Data missing from Historian archive

Hi all,

We have this device connected to SIEGate. OpenHistorian is subscribed to SIEGate. For weeks now I have been able to view device data using the Trend/Export or the Grafana tool on the OpenHistorian web page.
It has come to my attention that measurement data is not being recorded for 1 of the connected devices. Sure enough the last data you can see recorded historical data is about 4 days ago.
The odd thing is if you go into Real-Time measurements, you can see OpenHistorian receiving the data right now and values are graphing.

Can you guys think of any situation where data is being received and is viewable in Real-Time measurements but no history is recorded/retrievable for it?

Do the timestamps look okay? If a measurement’s timestamp is outside the default tolerance (12 hours) compared to the openHistorian’s local clock, that measurement will not be archived.

EDIT: It looks like the timestamp reasonability check is disabled by default. However, it would still be worth checking the timestamps. If the timestamps coming in are wrong, you may have to query a different time range to see them.

It turns out the PMU was occasionally broadcasting a null date which was getting interpreted as 1/1/1970 which just so happens to be the unix time stamp value of 0. It did save the data in the 1970 folder though.

Hi Jeff - FYI, as Stephen mentioned - you can turn on the timestamp reasonability check to throw out old / badly timestamped data if you like. It is not on by default since many people want to store the data even if the timestamp is bad.