Teststand and DDE

[Laurent Lars]

I created a Vi under Labview , which communicate through DDE with an instrument on the same Computer.
This VI works fine when launch from Labview.
If I introduce the Vi as a step into Teststand, Then the DDE connection doesn t work anymore... Do you have any idea why ?
Thanks

[Matt P.]

Hi Laurent Lars,

1. Have you considered using ActiveX instead of DDE?


2. What version of TestStand are you using?


3. Are you checking for errors in your LabVIEW code?

You might try stepping into your LabVIEW code and see if LabVIEW grabs the DDE connection or returns any errors.

Matt Pickard
Applications Engineer
National Instruments

Matt Pickard
Applications Engineer
National Instruments

[Scott_Richardson]

Laurent -
Check to see what thread the VI is set to run in. If it is not the GUI thread, you might want to see if the VI behaves any differently with TestStand if the thread preferences is the GUI thread.

In addition to the version of TestStand, what version of LabVIEW are you using?

Scott Richardson

[Laurent Lars]

Hi Matt,
I use teststand 2.0.1.
Labview code is ok, when the Vi is stand alone then it works fine.
I use DDE because the instrument is local(otherwise it should be GPIB), if you have an idea to workaround, please send it to me
Thanks
Laurent

[Laurent Lars]

Hi Scott
I use Lv 6.0.1
How do you check the thread the Vi is set to ?
thanks
Laurent

[Scott_Richardson]

I have LabVIEW 6.1 installed so it should be similar.

Select in LabVIEW File>>VI Properties to display the VI Properties dialog box. In the Category ring control select "Execution". Look at the Preferred Execution System setting. This typically defaults to "same as caller". Change this to "user interface" to see if this makes a difference when run in LabVIEW using TestStand.

Scott Richardson