How can I interface with an ActiveX DLL from LabVIEW?

[JoWhelan]

Hi,

I am new to both LabVIEW and would still refer to myself as a novice programming so apologies in advance for this basic line of questioning, but any help you can give would be much appreciated.

I would like to read data into LabVIEW from a data acquisition device that is currently read by VB applications. I have been provided with an ActiveX DLL and told that this should allow me to read the data into LabVIEW. Does anyone have any basic examples explaining how to make a .vi file to do this or can provide a little guidance? I have looked on the ni.com website but can only find quite complicated examples. 

So far I have just tried to do this using various functions on the ActiveX functions palette and following the instructions on this webpage (https://www.ni.com/docs/en-US/bundle/labview/page/using-activex-with-labview.html) but I keep getting the error message that "the property node has one or more invalid properties or uninitialized property items."

I have LabVIEW 8.0. I do not however have Visual Studio currently installed on my PC. Do I require this? And if so can you also advise on which version I should download as there seem to be millions available and they are all rather large...

Many thanks again in advance.

[smercurio_fc]

You would only need Visual Studio if you intend to recompile the DLL yourself, and for that you need the source code.

When you place the Property/Invoke nodes on the block diagram can you actually see the list of properties and methods for the DLL when you click on the node?

[JoWhelan]

Hi,

Many thanks for your reply, much appreciated. I just bumped into a LabVIEW expert who kindly took me through the process so now I am up and running.

Jo