PLC Turned OFF, variable still to 1

Hi everyone!

I have an object on WINCC Unified V17 which turns into green when a bit in a word (PLC Variable) turns to 1, and when is 0 turno into grey.

When the PLC turns off, the bit remains 1 and I cannot turn hte object into grey color.

Is there any chance to check when the PLC is off and to write 0 to my bit?

Thnak you in advance!

Hi Tcastagna,

the value of a tag (connected to a PLC tag) will only change if the value is changed in PLC. If the connection is lost, the value would not change.

But the "QualityCode" property will change. You can use this in a script to change the style.

Kind regards
Stefan

You can also set 0 as substitute value for that HMI tag when communication fails: