User`s guide

Installing the Input Expander 5
Installation
outputs. This is really handy for testing out multiple units, and since the card
can be used with so many Alcorn McBride Inc products, it’s a cheap investment
for speedy debugging!
Powering the Module
The Input Expander can be powered from the unit’s
power supply or from an external power supply up to
24VDC, depending on how much distance you want to
have between the contact closures and the unit. The
location of the Input Expander in between the switches
and your unit doesn’t matter. There are two jumper
clips at the top right of the board as shown to the right.
Also note the diagram on the circuit board in addition to
the directions below.
Power from the Unit
Default from the factory, the two jumper clips should be placed on pins 1 & 2 of
JP3 and JP4. This setting is good for a distance of 6ft or less from the unit.
Above 3ft of cable, we recommend shielded wiring. There is a 6ft shielded
cable available for purchase along with this unit. Please see our spec sheet for
the Input Expander for more details. NOTE: The DVM2 family of products
does not have the ability to power the Input Expander. You will need an
external power supply to power the Input Expander when using it with a
DVM2.
Field Power/External Power
To have up to 1000ft between the unit and the switches, you can use an external
power supply to provide the DC voltage you need. The maximum voltage
input on all of our units at this time is 24VDC. We have an AC/DC “wall-wart”
supply available purchase along with this unit, but you are not required to use it.
Please see our spec sheet for the Input Expander for more details.
Make sure your DC
supply is not plugged in.
Simply clip off the
connector from the end
of your DC supply
(typically a barrel jack)
and split the cables long
enough to strip the tips
and connect them as
shown to the appropriate terminals. Plug in your DC supply and use a
voltmeter to verify which wire is the positive DC node and which is ground.
Unplug the DC supply. Connect the ground wire to FIELDGND and the