Haltech I/O Expander 12 (HT059900) - Manual (Page 5)

Digital Pulsed Outputs ( DPO )
The Haltech I/O Expander 12 features 4 Digital Pulsed Outputs. Each output has
been grouped with a +12V DC Source within the harness, this allows the user to fit
an external relay to control high current devices.
Digital Pulsed outputs are capable of outputting pulsed waveforms with varying duty
and frequency. DPO's can be used to control various devices such as thermo fans,
shift lights, bypass air control valves, boost control solenoids etc.
When a Digital Pulsed output is activated by the ECU the output will switch to ground.
Solenoid valves and shift lights etc can be run directly from the output. However
high current devices such as thermo fans and additional fuel pumps must be
activated through a relay. This way the DPO is only switching a relay and not a high
current draw device.
Digital Pulsed Outputs are limited to 1A Max current draw.
Figure 6 - Digital Pulsed Outputs
Figure 7 - Digital Pulsed Output Relay Wiring
Wiring Harness (optional)
The Haltech I/O Expander 12 can be supplied with a 24 pin wiring harness,
Connections are outlined in detail below:
Main Inputs
There are four main inputs to the Haltech I/O Expander 12
+12V DC Switched (Pink)
Connect this wire to a +12V DC Switched ignition source
+12V DC Battery (Red)
Connect this wire to a constant +12V DC battery supply
Signal Ground (Black / White)
Connect this wire to the signal ground on the ECU
Ground (Black)
Connect this wire to a chassis ground point on the vehicle
Figure 1- Main inputs
WARNING!
Please make sure you configure your I/O Expander 12 with your ECU using
ECU Manager Software before you plug in the wiring harness, as outputs may
turn on undesirably when power is applied if not configured.