We have our OPC UA Server configured on 8.1.4 and have successfully connected with an external OPC-UA Client. Updating the external client with a few hundred opcItemPaths we see the values update as we would expect. However, we want to have ~6k subscriptions to tags running and stop seeing it work somewhere after 1,000 we get an error:
OPCUAReader[0] Failed to read points from server due to System.AggregateException: One or more errors occurred. (Timeout occurred while processing the request.)
I’m new to Ignition, but we’ve used this OPC-UA client to integrate into other servers fine where we are getting values on thousands of points every second. We’ve batched the reads in chunks of a 300 every 10 seconds to allow for more subsriptions, but I’ve never had to configure the batch so small before, it’s usually like 3k.
I’m just looking to see if there is some known limitation on 8.1.4’s OPC UA, or just to be pointed in the right direction if it sounds like we must be doing something wrong.
Your client should create a subscription and monitored items, rather than what sounds like issuing periodic read requests.
Other than that - a bit more information is needed before I can give more advice. What tags are you accessing? From what devices? Is it reads or subscriptions? Can you get a Wireshark capture?
Also worth upgrading to the latest 8.1.x when you have a chance. Nothing in particular stands out, but 8.1.4 is old and early.
Thank you, Kevin. Apologies for the poorly worded post. The client is issuing read requests, I’ll check if we can change it to subscriptions.
Upgrade is scheduled, just unfortunately happening to this particular server later in the year. I’ll work on getting the rest of the details to help the troubleshooting.
The main reason reads would be slow like that would be if a lot the tags you are reading are either device tags (tags directly from the device rather than tags defined in Ignition and exposed via Exposed Tags), which means you have to wait for comms from each PLC the tags are from, or because the tags are from remote tag providers from other remote Ignition gateways, which is relatively slow (waiting for comms again) and was even slower in earlier versions.