OpenPDC / OpenHistorian : Using adder or multiplier for measurements : on both or only OpenPDC?

GPA Products openHistorian
1

Hello !
In OpenPDC I applied a correction of ‘-120’ to certain phase angles. After initialing the PDC and its equivalent in OpenHistorian (STTP connection between the two); I note that this modifier is not automatically included / replicated in the measures of OpenHistorian. Should I report the same change in OpenHistorian to keep consistency; or is the fact of applying it once in OpenPDC enough to correct the signal on the whole downstream chain? I do not want to have a (-120) + (-120) = (-240) correction on my OpenHistorian data … As it’s phase angle ; it is difficult to compare directly OpenPDC/OpenHistorian values at a specific time using the Monitoring > Graph Measurement tool because values are changing quick …

I think I have to do it on OpenPDC only ; but I prefer to have your confirmation !

Regards,

Thank you very much for your answer

2

The adjustment, i.e., the Adder of -120 in your case, is not automatically reflected in the metadata between systems, this is intentional. The “value” is adjusted at measurement publication and the subscriber receives the adjusted value up arrival at the receiving system. If it were included in the metadata on the subscriber, the value would be adjusted by -120 again.

3

Thank you very much for your answer.

Effectively positioning this correction on the first PDC of the chain allows the value to be modified throughout the downstream chain.

Topic closed

Regards