Moore Industries WLM User manual

WLM
Wireless Link Module
April 2016
288-787-01 B
WLM
Wireless Link Module Ethernet 2.4-2.4835GHz
Ethernet
2.4-2.4835GHz

2 The Interface Solution Experts
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Table of Contents Page
Introduction ......................................................................................................................................... 4
Quick Start ......................................................................................................................................... 5
Modem Configuration ......................................................................................................................... 6
Main Menu Option (0): Set Operation Mode........................................................................................8
Main Menu Option (1): Set Baud Rate .............................................................................................. 10
Main Menu Option (2): Edit Call Book ............................................................................................... 10
Main Menu Option (3): Edit Radio Transmission Characteristics ..................................................... 12
Main Menu Option (4): Show Rado Statistics ................................................................................... 16
Main Menu Option (5): Edit Multi-Point Parameters .......................................................................... 18
Main Menu Option (8): Password ..................................................................................................... 21
Modem Location ............................................................................................................................... 22
Using an External Antenna ............................................................................................................... 22
Modem Front Panel LED’s ............................................................................................................... 23
Sample Data Communication Links.................................................................................................24
Technical Specifications ................................................................................................................... 26
Troubleshooting ................................................................................................................................ 26
Appendix A ........................................................................................................................................ 28

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Introduction
TheWLMtransceivermodem isa highperformance, wirelessradio modemdesigned forheavy-duty industrialdata
communicationsin the2.4 to 2.4835GHz license-free band.It employsadvanced spreadspectrum frequency
hoppingand errordetection technologyto achieve very reliable, noise and interference immune operation.AhighRF
datarateof 188kbps and superior sensitivity provideultra reliable dataintegrity.The WLMhas a ratedrange of up to
10 miles (15 km) in optimal conditions with line-of-sight and an omni directional antenna. This can also be extended
furtherwithrepeaters orhigher gainantenna.
TheWLM can be operated ina number ofdifferent modes to satisfy abroad range ofcommunications requirements.
Itcan be configured for point-to-pointor multi-point operationwith an unlimitednumber of remote sites ona single
masterdepending on datathroughput requirements. Repeaters can be used in the system to extendrange and
eliminate dead RF zones that are blocked by obstructions.
An external antenna can be used with up to two hundred feet of coax. Consult the factory if cable lengths longer
thantwo hundredfeet are required. Thisprovides a boost in signalstrength and decreases induced noiselevels.
With an external antenna, radio modems can be located inside buildings or metallic enclosures.
TheWLM will operatein virtuallyany environmentwhere Ethernetcommunications are required.The transceiver’s
Ethernet port is a standard 10Base-T connector with either a straight through or crossed selection.
TheUser Guide covers the operatingmodes and configurationsthat are availableto users of the WLM.It also
providesthe userwith technicalinformation and specifications.
In most applications, the WLM comes pre-configured for the application in which it is going to be used. In most
casesno other configuration is required.If you are unsure ifthe modem needs further configuration,please contact
MooreIndustries-International,Inc.

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Quick Start
The WLM comes pre-configured for your application (unless otherwise requested). In most cases, configuration
settings are not required.
Although each modem is tested before shipment, it is recommended that a bench test be done before the modem is
installed in its application.
In all applications, there is a master modem and one or more remotes. Some applications may also have one or
more repeaters. This “Quick Start” will assume that there is a repeater in the system. If there is not, ignore the parts
that talk about repeaters, as the remote modems should operate the same with or without repeaters.
Locate the modem labeled “Master” and connect its power supply to an appropriate 120VAC power source, then
connect it to the modem. The “P” LED should come on and stay on
Note: on all modems, the “C” LED will come on for the first few seconds after power up.
Next, locate the modem(s) labeled “Repeater” and connect to power. The LED’s “P” and “C” should come on and
stay on. Now locate the modem(s) labeled “Remote” and connect to power. The LED’s “P” and “C” should come on
and stay on. The modems are now ready to carry Ethernet data.
Connect the “Master” and “Remote” (or “Repeater/Remote” if your network has one) to the Ethernet equipment that
has been pre-tested for operation.
Note: The WLM will not support “Peer to Peer” communications. The equipment that is attached to the
WLM must be capable of operating in a “Master (host) to Remote” network.
It is recommended that a “Ping” test be done at this point. This can be done in either direction, but remember that
only a “Master to Remote” or “Remote to Master” connection can be established through the modems. Also note
that because of the MAC filtering done by the modems, if you take a piece of Ethernet equipment on one side of the
WLM network and move it to the other side of said network, you must power down both the “Master” and the effected
“Remote” in order to re-establish connectivity through the modems. If powering down the modem is not practical to
the application, the modems will rebuild the MAC filter table in approximately six minutes and communications
should return. Once a successful “Ping” test has been done, the modems are ready for communication. If the “Ping”
test was not successful, please refer to the trouble shooting section of this manual or contact Moore Industries-
International, Inc. tech support for assistance.

