From the course: PLC Sequencer Logic

Traffic lights example - Ladder Logic Tutorial

From the course: PLC Sequencer Logic

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Traffic lights example

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- [Instructor] Here's another example where the sequencer is to be used to control traffic in two directions. The first traffic lights control north and south. And the second traffic lights control east and west. Now, the lights on the traffic lights have the following output addresses. For north and south, output two bit zero is for the red light. Output two bit one is for the yellow light. And output two bit two for green light. And for east and west, output two bit three for the red light. Bit four for yellow light. And bit five for a green light. So, the first three bits are for the north and south. And the second set of bits are for the east and west. The operation of the process can be summarized as following. The first step is east and west green light is on, and the north, south red light is on. Then, east and west yellow light is on, while the north and south red light is still on. For the second part, when the east and west is red, then the north and south green light is on. And finally, while still keeping east and west red light is on, the north and south yellow light is on.

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