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Labview 2009 Windows 7 com port issue



I am trying to run an executable program using the Labview 2009 32bit runtime engine on a computer with a 32bit chip using the windows 7 operating system.

The program uses Visa and communicates via the com port. In order to get the program to work (i.e comunicate via the com port) I have had to upload the 2009 device drivers DVD.

The same combination works when windows 7 is relaced with XP without the up loading of the drivers, ergo the problem must be down to using windows 7. Uploading all the drivers seems rather excessive so is there a single driver that I can use that will solve the program in future?





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Message 1 of 9

You need the LV 2009 runtime engine.  Since you are using the com ports, you also need the VISA runtime engine.


You can create an installer that will install your .exe file as well as those two runtime engines.

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Message 2 of 9

Thanks for advice and congratualtions on your new status.

As I said in my post I am using the LV 2009 runtime engine already and I'm intersted to know why this doesn't operate the com ports with Windows 7 so I'm assming that yuo are auggesting that the VISA runtime engine will solve this.


I will give it a try.





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Message 3 of 9

It has nothing to do with Windows 7.  The regular LV runtime engine gives you the code needed to run LabVIEW executables, but does not give the code needed to use the serial ports, no matter what version of Windows you are using.  The VISA runtime engine provides the code needed for a LV executable to work with the VISA serial ports.

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Message 4 of 9

I don't wish to question your doubtless superior knowledge in these matters but windows 7 must have some effect, consider the facts;


Labview executable + Runtime engine + Windows XP = communication via comms port.


Labview executable + Runtime engine + Windows 7 = no communication via comms port


The VISA runtime engine may be the difference but isn't required in XP.


Thank you for your help though and good luck Houston Texans on Sunday.








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Message 5 of 9
Your statement about xp is simply not true. A separate installation of VISA has always been required for every version of LabVIEW on every os.
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Message 6 of 9

@Dennis Knutson wrote:
Your statement about xp is simply not true. A separate installation of VISA has always been required for every version of LabVIEW on every os.

Nitpick: Only once VISA started being used. We used to have to deal with port VIs. (I shudder at the memory) Smiley Wink


To OP: Are you installing a version of VISA that's compatible with Windows 7? Check the NI-VISA driver version. Also, verify that the COM ports are available from the Windows Device Manager. Also, check to see if they show up in MAX.

Message 7 of 9

Some good advice you wrote, thanks. I had a similar problem, old 2009 VI and windows 7 and it crashed after 1-10 reads.

All worked in MAX to read consecutively (VISA test panel). However I noted if I checked the async box in MAX, then nothing worked.

So, in the "serial" I checked what I had (rightclick in block diagram), and it was async. So I changed to:

"Synchronous I/O Mode»Synchronous from the shortcut menu to read data synchronously. "

And now it works fine. 

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Message 8 of 9


Did you ever figure this out? I'm in the same situation. 

Thank you

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Message 9 of 9