Unjustified transition of tags to Uncertain_InitialValue


Gateway IO-01 has multiple providers that read data from various devices, including Modbus, DNP and several OPC servers such as WAGO OPC Server (PLC) Kep Server and Marcom OPC Server. At some point, the tags are no more visible in IO-01 appears Quality - Uncertain_LastKnownValue.

This happens on different devices, different OPC servers, different connections. The Device connections tab does not show that there are problems with the connection to the devices.

For some reason, even if there is a connection to the devices and OPC, the tags change to Uncertain_LastKnownValue for some time remaining in this state.

Then they are not archived in our SQL database. As a result, gaps are created in the charts for that time when there is an Uncertain state. Until 3 days ago it was working correctly and for some reason now the tags are changing to this state. Are there any comms settings on Gateway that could be causing this?

Where we have a connection to the KepServer also changes the value to Uncertain on IO-01. I created a preview of these values on the OPC KepServer and it seems that there they are read correctly, there are no problems with reading the tags have the Good tag, no breaks in communication.

However, Uncertain tags appear on IO-01, this is also confirmed by QuickClient on the IO-01 server.

As I mentioned this problem did not occur before exists for several days. I also tried to move some of the readings to IO-02 (about 10%) thinking that it is a matter of too many tag or devices on Gateway but the problem continues.

Best Regards,
Michał Góralczyk

You should open a ticket with support.