Installation guide

LMU Users Guide

V1.0.6 December 10 2009

- 9 - CalAmp Proprietary & Confidential

The LMU does support several other AT Commands beyond the Parameter commands. The

most common ones are mentioned through-out this document.

A terminal program such as HyperTerminal is generally used to issue AT Commands to the

LMU. Please refer to Appendix D for instructions on establishing a connection.

3.1.2.2 Parameter Messages

Parameter Messages are a means of remotely changing the parameter values of an LMU

remotely. They can be sent in one of two ways, either via SMS or via an LM Direct™

Parameter message.

SMS Parameter Messages are discussed in detail later in this document. LM Direct™

Parameter Messages are discussed in the LM Direct Reference Guide.

3.2

3.2.1 What are S-Registers?

S-Registers

S-Registers are a standard means of configuring and programming Hayes compatible

modems. Any modem, or modem like device typically supports some range of S-Registers.

The LMU does not support any of the more standard lower S-Registers (such as S-Register

0, which is typically used as the number of rings to wait before answering an incoming call).

The LMU’s S-Registers begin at S120.

S-Registers are accessed through Parameter ID 1024. S-Registers, however, differ from other

Parameters in two ways: first, their Values tend not to change once the LMU is fully

configured. For instance, S-Register 120 is used to select what type of wireless modem the

LMU is using. The other difference is they have an alternate AT Command that can be used

to set and query their values. The commands are:

Set:

ATS<n>=<value>

Query:

ATS<n>?

Query Response:

<value>

S-Registers programmed via this command cannot be masked. To do masking, the

Parameter command described above must be used. Masking is described below.

There are currently 51 S-Registers and can range in value from 0 – 255. The available S-

Registers and their settings are listed in Appendix B.