Installation guide

LMU Users Guide

V1.0.6 December 10 2009

- 47 - CalAmp Proprietary & Confidential

Comm. refers to any features of the LMU that have something to do with the behavior of its

wireless modem. This section is intended to cover the Comm related features not discussed

in the Activating the CalAmp LMU sections found in the LMU Installation Guides.

Working with Comm

7.1

The Comm profile is the set of parameters the LMU needs to access the wireless network. A

profile consists of four values, the Packet Dial-String (Parameter 2316), the network

username (Parameter 2314), the network password (Parameter 2315) and the modem driver

to use (S-120 or S-150). The first Comm. profile is defined when you activate the LMU. That

is, the LMU will use the default Packet Dial String and the supplied username and password.

These initial values are stored in index 0 of the Dial-String, username and password

Parameters. When using Comm Index 0, the LMU will make use the modem driver defined

in S-Register 120.

Using a second Comm profile

The second Comm. profile is stored in index 1 of the Dial-String, username and password

Parameters and makes use of S-Register 150 for the modem driver. The LMU can be

commanded to use this second profile in one of two ways, either controlled via PEG, or

controlled by changing the Packet Dial-String-Current Index Parameter (Parameter 2317).

For instance, say you have tethered an Iridium data modem to your LMU which is to be

used when the internal modem does not have coverage. For this example, the Iridium device

uses a Dial-Up Networking phone number of 6195551000. The following commands would

set-up the second Comm Profile for use with the Iridium device.:

ATS150=144

AT$APP PARAM 2316,1,6195551000

AT$APP PARAM 2314,1,”dummy”

AT$APP PARAM 2315,1,”dummy”

AT$APP PARAM 2317,0,1

7.2

In the same lines as using a second Comm profile, the LMU can use a second GPRS

Context setting. The LMU has the added ability to automatically switch which Context it

uses. This switching will occur after a certain number of failures when attempting to dial the

GPRS network.

GPRS context switching

The GPRS Context values are stored in parameter 2306. Keep in mind that the format of the

Context string changes depending which device you are using. For the LMU-4100 the

Context command would look like:

AT$APP PARAM 2306,0,”IP:myapn.myoperator.com”

For the LMU-1000 it would look like:

AT$APP PARAM 2306,0,”myapn.myoperator.com”