Installation guide

LMU Users Guide

V1.0.6 December 10 2009

- 11 - CalAmp Proprietary & Confidential

4.1

Working with Inputs, Outputs and

Power

The CalAmp LMU products offer a variety of inputs and outputs to enable a wide variety of

vehicle and asset tracking applications. For a complete description of what types of inputs

and outputs are supported by a given device, please refer to its installation guide.

I/O Introduction

4.2

The LMU products offer the following input types. Please note that not all inputs are

supported by all products.

Input Types

4.2.1 Digital Inputs

Digital inputs are meant to detect on/off behaviors such as ignition on/off or door

opened/closed.

The LMU’s digital inputs are protected from typical vehicle transients and can be directly

connected to most vehicle level logical inputs from 6 volts up to vehicle power. Their input

impedance is approximately 10 kΩ.

The Ignition input is pulled to ground through a 10kΩ resistance, where the other inputs can

be configured to be biased high or low. For those biased high, the input is pulled to the

supply voltage through a 10 kΩ resistor. For those biased low, they are pulled to ground

through a 10 kΩ resistor. The diagrams below show some typical connections to the inputs

in both a high- and low-biased configuration: