Isolated Input Interface; Open Collector Input Interface - Intermec IF2 User Manual

Chapter 5 — Using the IF2 GPIO Interfaces

Isolated Input Interface

Open Collector Input Interface

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+12V
+Input
- Input
Ground
IF2 Powered Input
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 IF2. 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 IF2 and the input device.
In this situation, the IF2 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.
External
input
switch
External
input
switch
-
+
10-48 VDC
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