Rosslare AC-225E - Normally Closed Supervised Single Resistor Input Connection; Figure 13: Normally Open Supervised Input (Double Resistor); Figure 14: Normally Closed Supervised Input (Single Resistor)

Input and Output Connections
AC-225x Series Hardware Installation Manual 23
Figure 13: Normally Open Supervised Input (Double Resistor)
4.1.5 Normally Closed Supervised Single Resistor Input Connection
Connect a 2.2 kΩ resistor in series to the input switch contacts.
Normally Closed Supervised Input has 3 states:
 Switch Closed – Normal State:
Loop resistance = 2.2 kΩ
 Switch Open – Abnormal State:
Loop resistance = Infinite (open circuit)
 Short circuit across input terminals – Trouble State:
Loop resistance = 0 (short circuit)
Figure 14: Normally Closed Supervised Input (Single Resistor)