Large tag subscription fails to update

[Sgilk]

I have a 1000 tag license for the WebIQ runtime on ctrlX OS. I am able to deploy my 1000 tag project to the runtime, but OPC UA subscription updates are only firing for the first 500 tags.

I am subscribing to the items in a local-script and checking for their updates in a boolean array. As you can see below, indices 0-499 update from the subscription, but 500-999 never update. Any idea what is happening here?

[webiq-sk]

Please provide the connect.log from the affected system (optimally in trace mode) so we can look into this. Without the log no analysis is possible.

[Sgilk]

I solved the problem here after reviewing the connect.log. 

[     warning |      io_extension_item]   error_code(): opcua:-2133131264:BadTooManyMonitoredItems

On the OPC UA server side, there was a limit of 500 monitored items per subscription.

There is one other piece of strange behavior. I am seeing that subscribed items often update multiple times before the entire set of items updates once. For example, if I have an array of 1000 items, item 1 may update twice before item 1000 updates once. There is nothing in the trace logs that indicates a related problem.

[webiq-sk]

You can create a Wireshark log (when not using OPC-UA encryption) and investigate if your OPC UA server is the reason or WebIQ server. Please note that in OPC UA the OPC-UA server always sends updates as it's not a pull meachanism, but a subscription mechanism where the server sends the data to the client.

[Sgilk]

Is this possible when the OPC UA server and WebIQ server are both running on the ctrlX CORE? The wireshark traffic I see to my PC WebIQ client is all TCP and TLS.

[webiq-sk]

Probably not, then simply switch to unencrypted traffic and use WebIQ on a local system on the network - then you should be able to diagnose this.