Input and Output Requirements
Figure 11: Normally Closed Input Connection
Normally Open Supervised Single Resistor Input Connection:
Connect an 8.2K resistor in parallel to the input switch contacts.
Normally Open Supervised Input has 3 states:
•
Switch Open – Normal State:
Loop resistance = 8.2K
•
Switch Closed – Abnormal State:
Loop resistance = 0 (short circuit)
•
Open circuit across input terminals – Trouble State:
Loop resistance = Infinite (open circuit)
AC-525 Hardware Installation and User Guide
Page 20
