ELEC 209 PLC Exam

7 ASSIGNMENT 4: TRAFFIC LIGHTS Design a program to run the traffic lights to the following criteria: The RED light is to be ON for 8 seconds The GREEN light is to be ON for 8 seconds The YELLOW light is to be ON for 4 seconds The DON’T WALK light is to be ON when the RED light is ON The WALK light is to be ON when the GREEN light is ON When the Green light has been on for 4 seconds, the WALK light is to turn OFF, and the DON’T WALK light is to flash at 0.5 seconds ON and 0.5 seconds OFF. When the YELLOW light has been ON for 2 seconds the DON’T WALK light is to stop flashing and remain ON ASSIGNMENT 5: COUNTERS Design a program that will use a timer to operate a count up instruction. A START/STOP rung will control the timer TIMER_1 that cycles every 2.5 seconds. A N.O. GREEN_PB pushbutton (must be wired) will control the starting. Every time the timer TIMER_1 is done, the counter COUNTER_1 will increment by one. When the timer TIMER_1 completes 3 cycles, the COUNTER_1 will stop counting up. After the COUNTER_1 stops counting, another START/STOP rung will control the timer TIMER_2 that cycles every 2 seconds. A N.C. RED_PB pushbutton (must be wired) will control the starting. Every time the timer TIMER_2 is done, the same counter COUNTER_1 will decrement by one. When the timer TIMER_2 completes 3 cycles, the COUNTER_1 will stop counting down. Use maintained RESET button to reset the counter to zero any time