A control system is needed to control a small shopping center parking lot lighting system and the exterior lighting for the building. The design specifications require that the parking lot lighting and the exterior lighting turn on at dusk automatically. The parking lot lighting should automatically turn off at midnight but the building exterior lighting should remain on until dawn when it is turned off automatically. The system should repeat daily and should not require adjustment for the change in the seasons. Locate and specify an appropriate sensor if it is to operate at 120 vac as an input to a PLC. Create the ladder diagram to accomplish the specified control. Paste the sensor specifications into your document. Solution PLC Logic Programming Counters A counter is a PLC instruction that either increments (counts up) or decrements (counts down) an integer number value when prompted by the transition of a bit from 0 to 1 ( .

1. A control system is needed to control a small shopping center parking lot lighting system and the
exterior lighting for the building. The design specifications require that the parking lot lighting
and the exterior lighting turn on at dusk automatically. The parking lot lighting should
automatically turn off at midnight but the building exterior lighting should remain on until dawn
when it is turned off automatically. The system should repeat daily and should not require
adjustment for the change in the seasons. Locate and specify an appropriate sensor if it is to
operate at 120 vac as an input to a PLC. Create the ladder diagram to accomplish the specified
control. Paste the sensor specifications into your document.
Solution
PLC Logic Programming
Counters
A counter is a PLC instruction that either increments (counts up) or decrements (counts down) an
integer number value when prompted by the transition of a bit from 0 to 1 (