Did you ever get this to work?

[84berlinetta]

I am currently attempting to create a LabVIEW executable that can call one of two other LabVIEW executables, based on the customer requirements. I am having the same problem you have seen. I have attempted to make the call with both the "System exec" VI and the "Run Application" VI with no luck - both are giving me errors. As in your case, I can successfully call non-LabVIEW executables with no problem.

[mikeporter]

What are the errors that you are getting? That's the first thing we need to know. LV is not perfect, but if you give it a chance it will generally tell you something about what is going wrong.

Also, are all the various pieces of the system written in the same version of LV? How old are the applications you are trying to run? Did you write them as well?

Mike...

[84berlinetta]

Hi Mike,

I finally figured this thing out last night... it is related to operation under Windows 2000 or Windows XP - both of which I am using here. After much digging, I found a link on the NI site that included a download entitled "Run.vi". Although the subect and header information did not give a great lead-in to what the file was about, there was a great note that was enclosed with the VI:

"The start command in Windows 95/98/Me launches a file using its default application. To use this command in NT/2000, you must first call "cmd /x /c" to launch "start" in a new instance of the command interpreter with extensions enabled."

So, the full syntax for the "command" string to "System exec" under the newer OS would be:

cmd /x /c start "yourp
ath\yourfilename"
(with the quotes)

This syntax mimics the use of the "START", "RUN" feature in Windows.

Hope this post saves others a lot of time in the future.

Thanks for your response...

Mark

[JRA]

Did you find this in a KnowledgeBase on NI's site?

[84berlinetta]

JRA -
Here is the url for the information I found at Ni.com:

http://sine.ni.com/apps/we/niepd_web_display.DISPLAY_EPD4?p_guid=B123AE0CBAAF111EE034080020E74861&p_node=DZ52027&p_submitted=N&p_rank=&p_answer=&p_source=External

[JRA]

Thanks, Mark.

[mikeporter]

There was also a discussion thread about this a while back either here or on info-labview about the differences in calling conventions between newer and older versions of Windows.

Mike...