Linking Visual C++ program with Labview (real time)

[jw81]

I have a Visual C++ program to generate output voltage value. May I know how to connect the program with Labview (in real time) so that Labview will receives these output from my program and process them?

More detailed description:

My C++ program will generates about 100 values of voltages between -2V to 2V. I am required to send these voltages to Labview. From LabView, signals will be sent to voltage supplier to supply voltage to the machine.

I have difficulty linking my program with Labview in real time.


Thanks a million.

Thanks

[pjtanz]

Hello there,

If you are using the LabVIEW Real-time module, then the real-time portion of your code will run on a separate system running a Non-Windows Based Real-time Operating System. Obviously, the Visual C++ code cannot be run on that system.

What you can do, however, is create a LabVIEW VI that runs on a Windows host PC and interfaces with Visual C++. Then, this host VI can communicate parameters to the Real-time system. These can be the parameters that were generated by your Visual C++ code.

If you are not using the LabVIEW Real-time module, the problem becomes simpler. You will just need to build your Visual C++ code into a .dll that can then be called from LabVIEW. After that, you would use the "call library" function to make calls to the .dll. There is a great example that ships with LabVIEW 7.X called "call DLL.vi". This example is a comprehensive look at calling .dll files from LabVIEW, and it think that it will point you in the right direction.

I hope that this helps.

Regards,
P.J.
National Instruments

[jw81]

I am running a window MFC application. I noticed the call DLL function in Labview however I only have MFC based .exe. Is there a method to let my .exe communicate with Labview?

[pjtanz]

There is an example frogram that deals with MFC calls to LabVIEW VIs. [link removed; example no longer available] I hope that this helps.

P.J.
National Instruments