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Configuration
In most cases, the WLM comes pre-configured from the factory. However, it may sometimes be necessary to
change the configuration. Most parameters are changed in the radio section of the modem although there are a few
settings that are set using switches. If you are not sure if you need to change the configuration of the WLM, you
probably don’t. Please contact Moore Industries-International, Inc. for further information if you are unsure about your
configuration.
Switch Settings
Access to the switches is via removal of the left side (LAN side) end plate.
Note: Leave switch positions 4, 5 and 6 at factory setting of off unless otherwise directed by Moore
Industries-International, Inc. Changing these switches requires a radio parameters change.
Mac Filtering Function
All devices capable of generating Ethernet traffic have a MAC (Medium Access Control) address. This address is
used in the communications of Ethernet data.
The WLM is factory set to perform MAC level filtering. This means that it learns all the MAC addresses from the LAN
it is connected to, and only forwards data packets across the radio links which are destined for addresses located
across the radio link.
The MAC address table can store up to 10,000 addresses. Each entry to the table has a lifetime of six minutes after
which the address is deleted. This dynamic table building allows for the possibility of stations being removed from
the LAN. The net result of this filtering functionality is the reduction of unnecessary network traffic across the radio
link.
Any device that does not communicate on the network within a six minute time out period will be dropped from the
radio’s MAC table list. If frequent changes in the LAN cabling are done, cycle the DC power or press the reset button
on the front of the modem.
Note: Many Ethernet networks have data packets that are not covered by the MAC filter function (broadcast
packets for example). These packets can occupy tremendous amount of the network’s bandwidth and
overwhelm the WLM section of the network. If the WLM’s are going to be installed where they are linked to
an open network (on office network, etc…), a properly configured router or switch should be installed to
protect the modems from excessive data traffic. If you are unsure about your network, please consult with
your network administrator.

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Radio Parameter Configuration
The WLM allows you to set several parameters to suit your particular application. All adjustments are done through
the WLM setup program, a user interface that eliminates the need for setup diskettes or custom software.
To access the configuration menu, connect the radio modem’s configuration port to any terminal program with port
settings of 19.2Kbaud, 8 data bits, no parity and one stop bit. With the modem connected to the PC running the
terminal program, press the Configure button. While any terminal program will work, examples for this manual were
generated using the Microsoft Windows 2000 application “HyperTerminal.”
Note: When using HyperTerminal, set Handshaking to none and use a standard straight through cable. If
you are using something other than Hyper Terminal, it may be necessary to use a cable that has pins 4 and
6 connected together on the modem side of the cable. Contact Moore Industries-International, Inc. for further
information.
Table 1: Terminal Settings
When the setup program is invoked the RF “IN” LED on the WLM front panel will flash once when the Configure
button is pressed and the RF “Link” LED will remain on for the entire time the radio modem is in setup mode.
The main menu provides the radio modem’s unique call book number and the set of choices for editing the
operational parameters and viewing the performance data.
Figure 1: Main Menu
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lortnoCwolFenoN

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Main Menu Option (0): Set Operation Mode
When item (0) is selected, the Operation Mode Menu appears as shown in figure 2. The Operation Mode option is
used to designate the method in which the particular WLM will be used. The WLM operates in a master to remote
configuration; therefore, any radio modems that are intended to operate together must be set up as such. In a point-
to-point setup, either the master or remote may be used on either end of the communications link. One
consideration when setting up the radio modems 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 radio modem.
Figure 2: Mode Menu
Shown below are example settings. Please refer to supplied configuration sheets for your modem’s configuration.
(0) Point-to-point Master
The WLM operates in a master/remote configuration. When designated as a master in point-to-point mode, the
radio modem will call any or all remotes it is instructed to call in the call book. The master determines the
settings used for all Radio Transmission Characteristics (except power), regardless of the settings in the
remotes and/or repeaters.
(1) Point-to-Point Remote
When set up as a point-to-point remote, an WLM will communicate with any master in its call book, either
directly or through one or two repeaters. When functioning as a remote, the Entry to Call feature in the radio
modem’s call book (Figure 3) is not operational. The remote will communicate with any master on the list that
calls.
(2) Point-to-Multi-Point Master
The WLM may be set to run in multi-point mode, which allows one master to simultaneously be in
communication with numerous remotes. A point-to-multi-point master will communicate only with other radio
modems designated as point-to-multi-point remotes or point-to-multi-point repeaters.
(3) Point-to-Multi-Point Remote
Setting (3) allows the radio modem to operate as a remote in a multi-point network.
Please refer to the section entitled multi-point operation, for more information on running a multi-point network.

