Problems with converting OPC UA to AE

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Problems with converting OPC UA to AE

Post by elsu »

We are traying out UA gateaway to translate OPC UA (Siemens OPC UA Server for WinnCC) into OPC Alarm and Events.
UaGateaway is configured according to the manual and it connects to OPC UA.
The problem is that when we use Matrikon OPC Explorer on UnifiedAutomation.UaGatewayAE we are not able to see alarms and events.
We are able to see Alarms and Events using UAexpert but only from OPC UA (Siemens OPC UA Server for WinnCC) server.
So OPC UA are sending to data to the server, we are able to connect to it with UaGateaway but bet cannot see anything on OPC A&E via Matrikon OPC explorer.

Any suggestions ?

Thank you, Eligijus

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Re: Problems with converting OPC UA to AE

Post by Support Team »

Hello Eligijus,

this problem is related to how event filters work in OPC classic and OPC UA. For each OPC UA EventType one OPC COM AE EventCategorie is created. The AE Client can then use those categories as part of the event filter. Now MatrikonOPCExplorer is using a rather unlucky default - it adds all categories to the filter which is the most inefficient way of NOT filtering for a specific type.
What happens is: The COM AE client creates a filter with a huge number of categories, UaGateway converts that to an OPC UA EventFilter and the server rejects the filter because it has too many elements.
We can not really blame one component in this chain to behave wrong and against the specification.
There is a simple workaround for this problem: Don't set a category filter. You can configure that in the "Add Subscription" dialog of MatrikonOPCExplorer.
Best regards
Unified Automation Support Team

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