Data transfer between LabView and VB.net

[puneguy]

Hello,

I want to have two applications running, one labview and another vb.net. The LV application consists of two controls a,b & one indicator c.

The logic is a+b=c which is a WHILE loop. From VB.NET I want to pass values of a, b to LV and get back the result 'c' may be through event structure in VB.NET.

Please let me know how to achieve this.

[MarcoMauri]

Hi!

Here you can find a starting point for .NET event handling in Labview:

https://forums.ni.com/t5/Developer-Center-Resources/Register-Callback-VIs-for-NET-Events-in-LabVIEW/...

You could,as an alternative, use Labview to build a DLL and call it from VB.NET or vice-versa.

As a third alternative the programs can communicate via TCP/IP or UDP or through a web service.

Regards,

Marco

[puneguy]

Hi,

I am looking for solution using activex server  in LV. Actually I am able to create LV activex server and register it with vb.net.

In fact I am also able to start the VI and see that the while loop is running. But unable to pass values to the control a and b.

Can somebody explain me using activex server properties & methods how to pass the values to controls.

Rgds,

[MarcoMauri]

There should be an example for you, as noted in the last paragraph of this link: https://www.ni.com/docs/en-US/bundle/labview/page/activating-labview-as-an-activex-server.html

Marco

[puneguy]

Marco, ur support is appreciated !

However the example is for visual basic 6. Also I know how to call dll, exe from vb.

What I am trying to do is use the methods & properties ( OOPS ) of Virtual Instrument / LV application to transfer data.

The attached screenshot will help you understand my problem better. Here I am trying to stop the execution of counter increment logic in LV from vb.net

Can you suggest solution ?

[MarcoMauri]

Hi!

In sub Button1_Click you are defining and initializing local va1 and vi1.

That's probably why the Button2_click is not working as you want.

Always use the global va1 and vi1 and everything should be fine.

Regards,

Marco

[puneguy · Accepted solution]

Yeap U r right !

Thank you Marco.

[MarcoMauri]

Glad to see you solved your issue!

If you want you can provide some beer kudos.

Marco

[puneguy]

My pleasure !