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(4) Point-to-Point Remote/Repeater
Option 4 allows you to designate the radio modem to act as either a remote or a repeater, depending upon the
instructions received from the master for the specific communications session. When a radio modem is placed
in an ideal location, this setting offers the flexibility of using that radio modem as an end point in the
communications link (remote) or to extend the link to a further point (repeater). These functions are not, however,
available simultaneously (the radio modem cannot act as both a remote and a repeater at the same time).
Note: Configured as a repeater, a radio modem has no security features as explained below. When a radio
modem is designated as a Point-to-Point Remote/Repeater, it will allow any master to use it as a repeater.
(5) Point-to-Point Repeater
WLM radio modems allow the use of up to two repeaters in a communications link, significantly extending the
operating range. When designated as a repeater, a radio modem behaves as a pass-through link. All settings for
the call book, baud rates, 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 remote link (generally on the order of 50%). The throughput does not decrease further if two
repeaters are used.
(6) Point-to-Point Remote/Master Switchable
Mode 6 is not applicable to the WLM radio modems.
(7) Point-to-Multi-Point Repeater
Setting (7) allows the radio modem to operate as a repeater in a multi-point network.
Please refer to the section entitled, multi-point operation, for more information on running a multi-point network.
(F) Ethernet options
This selection is factory set and should not be changed.

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Main Menu Option (1): Set Baud Rate
The baud rate setting affects the interface between the radio and Ethernet sections of the modem. All of the settings
are factory set and should not be changed.
Main Menu Option (2): Edit Call Book
The Call Book is an innovative feature in the WLM that offers both security and flexibility in use. The Call Book
accomplishes this by allowing the user to determine with which other WLMs a given radio modem will communicate,
based on the call book numbers for both the master and remote. The radio modem’s call book number is encoded in
the microprocessor and identified on a label on the modem. The instructions provided in this section are for point-to-
point mode only. Use of the Call Book for multi-point systems is explained later in this chapter. For two WLM radio
modems to communicate in point-to-point mode, three events must occur:
1. The call book number for the master must be listed in the remote’s Call Book.
2. The call book number for the remote must be listed in the master’s Call Book.
3. The master must be programmed to call the remote.
As shown in figure 3, the Call Book allows users to set up a list of up to 10 WLMs to communicate with, designate
up to 2 repeaters to be used in communicating with a given radio modem, and tell the master which remote to call.
To direct the master to call a remote, the Remote must be in the Call Book Menu. A specific remote may be called
by entering (C) at the prompt, followed by the menu number corresponding to that remote. To call any available
remote in the list, the user should enter C and then A (for All).
Note: To call a remote through one or two repeaters, you must call that remote directly (as opposed to
using the Call All option). When Call All is selected, the master is not able to connect with any remotes
through repeaters. This is because the master calls every remote in the list when instructed to call all and
will connect with the first remote to respond. When calling through a repeater, the master must first call that
repeater and establish a communications link with it prior to making contact with the remote.
Figure 3: Call Book Menu

