OPC UA max count of transferred values in one cycle

AlesChrast · 3 weeks ago

Dear all,

Setup:
CoreX 3 (2.06) - OPC UA (2.6.3) - WinCC V8 Update 5

Our CoreX 3 communicates with HMI based on WinCC V8 Update 5.
We are on commissioning and during the process I noticed that when we open two screens with a lot of tags on the same PC (two different displays) some of the tags don't load. (0x04 - communication error, addressing error (information from WinCC). All the tags are called at the same time, so I assume the problem is due to the OPC UA server-side limit on the call values. Of course, correct me if I'm wrong.

Does OPC UA have any such limit that can be changed?

Attached printscreen where you can see the behavior

I would be very grateful for any advice. Thanks in advance

Sgilk · 3 weeks ago

Hi @AlesChrast ,

Settings for the OPC UA server can be found in the ctrlX CORE Web UI.

How are these values being read? There are a number of settings that could affect this behavior.

AlesChrast · 3 weeks ago

Yes, I Know about this settings. There is value Maximun number of Monitored Items Per Subcription, when I changed it, after refreshing the screen it went back to the previous value. I used the datalayer for changing this value, now it is working.

NoRisk4Project · 2 weeks ago

Hello,

the basic limits of the supported services are listed inside the OPC UA server application manual (https://docs.automation.boschrexroth.com/doc/412150158/properties/latest/en/ )

Unfortunately, the max limits of the OPC UA server, are not yet listed inside the documentation:

Sessions: Max 50 Sessions / Max 50 Sessions for Subscriptions

Subscription: Max 150 Subscriptions per Session (Max total 150) / Max 150 Publish Service requests per Session

Monitor Items: Max 2000 per Subscriptions (Max total 5000)

Monitor QueueSize: Max size 500