Tag Error: Uncertain_InitialValue

I’ve faced this error on OPCUA tags.
I’ve disabled and then enable the OPC device connection on the gateway.
After that the error is gone.
But want to know the reason behind this error “Uncertain_InitialValue”.
Does anyone knows why this kind of error occurs?

Aman Pawar

It’s not necessarily an error, it’s the initial state/value for an OPC tag. It might mean that the OPC UA server simply hasn’t sent you a tag value yet.

But the tags were showing that state for more than 24 hours.
I want to know the cause.

Can you make the connection to that server without security and get a Wireshark capture to troubleshoot?

No, is there any other way?

It’s a lot messier and you’ll probably need to work with support, but something like:

Delete or disable all tags you’ve currently created from this server. Search for these loggers and set them to TRACE level: OpcUaSubscriptionModel, OpcUaSubscriptionSynchronizer, DataValueConsumer. (see docs for changing log levels)

Subscribe to a single tag. It might be easier to just use Quick Client in the gateway. Make a note of the NodeId / OPC Item Path, we’ll need to know what it is.

After ~30 seconds have elapsed and the quality is still Uncertain_InitialValue get the logs and upload them here or give them to the support agent.

This will allow us to see if the item is being successfully created and then whether or not the server is sending a value. The problem is these loggers will be very noisy.

What server is it you’re connected to?