Installation guide

LMU Users Guide

V1.0.6 December 10 2009

- 27 - CalAmp Proprietary & Confidential

5.1

The Host Port of the LMU-4100™ and LMU-2500™ can be accessed in one of two ways,

either in Host mode, which is meant for use with laptops, and PDAs or MDT mode, which

is meant for use with serial mobile data terminals, bar-code readers, magnetic-card readers

and other ‘dumb’ serial devices. In Host mode, a host device can issue AT Commands,

receive NMEA data or establish a Dial-Up Networking session. In MDT

Using the Host Port

5.1.1 Host Mode - AT Command Setup

mode, the LMU-

4100 will act as a message pass-thru for the dumb serial device. That is, it will send any

messages it receives from the serial device to the backend system and vice-versa.

To issue AT Commands to the LMU-4100™ or LMU-2500™, you would need some

measure of terminal program such as HyperTerminal. Instructions on how to set

HyperTerminal up for use with the LMU™ can be found in the Appendix D of this

document.

The default settings for the Host port are:

• 115200 BAUD

• 8 Data Bits

• No Parity

• 1 Stop Bit

The only setting that can be changed is the BAUD rate. This can be done with one of two

AT Commands:

AT+IPR=<baud rate>

ATS148=<value>

The Host port BAUD rate will change instantly after the AT+IPR command is issued. The

LMU™ must be reset for the BAUD rate to change after using the S148 command. Both

changes are non-volatile and thus the BAUD rate will remain unchanged during subsequent

power cycles. The LMU™ supports the following BAUD rates:

BAUD Rate

S148 Value

4800

9600

19200

38400

57600

115200

Default

255

MDT stands for Mobile Data Terminal. This mode is also known as Generic Serial Device mode or GSD.

The documentation uses both notations.