Tags and or logic sticking true

I have been experiencing momentary push button tags and/or the logic sticking.
Example: start/stop buttons. We can click the start button, the equipment will start and the start indicator will be displayed. When we click the stop button, the indicator will go out if we click and hold the stop button, but will become true again after we release the mouse button. The equipment will continue to run.
Current work around is by double or triple clicking the “stuck” button to clear the logic or tag, then we can stop the machine by the stop button.

This isn’t happening every day, can be different screens and isn’t the same button or display every time. It can go weeks or a few days and one or more buttons or indicating displays will get stuck.

I first took notice with 7.7 installed on an AB control logix v17
We have since upgraded to 7.8 and a newer AB processor with V20.55 and the issue has followed.


Best practice (IMO) is to not use momentary buttons, regardless of HMI type/brand/model.

I would use a button to set a bit only, with the PLC resetting the bit after doing whatever action is necessary.

I have seen this happen even on “bulletproof” AB Panelviews (both original and PV+) that have the extra overhead comms to handle issues like this.

It’s a bit of a shift in thinking, but it’s a robust solution, regardless of what HMI platform you’re using.

I’ve had that issue too, but thought it was a comms issue with the older PLC5 we were using. It caused some serious problems until it was finally identified.

We resorted to adding in PLC logic to reset the buttons. I would agree with JordanCClark and save yourself some headache by using the PLC to reset the bit.

Thank you Jordan and Kraenbring.
My issue turned out to be an input channel on an analog input card was occasionally shorting out and wreaking havoc.
This issue has since gone away once the input short was dealt with.