Hello,

When you say that the PLC “does not communicate with ProSys OPC Sim Server” what exactly do you mean? Has it not been able to connect and create and activate a Session or is it just not able to read data after connecting?

In Simulation Server’s Expert Mode, which can be enabled from Options, you can use Sessions, Connection Log and Req/Res Log tabs to monitor connections from Clients. Sessions and Connection Log tabs can be used to check if a Client has successfully connected to the Server. Req/Res Log tab can be used to see the requests sent by the Client to Simulation Server and the responses sent by Simulation Server to the Client.

If the Session from the Client doesn’t appear in Sessions or Connection Log tabs, you can use the Req/Res Log tab to check why creating and activating a Session fails. To use the Req/Res Log tab, you need to select the Active check box on the upper left corner of the tab. We recommend that you don’t have any other Clients connected to Simulation Server while debugging with the tab to avoid including their requests in the log. You should see requests like CreateSession and ActivateSession in the log when attempting to connect with your Clien after you have activated the logging.

If nothing is appearing in the log when your Client attempts to connect, it means that it has not been able to create a SecureChannel with Simulation Server. In that case, you can either take a look at Simulation Server’s log (see the user manual for more information on its location in your file system) or you can use Wireshark. See https://www.prosysopc.com/blog/opc-ua-wireshark/ for instructions on how to capture OPC UA communication with Wireshark. If you’re running the applications on the same host, remember to select “Support loopback traffic” option when installing Wireshark. You can send the log and/or the Wireshark capture to simulation-server-support@prosysopc.com so that we can take a look.

If the Client has been able to create and activate a Session but fails to read data, then you can use Req/Res Log tab to see how Simulation Server responds to the Clients requests. You can click on Filter by type button to open a list of different requests types. If the Client is reading the values directly from Nodes, you can unselect everything except for Read. If the Client is subscribing to the values via Subscriptions and MonitoredItems, you can unselect everything except for CreateMonitoredItems, CreateSubscription, DeleteMonitoredItems, DeleteSubscription, ModifyMonitoredItems, ModifySubscription, Publish, Republish, SetMonitoringMode and SetPublishingMode. Note that you do not have to filter the requests, but it can be helpful if there are many unrelated requests, though in this case there might not be such requests.

Out of curiosity, why would your PLC need to read data from Simulation Server? Can you tell about your use case briefly if it is something you can share on a public forum?