Connecting two OPC UA servers through Labview?

[pato7]

Hello,

I want to ask if its possible through labview to connect two OPC UA servers. if yes, is it possible to do it on the same PC or the two servers should be on separate windows?

Thank you.

Best Regards.

[smithd]

if you mean connecting TO two opc ua servers I would guess yes.You specify what you want to connect to through the url.

If you mean hosting two servers, I would guess yes but they would have to use separate ports. If this is what you were asking, why do you want two servers? I would assume in most cases people want their scada server to be the source of all truth, not the source of some of the truth.

[pato7]

15 hours ago, smithd said:

if you mean connecting TO two opc ua servers I would guess yes.You specify what you want to connect to through the url.

If you mean hosting two servers, I would guess yes but they would have to use separate ports. If this is what you were asking, why do you want two servers? I would assume in most cases people want their scada server to be the source of all truth, not the source of some of the truth.

Thank you for your reply. I meant for example if I have a server with 5 sensors related to it and another server with 10 sensors related to it. Is it possible to connect these two servers or let them communicate and share data in a labview VI on the same PC? how? is there a special VI for that? can I use the "connect" Vi found at the OPC UA client palette list?

Thank you.

[JKSH]

12 hours ago, pato7 said:

for example if I have a server with 5 sensors related to it and another server with 10 sensors related to it. Is it possible to connect these two servers or let them communicate and share data in a labview VI on the same PC?

Not directly. Servers are designed to provide data to Clients, not to other servers.

If you want, you can write code that uses a Client to read reads the data from one server, and then copy the data to the other Server. However, I suspect you should re-design your code instead.

Why do you have 2 separate servers on the same PC? Would it make sense to only have one Server, and put your sensor data under different Folders?

Edited June 5, 2016 by JKSH
Don't need Client for reading, if both servers are in the same application

[pato7]

1 minute ago, JKSH said:

Not directly. Servers are designed to provide data to Clients, not to other servers.

If you want, you can write code that uses a Client to read the data from one server, and then copy the data to the other Server. However, I suspect you should re-design your code instead.

Why do you have 2 separate servers on the same PC? Would it make sense to only have one Server, and put your sensor data under different Folders?

Thanks for your reply. I am designing prototype data structures for some process and I was wondering if using two servers to describe the system is a possible solution to include between the suggested prototypes. Might not be the best solution but I was making sure if its possible through labview because OPC UA by definition allows communication between server-server or server-client in general.

Thank you.

[smithd]

On 6/4/2016 at 10:37 PM, pato7 said:

OPC UA by definition allows communication between server-server or server-client in general.

I can't find any validation of this statement. From what I can tell, other solutions are similar to what JKSH suggested. For example: https://www.kepware.com/products/kepserverex/drivers/opc-ua-client/. I would also assume there is required to be a client-server interaction since OPC UA is capable of going over HTTP, which is inherently client-server. Are you sure server-server exists for OPC UA?

 

[Rolf Kalbermatter]

Not sure about OPC UA details but generally server to server doesn't make much sense and simply makes setup of the system more complex. Possibly OPC UA allows for some hybrid configuration where a server can be configured to relay data from another server as some sort of gateway between differently secured network segments, but other than that I see no real benefit in complicating the server configuration by adding the possibility to let a server relay data from another server.

[drjdpowell]

On June 4, 2016 at 6:28 PM, pato7 said:

Thank you for your reply. I meant for example if I have a server with 5 sensors related to it and another server with 10 sensors related to it. Is it possible to connect these two servers or let them communicate and share data in a labview VI on the same PC? how? is there a special VI for that? can I use the "connect" Vi found at the OPC UA client palette list?

It’s unclear to me what people in this conversation are meaning by the “server”.  If the OP means a LabVIEW program that is serving up data via a created OPC server, then that same program should also be able to connect to other servers via the OPC client VIs.