OPC UA Secure Connection doesn't work

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1

Hi,
I am trying to establish a secure OPC UA connection between a B&R OPC UA Server (Automation Studio 6.5.1.7) and a Siemens S7-1500 OPC UA Client using Sign & Encrypt.
Communication without security works correctly.

However, when I connect from the Siemens PLC, the connection is established briefly and then immediately disconnects.
On the B&R side I configured the following:

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• Picture 1: Under Certificate Store Configuration I selected SSL Configuration. The B&R server uses a self-created server certificate and private key.
• Picture 2: In the SSL configuration, the B&R server certificate is configured as the own certificate. Under Trusted certificates I imported the Siemens PLC client certificate.

I followed the steps from an existing B&R Community post (@UAExpert, mappView: How to make a secure OPCUA connection to OPCUA server with communication partner validation) about configuring certificates, so I believe the certificate setup should be correct.
Is there anything else that has to be configured for secure communication with a Siemens OPC UA client?

Thanks in advance!

2

Hi Lisa,

Please check the B&R PLCs connectivity logger, opened in Automation Studio when connected to the PLC with CTRL + L or from the menus Open → Logger. It most likely has a message related to the disconnection.

Also when using certificates it is important that all participants have their times set correctly. You can set the B&R PLCs time from Automation Studio from the top menu Online → Info. (Or configure it to retrieve a time from an NTP server in the PLCs configuration).

3

Hi Tommi,

Thank you very much for your help! It turned out that the issue was caused by the incorrect system time. Now the secure OPC UA communication works correctly. :slight_smile: