Last published value is "null, Uncertain_InitialValue..." in the tag Editor

Ignition Designer:


Ignition gateway:


The ignition gateway can read the data from the opc server , but tag browser show null value in the first picture?

Presumably this means KSE hasn't sent a PublishResponse containing values for those tags yet for some reason. In the QC you're just doing a read, not a subscribe, so it's different.

It doesn't look like anything is wrong with your Ignition configuration, so it might be a Kepware issue. If you can turn off security for the connection and get a Wireshark capture we can verify that the Subscription and Monitored Items get created but no values are received.


The IP address of the opc server is 192.168.150.23 and the ignition gateway is 192.168.150.4

A screenshot is not sufficient. Please post the actual PCAP file, or send it to IA support.

We'll need the PCAP file.

Make sure you start the capture and then edit/save the connection once you are recording so that the Subscription and Monitored Item creation is captured.

pacp.rar (2.4 MB)

The file size is too big, so I had compress it. 7Z or WinRAR can uncompress it.

This capture only contains traffic for an existing connection, not a new one that includes subscription and item creation by edit/saving in Ignition.

It doesn't contain any PublishResponses with data change notifications, but that doesn't mean anything because they aren't immediately following the subscription and items being created.

there was a login error : IllegalArgumentException: Cannot create PyString with non-byte value

It is not work after restart the vision module in gateway