Old/New comparison in OPC UA Server

WalitziS · Post by **WalitziS** » Fri Apr 28, 2017 10:18 am

Hello,

Our system is WinCC OA 3.11 SP1 running on RHEL 6.
We started an OPC UA Server to connect to external applications which each acting as an OPC UA Client.
When the same set point value is sent twice from the external applications, the second telegram is not entered in the data model (time stamp does not change) and the set point is not output to the connected outstation.
Does anybody know about this problem and how to solve it?

Regards,
Sabine Walitzi

Gertjan van Schijndel · Wed May 03, 2017 4:59 pm

I have tested this issue with WinCC OA 3.15+P002 on windows. But when I write the same value for a second time the time stamp does change.

The OPC UA server uses the debug flags API_USR1-API_USR3 (10-12) & DRV_USR1 (25). The debug flags API_USR2 & API_USR3 should provide at least more information regarding incoming values.

WalitziS · Post by **WalitziS** » Thu May 04, 2017 8:21 am

I will activate the debug flags and see if I get any more information.
Thanx!

WalitziS · Post by **WalitziS** » Tue May 23, 2017 8:33 am

Activating the mentioned debugging flags caused our OPC UA Server to crash.
We circumvented the old/new comparison by sending first value "0" and then the correct value.

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