How can I arrest the implementation of STEP7 which can be resumed?

boneless said:

Could you elaborate a little bit?

You want to run a function if the button is pushed and quit running it when another is pushed?

If so, you use a SR flipflop with the two buttons.

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Steve Bailey said:

You appear to laboring under a common beginner's misconception. You seem to think that when the machine is doing nothing, the PLC has stopped. That's incorrect. Even when the machine is idle, the PLC is still running its program. It is simply not turning anything on or off.
You'll have to program a Boolean instruction that, when properly included in the logic, will pause a sequence of operations and allow the sequence to resume when given the proper command.

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boneless said:

That was what I was going to say .

You have to remember that the function you are using is/ should be cycling between 0 and 100 ms. So at least 10 times a second.

Your code will be executed this many times. If you have a timer for example, the code will execute, look at the status for the timer and if it is not done yet, it will not execute whatever that timer is controlling.

So you should have:

1. A bit that starts the function
2. In between every step of your program that you want to control, the same bit that will make it jump to the end of that function.
3. A status integer, which will "remember" what particular part of the program you are at.

If you are beginning, it would be smart to put every separate part in its own function(block) and use the integer + the start bool to start every function sequentially.

You CANNOT stop the program from running. Imagine it did, how would you ever evaluate the status of your start or stop button?

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