NOR Gate Logic in PLC

PLC NOR Gate

• We representing a NOR Logic Gate with two Inputs A and B.

NOR Gate

• NOR Gate provide same result is to put NOT gate on each Input and Follow with AND Gate for resulting inverted inputs.

NOR Gate Truth Table :

Inputs		Output
A	B
0	0	1
0	1	0
1	0	0
1	1	0

PLC NOR Logic :

• Ladder diagram starts with a normally close set of contact Input A and Input B with series with output.
• There is no input provide to Input A and Input B so contacts are closed an output on.
• There is Input provide to Input A and Input B so contacts open an output off.

  

  PLC NOR Gate Logic