Analogue trend signals freezes for one minute during the day
Hello,
When we want to see a trend of any analogue signal, we see that during the day the trend shows values that seems to be frozen for about one minute and we don't know the possible cause. The history services are working with no problems and no data gets lost. This problem happens with all the analogue signals of the plant, independent of the controller that is connected.
The system used is System800xA version 6.0.3.3.
Please your advice.
When we want to see a trend of any analogue signal, we see that during the day the trend shows values that seems to be frozen for about one minute and we don't know the possible cause. The history services are working with no problems and no data gets lost. This problem happens with all the analogue signals of the plant, independent of the controller that is connected.
The system used is System800xA version 6.0.3.3.
Please your advice.
Asked 8 months ago
Answers
0
What is your type of historian?
The below is applicable for Basic History:
a) Visit a Log Configuration aspect for an affected object/property.
b) Is Max Time enabled on the primary log?
c) What data status is shown if you retrieve data using the Status tab's Read button (you may have to define a start or end time, the default is to retrieve the 1000 latest samples)?
With Max Time enabled, Basic History will extrapolate the last known value and status in lack of updates from the OPC server. Those samples will have the "Extrapolated" substatus added.
If this is the case, check your OPC server - seems like it hangs up when the trends freeze.
If you have 800xA History or PGIM/S+ History, someone from their support teams should have a look.
Please file a support case to receive further assistance with a suspected OPC server and/or historian.
The below is applicable for Basic History:
a) Visit a Log Configuration aspect for an affected object/property.
b) Is Max Time enabled on the primary log?
c) What data status is shown if you retrieve data using the Status tab's Read button (you may have to define a start or end time, the default is to retrieve the 1000 latest samples)?
With Max Time enabled, Basic History will extrapolate the last known value and status in lack of updates from the OPC server. Those samples will have the "Extrapolated" substatus added.
If this is the case, check your OPC server - seems like it hangs up when the trends freeze.
If you have 800xA History or PGIM/S+ History, someone from their support teams should have a look.
Please file a support case to receive further assistance with a suspected OPC server and/or historian.
0
Hi!
Generally (other historians than ABB), I've seen this when History Server is not time-synchronized with Connectivity/OPC-server nodes.
Check Windows logs for time sync entries.
Check if 800xA time services is ok and you don't have multiple time syncs (from different sources).
Virtualized servers? Even bigger reason to check...
BR
Generally (other historians than ABB), I've seen this when History Server is not time-synchronized with Connectivity/OPC-server nodes.
Check Windows logs for time sync entries.
Check if 800xA time services is ok and you don't have multiple time syncs (from different sources).
Virtualized servers? Even bigger reason to check...
BR
Answered 8 months ago
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