Upgraded CompacLogix firmware, lost some tags

[MartyMaucher]

CompactLogix L33ER with Panel View 7 system originally running v28 was working fine in the field. Updated the PLC software and firmware to v30 to fix one of the signals in ladder logic. Now some of the tags are showing "?".

Would updating the firmware and software to v30 change the location of tags if the set of tags did not change?

 

[PLC Pie Guy]

What was there before????
Date and Time I assume??

 

[MartyMaucher]

Yes, time and day of the week. Those seem to be the only tags affected. I guess that is a clue.

 

[jstolaruk]

Look for a GSV command in the PLC logic that is reading the PLC clock and verify that it and any other logic associated with it is working correctly. Then check the HMI tags.