Intuicom Communicator II User manual

Intuicom, Inc.
1880 S Flatiron Court
Boulder, CO 80301
[phone]
www.intuicom.com
Intuicom®
Communicator IITM
Spread Spectrum Wireless Data Transceiver
User Guide

Communicator II User Guide
This manual is for use by purchasers and other authorized users of the IntuicomProducts. No
part of this document may be reproduced or transmitted in any form or by any means, electronic
or mechanical, or for any purpose without the express written permission of Intuicom Inc.
© 2000 - 2003 Intuicom Incorporated. All rights reserved.
Intuicom reserves the right to make changes to this manual without notice. Unless otherwise
agreed to in writing, Intuicom assumes no responsibility or liability for the use of this manual or
for the infringement of any copyright or other proprietary right and Intuicom shall deem nothing
contained in this manual a warranty or guarantee.
Intuicom, WiGate, Nav-Link, TargeTracker, Intuicom Communicator, Intuicom SmartGPS
Tracker/Surveyor, Intuicom SmartGPS Navigator, Intuicom Navigator II and Intuicom
Communicator II are trade names of Intuicom, Inc.
Other product names mentioned in this manual may be copyrights, trademarks, or registered
trademarks of their respective companies and are hereby acknowledged.
Revision 1.0c i © 2003 Intuicom Inc.

Communicator II User Guide
This product is licensed by The United States.
Diversion contrary to U.S. law is prohibited.
Shipment or re-export of this product outside of The
United States may require authorization by the U.S.
Bureau of Export Administration. Please contact
Intuicom, Inc. for assistance and further information.
Revision 1.0c ii © 2003 Intuicom Inc.

Communicator II User Guide
Table of Contents
1Product Overview ................................................................................................................. 1
1.1 Communicator II roles in Intuicom Wireless Data Networks......................................... 1
2Quick Start ............................................................................................................................ 2
3Quick Start on a Multipoint System ................................................................................... 3
3.1 0) Set Operation Mode.................................................................................................... 3
3.2 1) Set Baud Rate.............................................................................................................. 3
3.3 3) Edit Radio Transmission Characteristics................................................................... 3
3.4 4) Edit Multipoint Parameters........................................................................................ 3
4Tuning Transceiver Performance ....................................................................................... 4
5Operation Mode Selections (Main Menu Option 0)........................................................... 6
5.1 (0) Point-to-Point Master ............................................................................................... 6
5.2 (1) Point-to-Point Slave .................................................................................................. 7
5.3 (2) Point-to-Multipoint Master ....................................................................................... 7
5.4 (3) Point-to-Multipoint Slave.......................................................................................... 7
5.5 (4) Point-to-Point Slave/Repeater................................................................................... 7
5.6 (5) Point-to-Point Repeater ............................................................................................ 8
5.7 (6) Point-to-Point Slave/Master Switchable ................................................................... 8
5.8 (7) Point-to-Multipoint Repeater .................................................................................. 11
5.9 TDMA (If TDMA firmware option installed)................................................................ 11
5.10 (F) Ethernet options...................................................................................................... 11
6Multipoint Operation.......................................................................................................... 12
6.1 Theory of Operation...................................................................................................... 12
6.2 Installing Multipoint Systems........................................................................................ 12
6.3 Overlapping Multipoint Systems................................................................................... 13
6.4 Setting Multipoint Parameters (Main Menu Option 5)................................................. 13
6.4.1 (0) Number Repeaters........................................................................................... 13
6.4.2 (1) Master Packet Repeat...................................................................................... 13
6.4.3 Master Packet Repeat in Multipoint Systems with Repeaters .............................. 14
6.4.4 (2) Max Slave Retry and (3) Retry Odds.............................................................. 15
6.4.5 (4) DTR Connect................................................................................................... 16
6.4.6 (5) Repeater Frequency......................................................................................... 16
6.4.7 (6) NetWork ID..................................................................................................... 16
6.4.8 (8) MultiMaster Synch.......................................................................................... 16
6.4.9 (9) 1 PPS Enable/Delay ........................................................................................ 16
6.4.10 (A) Slave/Repeater................................................................................................ 17
6.4.11 (B) Diagnostics ..................................................................................................... 17
6.4.12 (C) Subnet ID........................................................................................................ 18
6.4.13 (D) Radio ID ......................................................................................................... 20
7Baud Rate (Main Menu Option 1)..................................................................................... 21
7.1 (0-9) Set Baud Rate...................................................................................................... 21
7.2 (A) Data Word Length and Parity ................................................................................ 22
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Communicator II User Guide
7.3 (B) ModBus RTU........................................................................................................... 22
7.4 (C) RS232/485............................................................................................................... 22
