Glossary 61

can be controlled also by software using X-ON/XOFF (transmitter on/off) commands.

Frequency-hopping A type of spread spectrum

communication whereby the carrier frequency used between transmitter and receiver changes repeatedly in a synchronized fashion according to a specified algorithm or table. This minimizes unauthorized jamming (interference) and interception of telecommunications.

Full-duplex Where data can be transmitted,

simultaneously and independently, bidirectionally.

Half duplex Exists when the communications

medium supports bi-directional transmission, but data can only travel in one direction at the same time.

Handshaking A flow-control procedure for

establishing data communications whereby devices indicate that data is to be sent and await appropriate signals that allow them to proceed.

Line-of-sight Condition in which a transmitted

signal can reach its destination by travelling a straight path, without being absorbed and/or bounced by objects in its path.

Master The station which controls and/or polls one

or more Slave stations in a point-to-point or pointto-multipoint network. Often functions as a server or hub for the network.

Non-volatile memory Memory which retains

information which is written to it.

Null modem cable See Crossover cable. Point-to-point A simple communications network

in which only two DTEs are participants.

Point-to-multipoint A communications network

in which a Master DTE communicates with two or more Slave DTEs.

Repeater A device which automatically amplifies

or restores signals to compensate for distortion and/or attenuation prior to retransmission. A repeater is typically used to extend the distance for which data can be reliably transmitted using a particular medium or communications device.

RS-232 (Recommended Standard 232; more

accurately, RS-232C or EIA/TIA-232E) Defined by the EIA, a widely known standard electrical and physical interface for linking DCEs and DTEs for serial data communications. Traditionally specifies a 25-pin D-sub connector, although

many newer devices use a compact 9-pin connector with only the essential signaling lines used in asynchronous serial communications. Lines have two possible states: “high” (on, active, asserted, carrying +3 to +25 V) or “low” (off, inactive, disasserted, carrying -3 to -25 V).

RTU (Remote Terminal Unit) A common term

describing a DTE device which is part of a widearea network. Often a RTU performs data I/O and transmits the data to a centralized station.

Serial communications A common mode of

data transmission whereby character bits are sent sequentially, one at a time, using the same signaling line. Contrast with parallel communications where all bits of a byte are transmitted at once, usually requiring a signal line for each bit.

Shielded cable Interface medium which is

internally shrouded by a protective sheath to minimize external electromagnetic interference (“noise”).

Slave A station which is controlled and/or polled by

the Master station for communications. Typically represents one end of a point-to-point connection, or one of the terminal nodes in a point-tomultipoint network. Often a RTU is linked by a Slave DCE.

Spread spectrum A method of transmitting a

signal over a wider bandwidth (using several frequencies) than the minimum necessary for the originally narrowband signal. A number of techniques are used to achieve spread spectrum telecommunications, including frequency hopping. Spread spectrum provides the possibility of sharing the same band amongst many users while increasing the tolerance to interference and noise, and enhancing privacy of communications.

Throughput A measure of the rate of data trans-

mission passing through a data communication system, often expressed as bits or characters per second (bps or cps).

62 CompactRFTM Operating Manual: Appendix I. Glossary

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