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FindServersOnNetwork service?

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09 Dec 2020 19:32 #9250 by support
If you do not get any error, but just an empty list, this means that the LDS-ME is not returning any servers to us and that's beyond our concern.

Unless, of course, you have some other OPC client that uses FindServersOnNetwork to connect to LDS-ME and DOES return some servers - which would then require investigation as to why QuickOPC's result are different.

But in general, for LDS-ME to return servers:
- The servers running on the same machine as the LDS-ME need to be configured to register with LDS-ME - which normally also includes configuring the UA security for them because registering the server with LDS-ME is security sensitive.
- If there are other LDS-ME servers on the network, the network must allow the proper mDNS (UDP) traffic between them.
- Servers on other machines need to be configured to register with their respective LDS-ME servers on those machines.

Best regards

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09 Dec 2020 18:51 #9249 by micham
Hi,

Thank you for your answer.

The local discovery server is running on my machine. When I am using "localhost" I don't get any UA server in the list.

The discoveryElementCollection is empty.

I appreciate your advise.

Michael

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09 Dec 2020 18:41 #9248 by support
For any real application, it MUST be something else. Real application is not interested in servers on our demo network.

It must be the name of the host where you/the customer have installed the LDS-ME server.

It can be "localhost" if the LDS-ME is on the same computer as the client, or some other host name.
This is where the DiscoverNetworkServers methods gets the information from.

Best regards

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09 Dec 2020 18:18 #9247 by micham
Hi,

My question was what is the meaning of the "opcua.demo-this.com" parameter?

discoveryElementCollection = client.DiscoverNetworkServers("opcua.demo-this.com")

Can it be something else?

I have other OPC UA servers, for example PROSYS but the discovery using your sample code doesn't discover it.

Thanks,

Michael

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09 Dec 2020 18:08 #9246 by support
Not sure what other servers you wants to see. These are servers on our demo network, so it is up to us who decide which servers gets listed. If you are referring to the fact that we also have a GDS demo server, then this one is not probably properly registering itself with LDS-ME due to an omission in the configuration, but that does not have any negative impact on the purpose of the demo apps and the examples that use them.

Bets regards

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09 Dec 2020 18:05 #9245 by support
As a first argument, you need to pass in the host name of the machine that runs the LDS-ME. "opcua.demo-this.com" is used in our examples, as it is the host name where we run our demo LDS-ME.

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09 Dec 2020 16:36 #9244 by micham
See the result I get. I don't see other servers...

Thanks.

Michael
Attachments:

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09 Dec 2020 16:30 #9243 by micham
Hi,
Thank you.

What should be the parameters for the function: discoveryElementCollection = client.DiscoverNetworkServers() ?

Currently it is: "opcua.demo-this.com", flat:=False

Thank you.

Michael

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09 Dec 2020 05:22 #9235 by micham
Hi,

Is it possible to browse for OPC UA server using QuickOPC client .Net using the FindServersOnNetwork service?

Thank you.

Michael

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