Installation guide
LMU-4200™ Hardware and Installation Guide  
V1.0.9    November 13, 2010 
Copyright ©CalAmp DataCom Inc 2010
  - 21 -  CalAmp Proprietary & Confidential 
2.4.1  Ignition and Inputs 
The LMU-4200™ provides up to 4 inputs on its own and up to 7 with the ioPOD. These 
inputs are protected from typical vehicle transients and can be directly connected to most 
vehicle level logical inputs from 4 volts up to the vehicle power input level (typically 12 
VDC). Their input impedance is approximately 10k. One of these inputs is dedicated to 
sensing the vehicle’s ignition status to provide for flexible power management. The other 
two inputs may be used to sense vehicle inputs such as cooling unit operation, a hidden 
driver “Panic” switch, taxi on-duty/off-duty meter status or many others. 
The ignition input is pulled to ground through the 10k resistance, where the other inputs can 
be configured to be normally High (i.e. pulled to +12v through a 10k resistor) or Low (i.e. 
pulled to ground through a 10k resistor). The diagrams below show how to connect the 
inputs in both a high- and low-biased configuration: 










