How to create a OPC Server

[galtech]

I must create a OPC serveur to distribute any value to other automation application.
I now how to access to a OPC server (like the NI Demo server) but this time i must do my hown OPC server

Thanks in advance and best regards

(sorry for my english but i speek usually french!)

Yves

[alexBC]

Yves

Two possible solution come into my mind:

1) You could use the LabVIEW DSC module, which is also an OPC Server. Then you define so-called "memory tags" within DSC and access them from your LabVIEW code using the read and write tag VI's or the logos protocol. What is annoying with that solution, is that DSC has no programmatic tag creation, so you must setup the tags manually outside of your code.

2) Search the net for the "FactorySoft OPC Server Rapid Development Kit". Using that toolkit, a few years ago we programmed an OPC Server which can be embedded into LV code using the "Call Library Function Node". I am still using it. The advantages are that tags can be programmatically created in the LV code, the OPC server can be distributed royalty free (DSC=$$)and the OPC server will consist just of 3 small dll's which are easy to install. However some C/C++ knowledge and a compiler will are required.

J' espère, que ces informations sont utiles pour toi

Alexandre

[galtech]

Merci Alexandre... cela me parait une bonne piste !

[*Peter*]

Thanks for the Information.

We now use the Simulation OPC Server from Iconics.

Nice free OPC server with a lot of feautures.

gtx Peter

[Vasilich2004]

Hi,

Iconics license give permission just for one personal computer.

FactorySoft doesn't support the product anymore and suggest to buy another tool.

Who knows any other OPC product for free?

Maybe another client-server (build simple distributed system) protocol?

[Wiebe@CARYA]

It should be possible with lightOPC, a free and open source OPC server toolkit: http://www.ipi.ac.ru/lab43/lopc-en.html .


After downloading the binaries, and strarting the sample exe, I did see a new OPC server, and I could connect to it with a datasocket (I've LV7.1 on this PC).


Unfortunatelly, there is do documentation what so ever... It should be possible to make a dll that LabVIEW can interface with, so we could build our own LabVIEW OPC Server...


But shouldn't LV8> have a build in OPC Server, when you use Shared Variables?


Regards,


Wiebe.

[chrisger]

hi there

i suggest the free OPC demo server from softing: http://www.softing.com/home/de/industrial-automation/downloads/drivers-demos.php?navanchor=3010470

this server ist free and allows cration of dynamic items via a simple spreadsheet file. documentation is also delivered.

[Craig_D]

Wiebe,

You are correct.  The shared variable engine itself is an OPC server.  Therefore, the easiest way to publish LabVIEW data through OPC is to use shared variables.  See this KnowledgeBase article for more information on how to do this.

Regards,

Craig D

Applications Engineer

National Instruments

[Vasilich2004]

At first, thank you All.

I think that Shared variable as protocol is fine. But I don't see way in LabVIEW to add Shared variable programmaticly. I didn't look on Measurement Studio but suppose there is not way there also.

I know about lightOPC from Russia and I has pointed that it was done in 2000. I used something from Softing in 1999 I will look on link.

I also looked on ICAPLECS and PCaPAC conferences. I didn't find something new ... LabVIEW, OPC, Corba, EPICS, PVSII ...

[Craig_D]

It is possible to programmatically create shared variables and add them to a library using property and invoke nodes.  See this example program on how to do this.

Of course, this is much easier using the Datalogging and Supervisory Control (DSC) Module.  See this document from the DSC help for more information on how this is done.

Regards,

Craig D

Applications Engineer

National Instruments