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Entering or modifying call book numbers in the Call Book is a straightforward process. When in the Call Book menu
select the entry number (0 – 9) you wish to edit. You will be prompted for the new number (formatting is automatic,
you do not need to enter the dash). Once the number is entered (unless it is 000-0000) you will be asked for the call
number of the first repeater to be used. If no repeater is to be used, enter the escape key; your entry will be
complete and you will be back in the Call Book menu screen. If you enter a repeater number you will then be
prompted for the call number of the second repeater to use. If a second repeater is being used, enter the call number
at this time; if not then enter the escape key. Once again, the radio modem will retain your entries, as shown in the
updated Call Book menu screen.
Note: It is important that the Call Book slots (0 – 9) are filled sequentially beginning with 0, the first slot in
the book. Call book numbers do not need to be entered in numerical order; however, there must not be any
000-0000 numbers in the middle of the list of good call book numbers. The reason for this is that when a
master is instructed to Call All available remotes, it will call all remotes listed until it reaches the first
number of 000-0000. If a valid call book number is entered after the all zero number, it will not be recognized
as a valid number to be called by the master.
Edit Call Book in Multi-Point Systems
In a multi-point system the remotes and repeaters are not listed in the master’s Call Book. When establishing such
a system, it is necessary only to have the master’s call book number in each remote’s and repeater’s Call Book,
and to have each repeater’s call book number in the Call Book of each remote which may potentially communicate
through it.
The following example shows the Call Books of a multi-point system comprised of a master, repeater and remote in
which the remote can communicate either through the repeater or directly to the master:
Multi-Point Master Call Book (Unit Call book number 555-0001)
No call book number entries are necessary in the master’s Call Book
The Master’s Call Book may be programmed to call any entry
Multi-Point Repeater Call Book (Unit Call book number 555-0002)
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Multi-Point Remote Call Book (Unit Call book number 555-0003)
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)1(2000-555
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Main Menu Option (3): Edit Radio Transmission Characteristics
When option (3) is selected in the main menu, the screen in figure 4 appears, which allows the user to modify the
radio transmission characteristics of the radio modems. As stated in the warning, these parameters are for the
experienced user who has a good understanding of the principles of radio data transmission. They should be
changed only after consulting this manual.
It is important to note that the radio parameters between any radio modems in communication will be determined by
the settings for the master (except when in multi-point mode, see (4) RF Data Rate and (5) RF Power below). While
the settings may be modified for the remote(s) and/or repeaters, they will be overridden by the master’s parameters.
Note: For most Ethernet applications, these settings are already optimized. Please consult with Moore
Industries-International, Inc. before making changes.
Figure 4: Radio Parameters Menu
Shown below are example settings. Please refer to supplied configuration sheets for your modem’s configuration.
(0) FreqKey
Selection (0) in the Radio Parameters menu allows the user to modify the hopping patterns of the radio modems
to minimize the interference with other WLM radio modems in operation in the area. For instance, if there
were 10 pairs of WLMs in operation within a factory or refinery, changing the Frequency Key would ensure
that they would not jump onto the same frequencies at the same time for the same length of time.
There are 15 choices available for the Frequency Key (0-9 and A-E). It is recommended that a list be maintained
of the settings for each master to ensure that each is set to a different hopping pattern.
(1) Max Packet Size and (2) Min Packet SizeSelections
(1) and (2) allow the user to designate the size of the packets (in bytes) used by the radio modem in its
communications link. This may be of particular value when using the WLM with different
communications software packages; you may find that throughput is optimized when packet sizes are
restricted by the radio modem.
Packet size is determined by a combination of the settings entered by the user and the RF Data Rate. In
addition, the Max Packet Size is a function of the setting selected for the Min Packet Size. Tables 2, 3 and 4
provide the packet sizes for each different combination of settings.

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Table 2: Minimum Packet Size Settings (bytes)
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06108
112121
262261
323302
473442
524582
684623
735763
885804
946944
Table 3: Maximum Packet Size Settings where RF Data Rate=3
0 1 2 3 4 5 6 7 8 9
084204652788401021631251
1218244066729801421041651
2612384460869211821441061
30263258648001611231841461
44204652788401021631251861
58244066729801421041651271
62384460869211821441061671
763258648001611231841461081
804652788401041631251861481
944066729801421041651271881
Maximum Setting
Minimum Setting