7.5 (D) Setup Port............................................................................................................... 23
7.6 (E) Turn on/off delay..................................................................................................... 23
7.7 (F) Flow Control........................................................................................................... 24
8Call Book (Main Menu Option 2)...................................................................................... 25
8.1 Entering or Modifying numbers in the Call Book......................................................... 26
8.2 Programming the Call Book to Use 3 or 4 Repeaters .................................................. 26
8.3 Programming The Call Book in Multipoint Systems .................................................... 28
9Radio Parameters (Main Menu Option 3)........................................................................ 29
9.1 (0) FreqKey................................................................................................................... 29
9.2 (0) Hop Table Version .................................................................................................. 31
9.2.1 (1) Hop Table Size................................................................................................ 31
9.2.2 (2) Hop Freq Offset............................................................................................... 31
9.2.3 Additional Frequency information for 2.4GHz transceivers ................................ 31
9.3 (1,2) Max Packet Size and Min Packet Size.................................................................. 33
9.4 (3) Xmit Rate................................................................................................................. 35
9.5 (4) RF Data Rate........................................................................................................... 35
9.6 (6) Slave Security .......................................................................................................... 36
9.7 (7) RTS to CTS .............................................................................................................. 36
9.8 (8) Retry Time Out ........................................................................................................ 37
9.9 (9) Lowpower Mode...................................................................................................... 37
9.10 (A) High Noise .............................................................................................................. 38
9.11 (B) MCU speed ............................................................................................................. 38
10 Radio Statistics (Main Menu Option 4) ........................................................................ 39
10.1 Average Noise Level ..................................................................................................... 39
10.2 Average Signal Level .................................................................................................... 40
10.3 Overall Rcv Rate (%).................................................................................................... 40
10.4 Number of Disconnects................................................................................................. 40
10.5 Radio Temperature ....................................................................................................... 41
11 TDMA Menu (Main Menu Option 6) ........................................................................... 42
12 Password (Main Menu Option 8) .................................................................................. 43
12.1 Setting a Password........................................................................................................ 43
12.2 Changing a Password................................................................................................... 43
12.3 Disabling a Password................................................................................................... 43
13 Transceiver Location...................................................................................................... 44
14 Front Panel LEDs ........................................................................................................... 45
15 RS232 Pin Assignments .................................................................................................. 46
16 Establishing Data Communication Links..................................................................... 48
17 RS422 and RS485 Operation ......................................................................................... 52
18 Other Settings..................................................................................................................54
18.1 Baud Rate...................................................................................................................... 54
18.2 Setup Timeout................................................................................................................ 54
19 Technical Specifications ................................................................................................. 55
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Communicator II User Guide
19.1 900 Mhz Band Communicator II................................................................................... 55
19.2 2.4 Ghz Band Communicator II.................................................................................... 57
20 Enclosure Mechanical Drawing..................................................................................... 59
21 FCC Notification ............................................................................................................. 60
22 Warranty ......................................................................................................................... 61
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Communicator II User Guide
List of Tables
Table 4-1: Serial Settings to access Setup Menu............................................................................ 4
Table 5-1: Mode 6 Commands ....................................................................................................... 9
Table 6-1: Subnet ID Settings for example Multipoint Subnet Diagram ..................................... 19
Table 7-1: Data word length and parity selections ....................................................................... 22
Table 7-2: Data port protocol selections....................................................................................... 23
Table 7-3: Setup port selections.................................................................................................... 23
Table 7-4:Flow control selections................................................................................................. 24
Table 9-1: Frequency Bands 900 Mhz.......................................................................................... 31
