Understanding Supervised vs. Unsupervised Input Devices

Door input devices can be supervised or unsupervised

·         Unsupervised input devices have two states: active or inactive.

·         Supervised input devices have four states: active, inactive, short, and open.

Unsupervised inputs have limited functionality. If a wire is cut or shorted between the input module and a normally open device. The server cannot determine the change and the device would remains in inactive state even when the switch is closed.

To make the input device supervised, use two 1K resistors in the circuit (as shown in the diagram below).

·         In the inactive state, the circuit measures 2000 ohms.

·         In the active state, the circuit measures 1000 ohms.

·         In the short state the circuit measures 0 ohms

·         In the open state the circuit measures infinite ohms.

When the input device is supervised, ICPAM can determine if a wire is cut or shorted.

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See also:

Device Configuration Properties

Understanding Normally Open vs. Normally Closed Devices

Device Configuration Properties Summary