1 To understand and be capable of utilizing programmable logic controller to perform control system
2 To understand the working principle of traffic light control system
Experiments Observations:
On the first sequence, cars from East and West can cross the junction. At the same time, pedestrians at North and South are allowed to cross the road. After 8 seconds, pedestrians need to stop crossing the road. East and West turn to yellow light.
After 3 seconds, East and West turn to red light but cars from East can turn to South and cars from West can turn to North. After another 5 seconds, they need to stop turning.
After 2 seconds, the second sequence starts. Cars from North and South can cross the junction. At the same time, East and West pedestrians can cross the road. After 8 seconds, pedestrians need to stop crossing. Immediately, North and South turn to yellow light.
After 3 seconds, they need to stop but cars from North can turn to West and cars from South can turn to East. After 5 seconds, they need to stop turning.
If S2 switch is turned ON, the sequences repeat again to continue allowing and disallowing cars and pedestrians crossing the junction and road. If S2 is turned OFF, the process ends with all red lights ON.
If S3 is turned ON, pedestrian sequences will be OFF, which means only car crossing sequences can be observed.
