Installation Guide

Internal Inputs
Input 8: Motion Sensor (low = no motion, high = motion)
Input 9: VBUS Active
Input 10: Pwr State (low = main power, high = battery power)
Input 11: Vbatt Low
Input 12: Not Used
Input 13: Batt Virt Ign
Input 14: Pure Virt Ign
Input 15: Radio Ring Wake
Input 16: DB Wake
Input 17: Vbus Wake
Input 18: Not Used
Input 19: Crank Detect
Analog to Digital Inputs
A/D 0: External Power Supply Monitor (VIN1)
A/D 1: Ext ADC1 Generic External Analog to Digital Input
A/D 2: Not Used
A/D 3: HW Config
A/D 4: Not Used
A/D 5: Not Used
A/D 6: GPS Antenna Monitor
A/D 7: μP Temperature (internal use only)
A/D 8: Vref
A/D 9: Battery
Outputs:
Output 0: Out-0
Internal Outputs
Output 8: Chrg Disable
3.4.1 3-Axis Accelerometer Input
The HMU-3640™ supports an internal 3 Axis Precision Accelerometer as one of its discreet inputs. When the HMU is moved in
any direction,
the associated input will be in the High state. If the HMU'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.
3.4.2 Ignition and Inputs
The HMU-3640™ provides up to 5 inputs. These inputs are protected from typical vehicle transients and can be directly
connected to most
vehicle level logical inputs from 0 volts up to the vehicle power input level (typically 12 VDC). One of these inputs is dedicated
to sensing the
vehicle’s ignition status to provide for flexible power management. The other 4 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 268k resistance, where the other inputs can be configured to be normally High
(i.e. pulled to
+6v through a 210k resistor) or Low (i.e. pulled to ground through a 43k resistor). The diagrams below show how to connect the
inputs in both a
high- and low-biased configuration:
https://puls.calamp.com/wiki/HMU-3640_Hardware_%26_Installation_Guide 11/27
HMU-3640™ Input Wiring
3.4.3 Outputs
The HMU’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.
Sample Relay Wiring
3.4.4 Serial Streams
https://puls.calamp.com/wiki/HMU-3640_Hardware_%26_Installation_Guide 12/27