Installation guide

LMU Users Guide

V1.0.6 December 10 2009

- 88 - CalAmp Proprietary & Confidential

11.2

There are two formal types of request messages than can be sent to an LMU and one

informal type. The formal types, which are Unit Requests and Parameter Requests messages,

generally elicit an SMS response from the LMU. The informal type, AT Commands, does

not. The formatting and use of each is detailed in the following sections.

SMS Request Messages

11.2.1 Unit Request Messages

The Unit Request messages are designed to produce specific responses or actions from an

LMU. They are of the format “!R<#>” where <#> is a number from 0 – 9. The available

Unit Request messages are as follows.

Request a Text Status Message:

!R0<Rdddddddddd>

This SMS message will force the LMU to return a Text Status message to the originating

mobile. If the Rdddddddddd string is included, the Text Status message is redirected to the

phone number indicated by dddddddddd.

Parameter Write Request

!R1 <parameter write string>

This request allows the equivalent of an AT$APP PARAM command to be initiated

remotely via SMS. The <parameter write string> should match the format of the AT$APP

PARAM command. That is, it should contain a CSV string containing the Parameter ID, the

Parameter Index and one or more values depending on the Parameter ID. No response is

sent back to the originating mobile.

Request a Real-Time PEG Action

!R3,<Action Code>,<Action Modifier>

This SMS message will force the LMU to perform the Action indicated by the <Action

Code> and <Action Modifier> fields. For a list of all available Actions please refer to the

PEG Programming Guide.

Request an SMS Event Report

!R4

This request will force the LMU to send an SMS Event Report to the originating mobile.

Request a GPS Status Report

!R5

!RG

!Rg

This request will force the LMU to send an SMS GPS Status Message to the originating

mobile.

Software Update Request

!R8 <new version number> [<URL of server>]