Send momentarily value from WinCC to Step7

[PeterJ]

Hi

Is there a way to send a ex. '1' from a WinCC button to the PLC just momentarily for an edge detection?

I need it for an alarm reset logic, that do not start the machine up again after reset of the fault.

Thank you in advance

 

[rQx]

You could just send set the value 1 to an integer and then in the PLC reset it as you like, thus making it momentary.

 

[mk42]

The standard way I've seen to do momentary push buttons on an HMI is to set a bit when the button is pushed, and then reset it when the button is released. The value is true while the operator presses the button, and is changed to false when it is no longer pressed. If you need to send an integer instead of a bit, same concept applies: Press change value to 1, release change value to 0.

If you need it to be truly momentary edge detection, true for only one cycle, then rQx's solution seems like the best solution. Have the HMI send a value, and then let the PLC do it's edge detection and reset the value from the code.