Isolated Input Interface; Open Collector Input Interface - Intermec IF5 User Manual

Chapter 5 — Using the IF5 GPIO Interfaces

Isolated Input Interface

Open Collector Input Interface

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Use this method to minimize noise induced by distance or
grounding characteristics. The isolated input avoids induced
noise by referencing a remote input to chassis return of the IF5.
The next illustration shows how this method is wired.
+Input
-Input
Twisted
pair
Isolated Input Interface
The input can be connected to an open collector interface of an
external device. This typically implies that the grounds are tied
together for the two systems. The common ground can be a
source of input noise, so you should follow good grounding
practices for both the IF5 and the input device.
In this situation, the IF5 provides power to the pull-up resistor
for the open collector. Connect the +Input pin to the +12 VDC
source as shown in the next illustration.
+12V
+Input
- Input
Ground
Open Collector Input Interface
External
input
switch
-
+
10-48 VDC
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