How can I make it so a digital input sends the program pointer back to the beginning of Main?

Avilarinof

I have code that sort of looks like this:

PROC main()

  !pos 0

  WaitDI diConveyON,0;

  !pos 1

  WaitDI diRunButton,1;

   IF diA=1 THEN
     !do A things
   ELSEIF diB=1 THEN
     !do B things
   ELSEIF diC=1 THEN
     !do C things
   ENDIF
ENDPROC

If diConveyON becomes 1 while the PP is in pos 1, I need to go back to pos 0 and wait until it is 0 again. But if it happens anywhere else, it's irrelevant. What's the simplest and safest way to do that? I thought about using interrupts but surely there must be an easier way?

Thanks in advance.

lemster68

Read up on system inputs in the system parameter manual.  There is a signal exactly for that.  You have to map it and assign the StartMain action.  The program must not be running, or it will be rejected.  Issue Stop system input, the STartMain when program is no longer executing.

graemepaulin

If you move the code into a separate routine then you could use something like:

PROC Main()
           WaitDI di_ConveyOn,0;
           RunProcess;
ENDPROC

PROC RunProcess()

         WaitUntil di_RunButton=1 OR di_ConveyOn=1;

        IF di_ConveyOn=1 THEN

            Return;

        ENDIF

        !the rest of your code

ENDPROC