Table 9-2: Frequency Band Selection 2.4 Ghz ............................................................................. 32
Table 9-3: Min Packet Size Settings (Bytes) ................................................................................ 34
Table 9-4: Max Packet Size Settings (Bytes) RF Data Rate 2...................................................... 34
Table 9-5: Max Packet Size Settings (Bytes) RF Data Rate 3...................................................... 35
Table 9-6: Low Power Settings..................................................................................................... 38
Table 9-7: MCU Speed Settings ................................................................................................... 38
Table 14-1: LED Status in Point-to-Point Mode .......................................................................... 45
Table 14-2: LED Status in Point-to-Multipoint Mode.................................................................. 45
Table 14-3: LED Status Legend ................................................................................................... 45
Table 15-1: Main RS232 Port Pinout............................................................................................ 46
Table 15-2: Diagnostics RS232 Port............................................................................................. 46
Table 15-3: Signal Definitions...................................................................................................... 47
Table 17-1: RS422 and RS485 Full Duplex Pinouts .................................................................... 53
Table 17-2: RS485 Half Duplex Pinout........................................................................................ 53
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Communicator II User Guide
Table of Figures
Figure 1-1: Intuicom Communicator II Front Panel....................................................................... 1
Figure 4-1: Setup Main Menu......................................................................................................... 5
Figure 5-1: Operation Mode Menu.................................................................................................6
Figure 5-2: Call Book Menu......................................................................................................... 10
Figure 6-1: Multipoint Parameters................................................................................................ 15
Figure 6-2: Multipoint Subnet Diagram ....................................................................................... 19
Figure 7-1: Baud Rate and other items related to the data port .................................................... 21
Figure 8-1: Call Book Menu......................................................................................................... 26
Figure 8-2: Calling a Slave Through 4 Repeaters......................................................................... 27
Figure 9-1: Radio Transmission Parameters Menu ...................................................................... 29
Figure 9-2: Hop Table Parameters................................................................................................ 30
Figure 9-3: Frequency Key and Hop Table Options 2.4 Ghz ....................................................... 33
Figure 10-1: Radio Statistics Menu .............................................................................................. 39
Figure 15-1: Communicator II Front Panel .................................................................................. 46
Figure 16-1: Point-to-Point no Repeater....................................................................................... 48
Figure 16-2: Point-to-Point with Repeater.................................................................................... 48
Figure 16-3: Point-to-Point with two Repeaters ........................................................................... 49
Figure 16-4: Point-to-Point with Slave/Repeaters ........................................................................ 49
Figure 16-5: Point-to-Multipoint network .................................................................................... 50
Figure 16-6: Point-to-Multipoint with Repeaters ......................................................................... 51
Revision 1.0c vii © 2003 Intuicom Inc.

Section 1: Product Overview
1 Product Overview
Welcome to the Intuicom Communicator II License-Free Spread-Spectrum Wireless Data
Transceiver. The Intuicom Communicator II can be used in a wide variety of roles to wirelessly
enable the flow of data to and from serial devices. Communicator II transceivers can be operated
in straightforward point-to-point or point-to-multipoint networks or in conjunction with Intuicom
Navigator II transceivers for highly functional Adaptive Multipoint networks combining multiple
serial ports and optional integrated GPS.
This User Guide covers basic setup and configuration of Intuicom Communicator II transceivers
and focuses on the most common mode of operation: Point-to-Multipoint.
SETUP
RADIO
MAIN DIAG CD
Communicator II
TX CTS -+
Figure 1-1: Intuicom Communicator II Front Panel
1.1 Communicator II roles in Intuicom Wireless Data Networks
While an Intuicom Navigator II can be used as a Master or a Repeater in an Intuicom
Multifunctional Adaptive Multipoint network, an Intuicom Communicator II often represents
a less costly option when Navigator II features are not required in these roles.
For more information about Intuicom Wireless Networks with Navigator II transceivers,
contact Intuicom.
Revision 1.0c 1 © 2003 Intuicom, Inc.

Section 2: Quick Start
2 Quick Start
When purchased as a pair the Intuicom®Communicator II Wireless Data Transceivers are
shipped from the factory pre-configured to operate together in point-to-point applications. The
Transceivers are preset for high-speed data communications and to communicate only with each
other.
Intuicom Communicator IIs will potentially operate in virtually any environment where RS232
data communications occur. The transceivers function as a 9-pin null modem cable. If the
Communicator II is to be used in an application where a null modem cable is used (such as
communication between two computers), then the transceivers can be connected directly. If the
transceivers are to be used to replace a straight-through RS232 cable, then a null modem cable or
adapter must be placed between the transceiver and the DCE instrument to which it is connected.
To establish communications between a pair of Intuicom Communicator II Wireless Data
Transceivers just received from the factory:
1. Set the baud rate on each transceiver to match the baud rate of the instrument to
which it is attached. Please note that when you are setting the transceiver's baud rate
you are setting its RS232 data rate, which must match the rate for the instrument to
which it is attached. This in turn means that the baud rate does not have to be on the
same setting for the two transceivers.
