how it possible for data on l3 and data l4 is different for a single tag where other tags on that interface are giving expected results? considering compression & exception settings are the same on both the levels?
L3 meaning Interface Collector and L4 being PI server? Quick check is any out of order data or mismatch in instrument tag i.e. OPC item id for the tag. Request you to quickly check using OPC Client if source data is matching is with destination PI server using insturment tag mapped for that particular PI Point.
Apologies for the confusion here ...L3 and L4 are PI server only, with L3 sending data to L4. The issue being observed is as number of event count for one tag (archive data saved on level 3 )and number of event count (archive data saved on level 4 ) are mismatched .
for Example say 10,15,3,90,100 are values on level 3
and 10 ,15 ,(*) ,90 ,100 are values on level 4 here event entry for 3 is missed on level 4 ,where as it qualifies exception test .
I assume that you are using the PI to PI interface? If so, check out this KB article for best data match considerations.
KB00869 - Considerations for best data match in source and target PI Servers using the PI to PI Interface
Retrieving data ...