MNL000443.doc
Revision 00
09/19/2016
© Versum Materials, Inc. as of the revision and date shown. All rights reserved.
Confidential and Proprietary Data
Page
-
10
4.4.1 Supervised Inputs
The system supports two supervised inputs from the customer interface. Supervised
inputs are digital inputs, which are monitored via a window comparator. These inputs
are monitored for normal operation, alarm type, and fault conditions.
A normally open switch is to be used as an input device. This switch must have a 750
ohm resistor in parallel with the contacts. When the switch contacts are open the
circuit will provide a signal, which represents a normal operating condition. When the
switch contacts are closed, the circuit will provide a signal which indicates an alarm
condition. An open wire in this circuit, or a short circuit, will produce an out of range
signal, which indicates a circuit fault.
Switch contacts must be rated for 20ma @ 24VDC.