2. Verify that the RS232 connector on the cable supplied will fit the RS232 interface on
the instrument to which it is being connected. The cable supplied will fit a 9 pin male
RS232 connector; any other format will need an adapter or different cable.
3. Connect antennas to the transceivers. Any Communicator II transceiver may be
operated without an antenna for bench top testing without concern for damaging the
product.
4. Connect the transceiver to the instrument with the RS232 cable and attach the power
adapter to the transceiver. Shortly after both transceivers are plugged in they should
establish a communications link with each other and your connection is complete!
Note: The terms “Modem” and “Transceiver” are used interchangeably in this manual and in
the text of the setup menu. While the words have different meanings, the two terms should be
treated as one and the same for the purposes of use of the Intuicom product.
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Section 3: Quick Start on a Multipoint System
3 Quick Start on a Multipoint System
3.1 0) Set Operation Mode
Program one of the units to be a multipoint Master (Operation Mode 2)
Program the Multipoint Slaves (Operation Mode 3)
3.2 1) Set Baud Rate
Set the Baud Rate to match the baud rate of the device to which the transceiver will be
connected.
3.3 3) Edit Radio Transmission Characteristics
Set FreqKey, Max Packet Size, Min Packet Size, and RF Data Rate to identical settings on
every radio to be used in the network. It is always a good idea to set the FreqKey, Max
Packet Size, Min Packet Size to values other than the factory defaults.
3.4 4) Edit Multipoint Parameters
Will there be a repeater in the network or do you intend to be able to run diagnostics on the
network? If so set that value to 1.
Set the NetworkID to a value between 1 and 4095, a value of 255 enables the use of the
callbook.
The rest is just fine-tuning.
Revision 1.0c 3 © 2003 Intuicom, Inc.

Section 4: Tuning Transceiver Performance
4 Tuning Transceiver Performance
The Intuicom Communicator II allows you to tune several parameters to optimize its
performance for your particular application. All adjustments are done through the Intuicom
Communicator II setup interface, a user interface that eliminates the need for setup diskettes, DIP
switch settings, or custom software.
The setup program is invoked by connecting the Communicator II to any computer running a
terminal program, setting the baud rate for that terminal program to 19200 baud, and putting the
transceiver into setup mode (on most models this is done by pressing the Setup button). While
any terminal program, which can be set to 19200 baud, will work, examples for this manual were
generated using Symantec ProComm. You may connect to either the Main Data Port or the
Diagnostics port.
Parameter Setting
Baud Rate 19200
Data Bits 8
Parity None
Stop Bits 1
Parity Check None / Off
Carrier Detect None / Off
Flow control None
Table 4-1: Serial Settings to access Setup Menu
When the setup program is invoked all three LEDs on the Communicator II front panel will turn
green and will remain green for the entire time the transceiver is in setup mode. The main menu
screen for the setup program is shown in Figure 4-1:
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Section 4: Tuning Transceiver Performance
Figure 4-1: Setup Main Menu
The initial menu provides the transceiver's unique serial number, firmware version, and the set of
choices for editing the operational parameters and viewing the performance data.
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Section 5: Operation Mode Selections (Main Menu Option 0)
5 Operation Mode Selections (Main Menu Option 0)
When item (0) is selected the Operation Mode Menu appears as shown in Figure 5-1. The
Operation Mode option is used to designate the method in which the particular transceiver will
be used. The Communicator II operates in a Master to Slave configuration; therefore, any
transceivers that are intended to operate together must be set up as such. In a point-to-point
setup, either the master or slave may be used on either end of the communications link without
any performance degradation. One consideration when setting up the transceivers is that a
number of parameters are controlled by the settings in the master; therefore, you may wish to
deploy the master on the communications end where you will have easier access to the
transceiver.
Figure 5-1: Operation Mode Menu
5.1 (0) Point-to-Point Master
As mentioned previously, the Communicator II transceiver operates in a Master/Slave
configuration. When designated as a master in point-to-point mode, the Transceiver will call
any or all slaves it is instructed to call in the Call Book. In Point to Point mode the master
determines the settings used for most of the Radio Transmission Characteristics, regardless
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Section 5: Operation Mode Selections (Main Menu Option 0)
of the settings in the slaves and/or repeaters. The settings for the slave and repeater(s) not
determined by the master are RF Xmit Power, Slave Security, and Retry Time Out.
A quick method of identifying a master is to power up the transceiver. Prior to establishing a
communication link with a slave or repeater all three of the master's LEDs will be solid red.
