OPC UA

[DAXIA]

Hi, engineers, I have a problem recently。

I connect crio9038 in labview2017 and run OPC UA demo. The OPC UA server is created in RT, which can connect to the OPC UA client of PC. however, in the PC resume server, when the client is created in RT, RT prompts 356698, and the host cannot be found. Ensure that the host is valid or change the IP address

Why are errors prompted after conversion? I hope to get the suggestions of engineers

[rolfk]

Your wording is quite confused. In network communication a server normally never connects to a client but always the other way around.

So when you run the server on the cRIO your client from the PC can connect fine. And when you run the server on the PC, the client on the cRIO can't connect to the server, right?

That sounds VERY much like your firewall on your PC is doing its job as it is meant to do. When the client is on the PC, the connection is "outgoing". Most firewalls are configured to allow outgoing connections without much of a hick and also allow the returning data packets on that connection. But for incoming connections, well configured firewalls will pretty much block anything and just sinkhole the packages without even sending as much as an acknowledge. This is to leave the potential attacker completely in the dark if there is even a network connection available at that address that deserves more attention.

You can test that by, very briefly, disabling your firewall and testing that example again. No matter what the result, enable it ASAP again. The internet out there is anything but a cosy place, in fact it is a war field that you do not want to let into your PC if at all possible. If this test shows that it works then you have to enable a rule in your firewall to allow incoming traffic on the port(s) used by OPC UA.

Depending on the OPC UA services you want to use you have to enable one or more of these ports:

http://opcfoundation.github.io/UA-.NETStandard/help/firewall_settings.htm

[DAXIA]

emm, I'm very sorry. I'm a student majoring in mechanics. I don't know enough about the contents related to communication, so many details are not very clear, which leads to the nonstandard description of my problem and brings you trouble.

Of course, your guess is completely correct. I also thought about whether this error was caused by the setting of the firewall. I'm trying to solve it according to what you said.

Thank you for your suggestion.