Learn three typical examples of PLCs

First, control output program

Equivalent control output

The output depends only on the current state of the control input.

2. Long-term control output

The control output is not completely dependent on the current state of the input, but also on the history of the input. The input has a long-lasting effect on the output.

3. Short-term control output

Its control output is also not completely dependent on the current state of the input. Its input has only a short-term effect on the output, so it is called short-acting output.

Second, single button start and stop procedures

1. One button to start and stop the program instantly

a) OMRON PLC; b) Mitsubishi PLC;

c, d) Siemens PLC;

e) Hollysys PLC; f) AB PLC

The program shown below also has the same function. Only the contacts used here are the first and last strings. The pulse signal is generated using a differential instruction.

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2. Single button short press, long press (more than 1s) stop the program

The above-mentioned one-button start, hold, and stop ladder program is a start, stop, and easy to "confuse." In fact, you can use the button to press a different time to distinguish whether to start or stop.