Launching Wrong Version of LabVIEW

[hooovahh]

Ok lets say I have LabVIEW 7.1, and LabVIEW 8.0 installed in a Windows machine. If I run LabVIEW 7.1, then run LabVIEW 8.0, then minimize both, then go to the start menu and run LabVIEW 7.1 again, the LabVIEW 8.0 window will be brought up. To me this is a bug. A larger bug (which is related to this one) is if I run the command line "C:\Program Files\National Instruments\LabVIEW 7.1\LabVIEW.exe" "C:\test.vi" it will open the test.vi in the 8.0 version of LabVIEW.

I think NI's mentality is that LabVIEW should remember the last version that was ran, for convience when opening new code. But I know what version of LabVIEW I want to run, based on predefined shortcuts and installation paths.

So does anyone know of a way, to prevent LabVIEW from remembering what version was last ran? I've tried adding the "RegisterExtensions=False" key in the LabVIEW.ini files (it was suggested at NI's forum this may fix it) I've also probed the Windows registry and any any reference to "LabVIEW 8.0\LabVIEW.exe" I replace (one at a time) with "LabVIEW 7.1\LabVIEW.exe" and it did not help. Thanks.

[Yair]

I seem to remember there was a bug around 8.0 or 8.2 in the way LabVIEW handled this, but I don't remember the specifics.

If you want to work with multiple versions, you could try Dataact's version chooser. I never used it myself, so I can't comment on its functionality.

[hooovahh]

I have never heard of Dataact's program for choosing LabVIEW versions. I found the link here if anyone is interested.

http://dataact.com/downloads.htm

However the application has the same problem I asked about. If you have the LabVIEW choosing program installed, and double click a file, it will ask what version of LV to run (this works fine) if you the double click any other LabVIEW file it will open it in the same version of LabVIEW that is already open. Basically their program only works if you have no versions of LabVIEW open which for me at least, is rare.

Data Act explains why in their FAQ the software behaves like this. (FAQ number 2)

http://dataact.com/LVC_Help/Using_FAQs.htm

Something dealing with DDE between versions of LabVIEW. So it looks like there's nothing that can be done about this.

[Jim Kring]

Ok lets say I have LabVIEW 7.1, and LabVIEW 8.0 installed in a Windows machine. If I run LabVIEW 7.1, then run LabVIEW 8.0, then minimize both, then go to the start menu and run LabVIEW 7.1 again, the LabVIEW 8.0 window will be brought up. To me this is a bug. A larger bug (which is related to this one) is if I run the command line "C:\Program Files\National Instruments\LabVIEW 7.1\LabVIEW.exe" "C:\test.vi" it will open the test.vi in the 8.0 version of LabVIEW.

I think NI's mentality is that LabVIEW should remember the last version that was ran, for convience when opening new code. But I know what version of LabVIEW I want to run, based on predefined shortcuts and installation paths.

So does anyone know of a way, to prevent LabVIEW from remembering what version was last ran? I've tried adding the "RegisterExtensions=False" key in the LabVIEW.ini files (it was suggested at NI's forum this may fix it) I've also probed the Windows registry and any any reference to "LabVIEW 8.0\LabVIEW.exe" I replace (one at a time) with "LabVIEW 7.1\LabVIEW.exe" and it did not help. Thanks.

I've seen this problem and I don't think there is a solution

Hopefully NI will fix it.

[Rolf Kalbermatter]

Ok lets say I have LabVIEW 7.1, and LabVIEW 8.0 installed in a Windows machine. If I run LabVIEW 7.1, then run LabVIEW 8.0, then minimize both, then go to the start menu and run LabVIEW 7.1 again, the LabVIEW 8.0 window will be brought up. To me this is a bug. A larger bug (which is related to this one) is if I run the command line "C:Program FilesNational InstrumentsLabVIEW 7.1LabVIEW.exe" "C:test.vi" it will open the test.vi in the 8.0 version of LabVIEW.

I think NI's mentality is that LabVIEW should remember the last version that was ran, for convience when opening new code. But I know what version of LabVIEW I want to run, based on predefined shortcuts and installation paths.

So does anyone know of a way, to prevent LabVIEW from remembering what version was last ran? I've tried adding the "RegisterExtensions=False" key in the LabVIEW.ini files (it was suggested at NI's forum this may fix it) I've also probed the Windows registry and any any reference to "LabVIEW 8.0LabVIEW.exe" I replace (one at a time) with "LabVIEW 7.1LabVIEW.exe" and it did not help. Thanks.

There is no way to fix that really as far as Windows goes. The reason is the limited file association based on file endings instead of Meta data as was used in the old Mac OS Classic Desktop interface. I think Mac OS X still supports that but they also went the path of basing most of the launching on file endings instead.

The registry defines which program should be started for a specific file ending and obviously you can not really register more than one primary application for a single ending. The specific problem you see is that the actual launching of a file in an already launched application is done through DDE. The registry defines for the file type a DDE server name and an application topic and the Windows shell (the part that basically sits above the actual Win32 API and where the File Explorer is the UI of) attempts to contact the registered application through DDE and if that succeeds it passes it the file path to open. On failure it launches the registered executable passing it the file path as argument instead.

LabVIEW uses the same DDE server name in all versions. You could say that this is a bug but unfortunately since the whole file association in Windows is based on file endings only and therefore a file traditionally only has one association there was very little use in trying to be smart and use versioned DDE server names. Recent Windows versions added a possibility to register multiple applications for the same file type but this is in fact at best a hack IMO. Microsoft itself does discourage to use DDE since about Windows NT4 for anything, although it is still the standard way of launching files into a running application. NI probably never has looked much into that anymore since it is both unsupported technology as far as MS is concerned and the registration of different LabVIEW versions for the same files would be mostly a hack anyhow as it is only a UI feature of the Explorer where you get multiple sub menu items under the Open right click menu. There is really no way to version automatic file launching for the same file type, simply because you can not do a 1 to n selection automatically.

The Datact version chooser in my opinion would have a chance to do the right thing although it is by far not trivial. The solution would be, and I was under the impression that was what it did, to use VI server to launch the file in a specific LabVIEW version. There are a few difficulties with this. The first is that someone would have to configure the actually installed LabVIEW versions somewhere although I think VIPM is currently able to do that automatically for most standard installations. The second is that the VI server protocol did have a version chance between 6.x and 7.0 and there was a limitiation that only an old client could connect to a new server or vice versa (I'm not sure anymore which direction it went).

The principle would be simple. When the user selects a specific version do launch a file in the Version Chooser it would try to contact that LabVIEW version over VI server (each installed LabVIEW version would need a different VI server TCP/IP port) and if that fails it would launch the executable and connect to it again. After that it would send the open command over the VI Server interface.

Rolf Kalbermatter