5.2 (1) Point-to-Point Slave
When set up as a point to point slave a Communicator II transceiver will communicate with
any master in its call book, either directly or through up to four repeaters. When functioning
as a slave, the Entry to Call feature in the transceiver's call book Figure 5-2 is not
operational. The slave will communicate with any master listed in its Call Book that calls it.
5.3 (2) Point-to-Multipoint Master
The Communicator II transceiver may be set to run in Multipoint mode, which allows one
master to simultaneously be in communication with numerous slaves. A Point-to-Multipoint
Master will communicate only with other transceivers designated as Point-to-Multipoint
Slaves or Point-to-Multipoint Repeaters.
Please refer to the next chapter 'Multipoint Operation', for more information on running a
Multipoint network.
5.4 (3) Point-to-Multipoint Slave
Setting (3) allows the transceiver to operate as a slave in a Multipoint network.
Please refer to the next chapter - 'Multipoint Operation' for more information on running a
Multipoint network.
5.5 (4) Point-to-Point Slave/Repeater
Option 4 allows you to designate the transceiver to act as either a slave or a repeater,
depending upon the instructions received from the master for the specific communications
session. When a transceiver is placed in an ideal location, this setting offers the flexibility of
using that transceiver as an end point in the communication link (slave) or to extend the link
to a point further (repeater). These functions are not, however, available simultaneously (the
transceiver cannot act as both a slave and a repeater at the same time). This option is
available in point to multipoint operation.
A word of caution: A transceiver designated as a repeater has no security features, as
explained below. When a transceiver is designated as a Point-to-Point Slave/Repeater, it will
allow any master to use it as a repeater.
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Section 5: Operation Mode Selections (Main Menu Option 0)
5.6 (5) Point-to-Point Repeater
The transceivers allows the use of up to four repeaters in a point to point communications
link, significantly extending the operating range. When designated as a repeater a
Transceiver behaves as a pass-through link. All settings for the call book, baud rate, and
radio transmission characteristics are disabled. A repeater will connect with any master that
calls it (the repeater must still be set up in the master's call book).
The use of one repeater in a communications link will reduce the top data throughput
available when compared to a direct master to slave link (generally on the order of 50%).
This impact is generally noticed only when using the Transceivers at 115.2 KBaud. The
throughput does not decrease further if two or more repeaters are used.
For more information of programming point-to-point links using one or more repeaters
please refer to Entering or Modifying numbers in the Call Book.
5.7 (6) Point-to-Point Slave/Master Switchable
Mode 6 is a versatile option that allows the transceiver to be controlled entirely through
software commands. When in mode 6, a number of key parameters in the transceiver’s user
interface may be changed either directly (as if using the Terminal program) or through the
use of script files. In addition, when the transceiver is in mode 6 and not calling a slave it
will be a slave itself and accept any appropriate calls from other transceivers.
In mode 6:
• This mode only works through the data port with diagnostics turned off.
• The transceiver remains in slave mode until called by another Transceiver in its Call
Book or instructed to call another transceiver through an AT command. The master
will disconnect when DTR goes low.
• The user may change settings in the user interface without using the setup button (this
may be of particular value if the transceiver is not in an easily accessible location).
• Predetermined script files may be used which allow any of the transceiver's settings to
be changed upon execution of that file. This, in turn, allows the user to establish push
button command sets that will instruct the Transceiver to call a predetermined slave.
Note: All AT commands issued to the transceiver in Mode 6 must be in ALL CAPS
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Section 5: Operation Mode Selections (Main Menu Option 0)
Script File
Command Function Controlled
ATXF_ Frequency Key
ATXT_ Max Packet Size
ATXD_ Min Packet Size
ATXX_ Transmit Rate
ATXR_ RF Data Rate
ATXP_ RF Transmit Power
ATDT_ Position in Call Book to Call
ATD_ Allows specific Intuicom Communicator II serial
number to be entered to call
ATXC_ Used in conjunction with the ATD command, instructs
transceivers which repeater path to follow
ATXS Instructs Transceiver to go into Setup Mode
Table 5-1: Mode 6 Commands
Using Mode 6 to call a transceiver not listed in the Call Book:
Mode 6 will accept the command ATD####### where ####### is any arbitrary modem
serial number such as 5551234. Upon receipt of this command the modem will call that
modem even though the number is not in the sending modem’s Call Book.