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0 1 2 3 4 5 6 7 8 9
051638597001121341461581602
102243648501721841961091212
262748609111231351571691712
313254759611731951081102222
4638597001121341461581602822
5243648501721841961091212332
6748609111231351571691712832
7254759611731951081102222442
88597001121341461581602822942
9364859721841961091212332452
Table 4: Maximum Packet Size Settings where RF Data Rate=2
Minimum Setting
Maximum Setting
(3) Xmit Rate
There are two settings for the Transmit Rate parameter. For normal operation, the WLM should be set at
Transmit Rate 1. Transmit Rate 0 is useful to qualitatively gauge signal strength. When set to Transmit Rate 0
the radio modems will transmit data back and forth continuously, and the strength of the signal may be gauged
by viewing the Show Radio Statistics option.
Due to the fact that the radio modems transmit continuously when Transmit Rate is set to 0 (whether or not they
have data to send) they use radio frequency spectrum unnecessarily. Therefore, Transmit Rate 0 should be used
only as a diagnostic tool and not for normal operation.
(4) RF Data Rate
The WLM has two settings for the RF Data Rate (the speed that the modems talk to each other). Setting 2
should be used when the radio modems are close together and data throughput is to be optimized. Setting 3
should be used when the radio modems are farther away and a solid data link is preferred over data throughput.
Note: The RF Data Rate setting must be identical for all units in the system. Any radio modem with a
different RF Data Rate than the master will not establish a communication link.
(5) RF Xmit Power
The WLM offers users the ability to modify the Transmission Power of the radio modem. There are 10
power settings available (1-10) which are roughly linear. Therefore a setting of 10 is full power (or 500 mW) and 1
is 10% power (or 50 mW). The following guidelines should be followed when setting the RF Transmission Power:

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Table 5: Power Transmit Settings
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(6) Remote Security
With option 6 the user may disable the radio modem’s security so it will accept a call from any other WLM.
The default setting is 0 where security is enforced (the caller’s call book number must be in the remote’s Call
Book). With a setting of 1 security is disabled.
(7) RTS to CTS
This setting is not applicable to the WLM and should not be changed from the factory setting (the factory
setting is 0)
(8) Retry Time Out
The Retry Time Out parameter allows the use to determine when a remote will drop a connection to a master or
repeater in multi-point mode. The default setting is 255, meaning that if one packet in 255 from the master is
sent successfully to the remote it will maintain a link. The lowest setting is 8, at which a remote will drop
connection much faster.
The Retry Time Out parameter is useful when a multi-point system is used with a moving master or remotes. As
the link gets weaker, a lower setting will allow a remote to drop it’s link and search for a stronger connection.
While intended primarily for multi-point systems, the Retry Time Out parameter may also be modified in point-to-
point systems. In point-to-point mode the Retry Time Out should not be set to a value of less than 151.
(9) Lowpower Mode
The Lowpower Mode is not applicable to the WLM. This setting should not be changed.
(A) High Noise
Use the menu to indicate if the modem will be operated in an environment with a high degree of radio noise and
interference. With a setting of 1, the rejection of interference is improved, at the cost of reduced range and/or
throughput.
(B) MCU speed
This setting is factory set to 1 (high speed) and should not be changed.

