Matrox Iris GT MIL, Installation And Technical Reference, Page: 111 / 256

Connecting external devices to auxiliary output signals 111
Connecting to a PNP-compatible PLC device
To connect your Matrox Iris GT to a PNP-compatible PLC device, you must first
connect an external pull-up resistor between them. The external pull-up resistor
is needed because PNP-compatible PLC devices expect to be connected to a device
that can provide power (a sourcing device) and your Matrox Iris GT is a sinking
device. Therefore, connect an output signal of your Matrox Iris GT and the
sourcing input to an external pull-up resistor. In addition, connect the ground of
the PNP-compatible PLC device and the ground of your Matrox Iris GT to a
common ground.
The external pull-up resistor assures that when the output is disabled (off ), the
external resistor will pull-up the PLC input to a positive voltage (+V). This creates
an inversion, with the PLC input "on" when your Matrox Iris GT output is "off",
and vice-versa.
+V
In 0
GND
PNP-
compatible
PLC device
GND
External
pull-up
resistor
Power
source
Matrox Iris GT digital I/O
and power connector
+24V
max.
AUX(USER)_OPENC_OUT0
1
1
Note that the output can
sink up to 100 mA.