OPC-UA Subscription Stops Receiving Value Changes After ~4 Hours

[swes24]

I’m using Node-RED to read 10 variables from an OPC-UA server with the Subscribe method. These variables are subscribed with a 2-second interval and are configured to output on value change. This setup works as expected initially, but after approximately 4 hours, the subscribed variables stop updating upon value change.

Additional Information:

Alarm events are also being monitored in parallel using the AlarmEvents method, and these continue to function correctly even after the 4-hour mark.
Reading variables using Read or Read Multiple methods still works normally without any issues.

Environment:

Node-RED version: 4.0.5
OPC-UA server: Siemens Sinumerik One
node-red-contrib-opcua: 0.2.337

Steps to Reproduce:

Set up OPC-UA Subscribe method in Node-RED for 10 variables with a 2-second interval.
Wait for approximately 4 hours.

Expected Behavior: Subscribed variables should continue to update on value change indefinitely.

Actual Behavior: After ~4 hours, subscribed variables stop updating on value changes.

Questions / Possible Causes:

Is there a known issue with long-running subscriptions in Node-RED OPC-UA?
Are there any recommended configurations to maintain subscription updates over extended periods?

Thank you for any assistance or insights!

[nikso-serg]

A similar problem. I attribute this to problems in the OPC server itself. So far, I have solved the problem by forcibly restarting the OPC client.