Using Mode 6 to call a transceiver through one or two repeaters:
In conjunction with the ATD command the transceiver may be instructed to use the
repeater(s) specified in the Call Book. This means it is possible to call an unlimited number
of slaves through script files in mode 6 and have up to 10 different repeater combinations.
To call a transceiver through one or two repeaters:
The repeaters to be used must first be set up in the Call Book. This would be done by setting
up a number to call (this may be a dummy number) through the repeater(s) which you wish
to use. An example of this is shown below as entries 3 (one repeater) and 4 (two repeaters)
in the Call Book.
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Section 5: Operation Mode Selections (Main Menu Option 0)
Figure 5-2: Call Book Menu
Issue the command ATXC# where # corresponds to the position in the Call Book where the
repeater(s) is/are located.
Issue the command ATD####### where ####### is the serial number of the transceiver with
which you are attempting a link. The transceiver will link first to the repeater(s) specified
and then to the slave transceiver.
If you wish to link to a different slave, this time without using a repeater, it is imperative that
you reissue the ATXC# command. Either:
1. Issue the command to a location in the Call Book with no repeaters. In the Call Book
above, for example, this could be ATXC2; or
2. Issue the command ATXCA, where A corresponds to All and no repeaters will be
used.
The Slave security may be disabled so that a modem operating as a slave (Modes 1,4, and 6)
will connect to any modem calling it regardless of whether the calling modem is in the
slave’s Call Book. This feature is necessary when there are more than 10 transceivers which
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Section 5: Operation Mode Selections (Main Menu Option 0)
may call into a slave and will allow any of the units in the system to call in. For more
information please see Slave Security in Section x-x.
5.8 (7) Point-to-Multipoint Repeater
Setting (7) allows the transceiver to operate as a repeater in a Multipoint network.
Please refer to the next chapter, 'Multipoint Operation', for more information on running a
Multipoint network.
5.9 TDMA (If TDMA firmware option installed)
Please contact Intuicom for more information about the TDMA operation mode firmware
option.
5.10 (F) Ethernet options
This menu is only needed for Ethernet modems. Although this menu is included here, it has
nothing to do with the Modem Mode (for example, if the modem mode is "0", entering "F"
doesn't change the Modem Mode to "F"). Please see the Ethernet addendum for more
information on this menu.
Revision 1.0c 11 © 2003 Intuicom, Inc.

Section 6: Multipoint Operation
6 Multipoint Operation
6.1 Theory of Operation
In a Multipoint system a transceiver designated as a master is able to simultaneously be in
communication with numerous slaves. In its simplest form, a Multipoint network functions
with the master broadcasting its messages to all slaves and slaves responding to the master
when given data by the device connected to the RS232 port.
It is important to note the differences between point-to-point and multipoint systems. In a
point-to-point system all packets are acknowledged, whether sent from the master to the
slave or from the slave to the master. In a multipoint system outbound packets (those sent
from the master or repeater out to slaves or other repeaters) are sent a fixed number of times
(see Master Packet Repeat). The receiving transceiver (slave or repeater) will accept the first
packet received that passes the 32 bit CRC, however the packet is not acknowledged. On the
return trip (data going back to the master) all packets sent are acknowledged or retransmitted
until they are acknowledged. Therefore, the return link in a multipoint system is generally
very robust.
Traditionally, a Multipoint network is used in applications where data is collected from many
instruments and reported back to one central site. As such, the architecture of such a system
is completely different from point-to-point applications. The theoretical maximum number
of slaves that can be configured into a Multipoint network is a function of the data
throughput needed from each of the slaves. For example, if the network will be polling
slaves once a day to retrieve sparse data, several hundred slaves could be configured to a
single master. If, on the other hand, each slave will be transmitting data at greater levels then
fewer slaves may be connected to the master (the overall system will be closer to capacity
with fewer slaves). The theoretical limit of a Multipoint system is influenced by the
following parameters:
1. Size of the blocks of data. The longer the data blocks the smaller the system capacity.
2. RS232 baud rate.
3. The amount of contention between slaves.
4. Use of repeaters. A single repeater in a Multipoint network will decrease overall
system capacity by 50%; more than one repeater does not further decrease network
capacity.
6.2 Installing Multipoint Systems
When installing multipoint systems it is important that some planning is done up front.
Unlike point-to-point systems (where the master will set certain system parameters), a
multipoint system requires that many parameters be set consistently on all transceivers in the
system. This includes RF data rate, min and max packet size, number of repeaters, and
frequency key.
Revision 1.0c 12 © 2003 Intuicom, Inc.