Installation guide

LMU Users Guide
V1.0.6 December 10 2009
Copyright ©CalAmp DataCom Inc 2009
- 16 - CalAmp Proprietary & Confidential
4.3
4.3.1 Relay Outputs
Output Types
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 shows a typical relay connection to one of
the LMU’s outputs.
Vehicle Power
(+12VDC)
Relay
Coil
Relay
Contacts
Relay
Ground
LMU
85
86 87
30
Output 0
Figure 3 - Sample Relay Output Wiring
4.3.1.1 LMU-1000™ vehicle disable feature
To use the LMU-1000™’s vehicle disable feature, the ignition wire on the vehicle going
between the starter relay and the ignition key switch should be cut. The two cut ends should
be connected to the LMU-1000™ Relay Contact wires (blue/pin 2 and green pin 3). It
doesn’t matter which of the two cuts ends connects to which Relay Contact wire.