User`s manual

Chapter 5 — Using the IF2 GPIO Interfaces
IF2 Network Reader User’s Manual 77
Open Collector Input Interface
Using 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. Transient
suppression limits output voltage spikes to 65 VDC.
Because the outputs are optically isolated, each one can be configured
to switch the high side or the low side of the load. You can power the
load directly from the IF2 or from an external power supply.
In a typical application, the outputs control indicator lamps that
signal good reads or errors. The basic methods for connecting
external devices to the GPIO outputs include:
• Switching the high side, with the load powered by the IF2
• Switching the low side, with the load powered by the IF2
• Switching the high side, with the load powered externally
• Driving a DC relay that controls an AC load
+Input
+12 V
Ground
- Input
GPIO Output Specifications
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