Installation guide
LMU-4200™ Hardware and Installation Guide  
V1.0.9    November 13, 2010 
Copyright ©CalAmp DataCom Inc 2010
  - 23 -  CalAmp Proprietary & Confidential 
2.4.2  3-Axis Accelerometer Input 
The LMU-4200™ supports an internal 3 Axis Precision Accelerometer as one of its discreet 
inputs. When the LMU is moved in any direction, the associated input will be in the High 
state. If the LMU’s accelerometer does not detect motion, then the input will be in the Low 
state. No external connections are required for this functionality to be operational. 
2.4.3  Outputs 
The LMU’s and ioPOD;s outputs are designed to drive external relays. These outputs 
provide a high-current, open-collector driver that can sink up to 150 mA each. These drivers 
may be used to drive external relays that can then control vehicle functions such as door 
locks, fuel shut-off valves, sirens and lights. If additional current is required to drive the 
relays, external circuitry can be added to source the current. This diagram is a typical use of 
an output to drive a relay. 
Vehicle Power 
(+12VDC)
Relay 
Coil
Relay 
Contacts
Relay 
Ground
LMU
85
86 87
30
Output 0
Figure 12 - Sample Relay Wiring 










