Rosslare AC-825IP - AC-825 IP Input and Output Connections; Understanding AC-825 IP Input Types

Input and Output Connections
AC-825IP Hardware Installation and User Guide 31
4. Input and Output Connections
This chapter describes the AC-825IP access control panel's input and output
connections.
4.1 Input Types
There are four input types:
 Normally Closed (N.C.)
 Normally Open (N.O.)
 Single EOL resistor
 Double EOL resistor
Supervised inputs have three states:
 Normal
 Abnormal
 Trouble
The Trouble state is caused by either tampering with the input circuit or by a
faulty hardware installation. Once an input is configured as a supervised input,
add a resistor of 2.2 kΩ, 8.2 kΩ, or both on the input circuit. See the following
diagrams.
4.1.1 Normally Open Input Connection
A Normally Open Input has 2 states:
 Switch Open – Normal State:
Loop resistance = Infinite (open circuit)
 Switch Closed – Abnormal State:
Loop resistance = 0 (short circuit)
Figure 23: Normally Open Input Connection
4.1.2 Normally Closed Input Connection
A Normally Closed Input has two states:
 Switch Closed – Normal State:
Loop resistance = 0 (short circuit)
 Switch Open – Abnormal State:
Loop resistance = Infinite (open circuit)