Develop a PLC program that will control a miniature set of traffic lights. These lights will go through a normal sequence, but will have pedestrian cross walk buttons that will activate a cross walk signal when pressed. When done the student should understand the design and implementation of time dependent control circuits.
We want to develop a controller for a set of traffic lights that is at the cross of Main St. and a less used Cross Rd. The lights under two possible sequences as shown below. In the normal sequence the green for cross is shorter with no cross walk light. If a cross walk button is pushed while the Main light is green or yellow the Cross green light will be on longer with a walk sign.
1. The instructor will describe how to connect the PLC, power supply, buttons, etc at the beginning of the laboratory period. As a group you will connect the circuits. Components used will include push buttons and red/yellow/green output lights.