TP270 momentary pushbutton

[mikey431 3]

anyody knows how to implement momentary push button on TP 270 HMI ? I created "Button" with "OnButtonUp" Event with "Invert_Bit" but got no luck...

[JesperMP 2]

Hi mike. What is it that you want to achieve ? Buttons on panels dont really have the same functionality as real pushbuttons. Buttons on panels are good for setting or toggling states, not for keeping a state as long as the button is pressed. You COULD have different activities for the events OnButtonDown and OnButtonDown, like set bit and reset bit. But that is not a good practice if you ask me. I always use the set bit function in the HMI, evaluate the bit in the PLC, and finally reset the bit in the PLC.This is as bulletproof as possible.

[mikey431 3]

I am really dummy on Siemens so correct me if i am wrong. i want to create a momentary button on HMI, once it is pressed, it signal to start the logic.Is that possible to reset that same bit in the PLC if you use the set function in the HMI ?

[JesperMP 2]

Yes.

[BITS N BYTES 66]

Jesper's concept is a really bulletproof/good way of implementing control betwen the HMI and PLC. Timing issues of communications between the HMI and PLC are avoided. Follow his suggestion. Have used this method for years.