OPC client-server connection problems

[Fernando84]

Hi everyone, I'm trying to connect to a OPC UA server using my geo scada as OPC UA client, but I have an error, when I want to select the server URL, it shows the servers but they have a red symbol on and I can't select one of them. Any suggestion?

[MarkPitout]

If you see that red icon, then the Discovery Server object is unable to contact the OPC-UA server. There may be a few reasons for this:

1. You might have a firewall blocking access.

2. You might not have defined the Discovery Server URL correctly.

In the 1st screenshot attached, I've defined two discovery servers: 1.) BMENUA0100 and 2.) EcoStruxure OPC-UA Server Expert. My BMENUA0100 is switched off and therefore not reachable, but the EcoStruxure OPC-UA Server is running at the endpoint shown bottom right of the screenshot. It is important to use the full endpoint of the server you are trying to connect to.

For further diagnostics see the OPC-UA coms driver log file (2nd screen shot):

1. Go to Server Status

2. Expand the server tree and go to Modules

3. Right-click on OPCUA and select the "View DriverOPCUA_xxx.log" option.

4. Scroll through this log and look for messages like "BadTimeout" etc.

A discovery server object that succeeds in connecting to an OPC-UA server should show the message "FindServers succeeded" (3rd screenshot).