Wiring the Optoisolated Digital Inputs
To take full advantage of optoisolation, an isolated power supply should be used to provide the voltage at the input
common connection. Connecting the ground of the isolated power to the ground of the controller will bypass
optoisolation and is not recommended if true optoisolation is desired.
If there is not an isolated supply available, the 5 V
DC
, 12 V
DC
, and GND controller references may be used to power
INCOM/LSCOM. The current supplied by the controller references are limited, see +5, ±12V Power Output
Specifications, pg 183 in the Appendices for electrical specifications. Using the controller reference power
completely bypasses optoisolation and is not recommended for most applications.
Banks of inputs can be used as either active high or low. ConnV
s
to INCOM/LSCOM will configure the inputs
for active low as current will flow through the diode when the inputs are pulled to the isolated ground. Connecting
the isolated ground to INCOM/LSCOM will configure the inputs for active high as current will flow through the
diode when the inputs are pulled up to +V
s
.
Figure 3.1 - Figure 3.5 are the optoisolated wiring diagrams for powering INCOM/LSCOM (Bank 0) and
INCOM/LSCOM (Bank 1) and their corresponding inputs.
Chapter 3 Connecting Hardware ▫ 37
DMC-40x0 User Manual
Figure 3.1: Digital Inputs 1-8 (DI[8:1])
Figure 3.2: Digital Inputs 9-16 (DI[16:9])