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Main Menu Option (4): Show Radio Statistics
Option (4) in the main menu allows the user to view data transmission statistics which have been gathered by the
Transceiver during the most recent session. Statistics are gathered during each data link and are reset when the
next link begins. Ideally, noise levels should be below 30, and the difference between the average signal level and
average noise level should be 30 or more. High noise levels tend to indicate other sources of RF interference, while
low signal levels indicate a weak link. The “Local” stats are the statistics that are being gathered by the modem you
are connected too while “Remote1, Remote2, and Remote3” are the stats of the repeater(s) that the modem you are
attached to is using to get back to the master modem. The following sections provide information useful to the
process of troubleshooting and improving radio links.
Average Noise Level
The average noise level indicates the level of background noise and interference at this modem and at each of the
modems used as repeaters in the link. The number is an average of the noise levels measured at each frequency in
the modems’ frequency hop table. The individual measurement values at each frequency hop channel are shown in
the frequency table. The frequency table is accessed by pressing the ENTER key on the computer when the radio
statistics menu is displayed. Average noise levels will typically fall in the range of 15 to 30. Average noise levels
significantly higher than this are an indication of a high level of interference that may degrade the performance of the
link. High noise levels can often be improved with bandpass filters, antenna placement or antenna polarization.
Please contact Moore Industries-International, Inc. for more information.
Average Signal Level
The average signal level indicates the level of received signal at this modem and at each of the modems used as
repeaters in the link. For each of these, the signal source is the modem that transmits to it. The number is an
average of the received signal levels measured at each frequency in the modem’s frequency hop table. The individual
measurement values at each frequency hop channel are shown in the frequency table. The frequency table is
accessed by pressing the ENTER key on the computer when the radio statistics menu is displayed.
For a reliable link, the average signal level should be at least 30 higher than the average noise level reading. The
table below provides an approximate conversion of average signal level values into the more common dBm (decibel
milliwatts). Low Average Signal Levels can often be corrected with higher gain antennas, antenna placement, and
use of repeaters. Contact Moore Industries-International, Inc. for more information.
Overall Rcv Rate (%)
The Overall Rcv Rate measures the percentage of data packets that were successfully transmitted from the master
to the slave on the first attempt without requiring retransmission. A number of 75 or higher indicates a robust link that
will provide very good performance even at high data transmission rates. A number of 25 or lower indicates a weak or
marginal link that will provide lower data throughput. An Overall Rcv Rate of 100% will provide approximately 90
Kbaud of bandwidth with an RF data rate of 3 (Radio Transmission Parameters Menu) and approximately 110 Kbaud
of bandwidth with an RF Data Rate of 2. These numbers are reduced approximately 50% if there are one or more
repeaters in the network.
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Numberof Disconnects
If, during the course of performing a link test, the link between the master and the slave is broken, and the radios
lose carrier detect, the occurrence is recorded in the Number of Disconnects value. The value indicates the total
number of disconnects that have occurred from the time the link test started until the radio was put into config mode.
Under normal operating conditions, the number of disconnects should be 0. One or more disconnects may indicate a
very weak link, the presence of severe interference problems or loss of DC power to the Master or Repeater if one is
present.
Note: A remote and/or repeater will record a disconnect if the system master is placed into configuration
mode or has power interrupted while the remote and/or repeater is linked to the master
Radio Temperature
The radio temperature value is the current operating temperature of the radio in degrees C (Celsius.) For proper
operation, WLM radio modems must be in the range of –400 to 750 C.
Multi-Point Operation
In a multi-point system, a radio modem designated as a master is able to simultaneously be in communication with
numerous remotes. In its simplest form, a multi-point network functions with the master broadcasting its messages
to all remotes and the remotes responding to the master as appropriate.
Traditionally, a multi-point 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 remotes that can be configured into a multi-point network is
a function of the data throughput needed from each of the remotes. For example, if the network will be polling
remotes once a day to retrieve sparse data, several hundred remotes could be configured to a single master. If, on
the other hand, each remote will be transmitting data at greater levels then fewer remotes may be connected to the
master (the overall system will be closer to capacity with fewer remotes).
The theoretical limit of a multi-point system is influenced by the following parameters:
•Size of the blocks of data—the longer the data blocks the greater the system capacity
•Throughput
•The amount of contention between remotes
•Use of repeaters—a single repeater in a multi-point network will decrease overall system capacity by 50%; more
than one repeater does not further decrease network capacity

18 The Interface Solution Experts
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Main Menu Option (5): Edit Multi-Point Parameters
Figure 5: Multi-Point Parameters
Shown below are example settings. Please refer to supplied configuration sheets for your modem’s configuration.
In a multi-point network, it is critical to know how many radio modems are being used as repeaters. Any radio
modem that is used as a repeater essentially becomes a master to the remotes and other repeaters to which it is
communicating. Therefore, the user must first identify how many repeaters are connected to the master by assigning
a value in parameter (0) Number Repeaters. This parameter must also be set for each repeater in the system (i.e.,
in the event that a repeater is connected to one or more other repeaters). This parameter does need to be set for
multi-point remotes.
In point-to-point operation, the WLM radio modems acknowledge every data packet transmitted. In a multi-point
network, the remotes do not acknowledge transmissions from a master to the remotes. This is to prevent system
overload. If the remotes acknowledged all data transmissions from the master in a large multi-point system, then all
system capacity would be spent having the master listen for acknowledgments from the remotes. Because the
transmission is not acknowledged by the remotes, 100% confidence does not exist that every remote has received
every message from the master. To address this issue, the user may modify option (1) Master Packet Repeat,
assigning a value between 0 (the packet is transmitted once) to 9 (the packet is repeated 9 times). For networks
with solid RF links, this parameter would be set at the lower end of the scale (0-1). If the network has some weak or
marginal links, it would be set toward the higher values. If a remote receives a packet from a master more than once,
it will discard the repeated packets received.
While packets transmitted from the master to the remotes in a multi-point network are not acknowledged, packets
transmitted from remotes to the master are. However, it is possible that more than one remote will attempt to
transmit to the master at the same time, and it is therefore important that a protocol exists to resolve contention for
the master between remotes.
This is addressed through parameters (2) Max Remote Retry and (3) Retry Odds. The Max Remote Retry setting
defines how many times (0 to 9) the remote will attempt to retransmit a packet to the master before beginning to use
a back-off algorithm. Once the remote has unsuccessfully attempted to transmit the packet the number of times
specified in Max Remote Retry, it will attempt to transmit to the master on a random basis.

