Design ladder logic for 4 way-traffic light control system
The traffic light is one of the classic examples in PLC ladder logic.
We can take four directions (North, South, west, and east) with three output lamps (Green, Red, and Yellow).
You can build your own concept for making logic for this example.
Follow below tabular column – Logic for the four way traffic light
List of Inputs and Outputs
Traffic Light Control using PLC
Latching rung to operate the system through Master Start and Stop PB.
Starting the timer to turn on output East Green, North-South-West is in red. Parallel circuits are added to turn ON/OFF the output in up next sequence.
Turning on North Yellow and East Yellow. Parallel circuits are added to turn ON/OFF the output in up next sequence.
Turn on East Red and North Green.
Network 5, 6, and 7
Same procedures followed to turn on further outputs.( Refer Tabular column for sequence of operation)
Timer 7 (T7) done bit is used to restart the cycle from beginning
Program runs continuously until STOP PB is pressed
Time delay of 5s has given using timers which will make each cycle with 5s delay.
Training Course: Siemens PLC Training