Installation guide

LMU Users Guide

V1.0.6 December 10 2009

- 115 - CalAmp Proprietary & Confidential

Inputs 1 and 2 are connected to the Load and Unload sensors, which switch between High

and Low signals so while the trailer is connected, the bias isn’t terribly important (i.e. we do

not need to deal with the open circuit case). We do, however, want to make sure the Inputs

false safety violations alerts. For this reason we will want the Inputs to be normally low. That

is, the hatches are closed. This would give:

AT$APP PARAM 1024,38,4,0 (clear bit 2 of S158)

AT$APP PARAM 1024,38,2,0 (clear bit 1 of S158)

Once the Input bias and functions have been changed it is a good idea to reset the LMU to

make sure the changes take effect.

14.2.5 LMU Setup Development – LMU-1000™

14.2.5.1 Setting up the Inbound Address

The Inbound set up of the LMU-1000™ is slightly different from the LMU-4100™. It is

better to just use the Inbound URL and let the DNS look-up manage the Inbound IP

address. It also makes set up a little easier since our configuration commands are sent via

SMS

. Our first SMS setup command is therefore:

!R1 2319,0,”HagenTrucking.HSIInc.com”

14.2.5.2 Setting up the Inputs

The Input setup of the LMU-1000™ is similar to the LMU-4100™. That is, for each Input

we need to select a function (Input or Output) and determine its Bias. On an LMU-1000™,

only Input 2 can be set up as an Input or Output. For this example we want it as an Input.

This gives:

!R1 1024,39,2,0 (i.e. clear bit 1)

For the Bias we will want Inputs 1 and 2 to match the Bias of Inputs 1 and 2 on the LMU-

4100™. This is to prevent any false hatch readings on the LMU-4100™

. This means

clearing bits 1 and 2 of S-Register 158. Since we’re using SMS to program, we will want to

use a single message:

!R1 1024,38,6,0 (i.e. clear bits 1 & 2)

With the Inbound and Inputs configured, this should complete the setup of both types of

LMU.

It would make far more sense, and likely cost less, to use PULS

If we set the bias high, the LMU-4100 would potentially detect a hatch open event every time a trailer

was connected, regardless of actual hatch state.