One of the things that some beginner PLC programmers sometimes struggle with is using open and close contact in the software. In this and next lesson, I’m going to clear this up by using a few simple examples.
Let’s replace the normally open stop switch with a normally closed one and write the program once again.
In previous lessons I wrote a PLC program for running the motor in both momentary and latched modes. In another lesson I wrote a PLC program to run and stop a heavy three phase motor and a fan with a single momentary switch. In the momentary program, there was only one switch that we could use as...
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