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IF2 Network Reader User Guide 57
Isolated Input Interface
Open Collector 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 ground-
ing practices for both the IF2 and the input device.
In this situation, the IF2 provides power to the pull-up resistor for the open collec-
tor. Connect the +Input pin to the +12 VDC source as shown in the next illustration.
Open Collector Input Interface
Use the Output Interfaces
Each IF2 output interface is optically isolated from the IF2, polarized, and rated for
5 to 48 VDC at 0.25 A. All IF2 outputs include internal thermal fuses that trip if the
load exceeds 0.25 A, and the fuses are self-recovering once the excessive load is
removed. The high and low contacts are exposed and isolated from ground. Tran-
sient suppression limits output voltage spikes to 65 VDC.
GPIO Output Specifications
+
-
External
input
switch
10-48 VDC
Twisted
pair
-Input
+Input
+Input
+12 V
Ground
- Input
Signal Description Min. Typical Max.
Leakage current (High) Switch output, high leakage current 0 mA 1 mA 10 mA
V
sat
(Low) Switch output on, saturation voltage
with 0.25A load 0V 1V 1.5V