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The Retry Odds parameter determines the probability that the remote will attempt to retransmit the packet to the
master; a low setting will assign low odds to the remote attempting to transmit and conversely a high setting will
assign high odds. An example of how this parameter might be used would be when considering two different remotes
in a multi-point network, one close in with a strong RF link and the other far from the master with a weak link. It may
be desirable to assign a higher Retry Odd to the remote with the weaker link to give it a better chance of competing
with the closer remote for the master’s attention.
Another parameter in a multi-point network is (4) DTR Connect. This setting is not applicable in the WLM’s and
should not be changed from a factory default of 0.
The repeater’s hopping pattern must also be set in a multi-point network; this is accomplished with parameter (5)
Repeater Frequency. Setting this parameter is in contrast with point-to-point mode where the repeater
automatically uses the master’s hopping pattern. The repeater may be programmed to either use the master’s
hopping pattern selection (0) or its own selection (1).
Option (6) NetWork ID allows multi-point networks to be established without the use of the Call Book. If the
NetWork ID is set to any value lower than the default (255) the remotes in the multi-point network will communicate
with the first multi-point master or repeater heard with the same NetWork ID. When the NetWork ID is used multi-
point masters and repeaters may be replaced without reprogramming all of the remotes in the network. In addition,
this allows a remote to establish communications with different masters (though not at the same time) without
having the call book numbers in the Call Book. This is very useful in mobile multi-point applications. (8) Multi Master
Synch is reserved for multi-point applications with concentrations of master units where it is necessary to reduce
interference between the masters. Please contact the factory for more information on the use of this feature.
(9) 1PPS Enable/Delay
This setting is not applicable to the WLM and should not be changed from the factory default of 255.
(A) Remote/Repeater
The Remote/Repeater mode allows a WLM in a multi-point system to simultaneously act as a remote and a
repeater. When in this mode a WLM will repeat any packets sent from a master as well as send them out the
Ethernet port. This gives a WLM set as a repeater to act as a remote at the same time. 0 disables this mode, 1
enables it. For this feature to work, the modem must be configured as a point-to-multipoint repeater.
(B)Diagnostics
The WLM has the ability to run a diagnostic program while in normal operations. Contact the factory for
additional information.
(C) SubNet ID
The default setting is “Disabled.” Please see the SubNet ID section of this manual.
(D) Radio ID
Used with the Diagnostics. Contact the factory for additional information.

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SubNet ID
The WLM series modems offer a SubNet ID system for use in multi-point networks using Network ID. This feature
allows the users to dictate what path a given repeater or remote will use to achieve a link to the network master. For
example, if a remote modem in a given network has line of sight to the network master and one or more repeaters,
but only one repeater is close to that remote, SubNet ID can be used to link that master with the proper repeater
only.
Note: This feature can only be used in networks using Network ID with one or more repeaters.
There are two components to SubNet ID. The first is the Xmit (transmit) SubNet ID, and the second is Rcv (receive)
SubNet ID. The Xmit SubNet ID is used only by repeaters and is the ID that a repeater sends out when sending data
to other repeaters or remotes. The Rcv SubNet ID is the ID that repeaters or remotes look for to receive data.
Note: The master is not affected by these settings. Only repeaters and remotes use these settings.
Remotes only use Rcv SubNet ID.
Modem configurations are as follows (see diagram 1 below):
Master No setting used
Repeaters Any repeater that should be linked directly to the master should have the Rcv SubNet ID set to
0. Any repeater using another repeater as its link, needs the Rcv SubNet ID set to the Xmit
SubNet ID of that repeater. The Xmit SubNet ID can be set to anything from 1 to E.
Remotes Any remote that should be linked directly to the master should have the Rcv SubNet ID set to 0.
Any remote using a repeater as its link should have the Rcv SubNet ID set to the Xmit SubNet
ID of that repeater.
Diagram 1
Rcv not set
Xmit not set
Remote 4
Rcv = 0
Xmit = 1
Repeater 1
Rcv = 1
Xmit = 2
Repeater 2
Rcv = 0
Xmit not set
Remote 1
Rcv = 1
Xmit not set
Remote 2
Rcv = 2
Xmit not set
Remote 3
Rec/Xmit
not set
Master