jfl

Hello, Thank you to dwisti and Karl Rony for your answers. From your point of view, with this type of solution, are the performance of OPC exchanges far better than with Datasocket API ? A little question to Karl Rony : on OPCware web site there's a comment on the use of "OPCWare Client Developer" with labVIEW. It has been written by a certain "- KR, Instrument Engineer & LabVIEW Programmer". Is it a coincidence or is it your comment ? Regards.

Hello Tom Eilers, Thank you for your message, but I think it doesn't answer to my question. I'll try to be more precise : Effectively, the shared variable engine included in LabVIEW 8 is an OPC server. But the application that I want to develop with LabVIEW must communicate (as an OPC client) with an existing remote OPC server which is not LabVIEW. The topic of my question was to know if someone had already developed, with LabVIEW, an OPC client based on the automation wrapper of the OPC foundation and if the performance are better than with DataSocket API (personally, I think it will be...) Regards -- jfl

Hello, I have to develop a LabVIEW application involving a certain number of OPC items (typically one or two hundred items). From what I read on NI forums and on LAVA.org, I have mainly seen two types of solution : Datasocket or DSC module. - DataSocket API : it seems that it doesn't suit very well in this case (the number is a bit to high : the creation of one OPC group at each "DataSocket Open" can lead to performance issues). - DSC : the inconvenient is the price of the license and I think DSC has many functionalities that I don't need for my application (Data Logging, HMI, Database Connectivity...). I think that an intermediate solution can be to implement the automation wrapper of the OPC foundation. My idea is to use from LabVIEW the DLL "OPCDAAuto.dll" which exposes an Automation COM interface. From what I understand of LabVIEW, ActiveX and DCOM, there shouldn't be feasibility issues. I wanted to know if someone had already implemented this kind of solution and what are the capacities in term of performance. Thank you by advance to anyone able to give me an advice on this topic. Best regards. -- jfl