Direct Contacts   

A Direct Contact is a normally open (NO) contact condition. You can link it to any of the following bit operands:

• Memory Bit

• System Bit

• Network System Bit

• Network System Input

• Output

• Timer

A door buzzer is an example of a Direct Contact. When you push the buzzer, power flows through the circuit and the buzzer sounds. When you release the buzzer, the sound stops.

During the system scan, the processor evaluates the program elements net by net.

If the Direct Contact bit operand (the door buzzer) is OFF (logic 0): power will not flow through the Direct Contact. The door buzzer is silent.

If the Direct Contact address (the door buzzer) is ON (logic 1): power will flow through the Direct Contact. The door buzzer sounds.