At our plant we've set up a PI server, which retrieves data from an interface server. At this interface server, we have several interfaces gathering data from two units.
Both units have the same interfaces running:
1. OPC-DA 1 interface for important data (about 30 tags) (for these tags we also have an OPC-HDA interface for history retrieval when the interface fails)
2. OPC-DA 2 interface for less important data (about 800 tags)
3. OPC-HDA interface for the rest of the data (about 2-3000 tags)
4. OPC-HDA interface which only runs when OPC-DA 1 has failed and history retrieval is necessary
We are in the middle of transferring tags from OPC-HDA (number 3) top OPC-DA (number 2).
But at the moment we're having an issue on OPC-DA (number 1) of unit 1.
All tags work correct, except for 1 digital tag, which at random times gives the status 'Comm fail'. Due to that 'Comm fail'. A short time later it is ok again. An example is seen in the table below:
|Number of Values:||24|
|03-Apr-18 02:19:37||Comm Fail|
All other tags on the same interface are working correctly. The same interface on the other unit is working correctly. And this problem started randomly, as far as I can recall, no changes to the PI server or interfaces were done at the time.
Anyone familiar with this issue?