LMU-2x20™ Hardware and Installation Guide
V1.0.10
December 12, 2010
Copyright ©Calamp Wireless Networks Inc 2010
- 45 -
CalAmp Proprietary & Confidential
4.4.2
3-Axis Accelerometer Input
The LMU-2x30™ 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.
4.4.3
Outputs
The LMU’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 22 - Sample Relay Wiring