PanelView Plus 6 1000 on the case sealer, application came out of View Studio ME v8 or v9, it's been on the wall since before my time. Controller's a CompactLogix 1769-L33ER. The alarm list on the terminal stamps events 11 minutes earlier than the same event in the PLC fault log, and the gap keeps growing. QA picked it up because the terminal alarm and the SCADA alarm for the same jam are 11 minutes apart on paper.
I set the terminal clock by hand from Terminal Settings, Time/Date back in January and it's drifted out again since, so I power cycled it twice on the off chance. No change, not that I expected one. One of the lads reckoned battery, but it doesn't lose the time on a power cycle, it just drifts.
Is there anything in an application that old that'll pull the time off the L33ER, or am I setting that clock by hand forever?
We had a Plus 6 lose time and that one was the battery, but it went back to 2007 on every power cycle, it didn't drift. Yours keeps time through a power cycle, so I think you can leave the battery alone.
Does the terminal show a battery warning on the Terminal Settings screen at all? Photo of ours attached, the warning sits at the bottom.