Why don't I see the serial port names such as COMx? I have to use ASRLx::INSTR

[_S_G]

I created an installer for a LabVIEW application and included the NI VISA drivers in it because my application uses serial ports.  However, on the target machine, I do not see the self populating list of serial devices.  I have to type in ASRL1::INSTR instead of COM1.

Why is this?  The target machine has NI VISA and the NI VISA Runtime Engine installed on it.

Message Edited by S G on 03-11-2008 06:35 PM

Message Edited by S G on 03-11-2008 06:36 PM

[Ray.R]

It has to do with the alias name to COM1.  I can't remember exactly in which ini file it resides, but I seem to recall that you can change it within MAX.

I'll try to find the ini file.  Or where in MAX to change it.

[Ray.R]

I used to change the alias in the ini file, but that was many years ago. 😉

Open Measurement & Automation Explorer (MAX) and select your serial port.  The physical name is ASRL1::INSTR, but you can assign an alias COM1 as shown in the image below. 

Message Edited by JoeLabView on 03-11-2008 09:43 PM

[_S_G]

Thanks.  However, why did I not need to do that on my development system?  My development system even finds new serial ports that I plug in and automatically names them.  For instance, when I plug in a USB to serial converter, it shows up on my application as COM3.

Message Edited by S G on 03-12-2008 01:08 PM

[Ray.R]

That's a good question...  I don't know the answer..

I did see that issue before which is where I modified the ini file.  But I think the first time I saw it was with the Developper Suite and LV6.1.  Plus I saw it again with CVI.  So, I don't know what is the common denominator..

Glad it helped,

RayR

[Dennis_Knutson]

SG,

What is the version of LabVIEW and NI-VISA that you are using? If LabVIEW 8.x and the VISA that came with those, you can only select the VISA run-time but this should still work. You can optionally select to export your MAX configuration and this should also include the aliases (ComX).

With some older versions of NI-VISA, installing just the VISA run-time did not force VISA to assign the aliases to a com port. You had to include the visaconf.ini file from the development pc.

[_S_G]

I have NI VISA version 4.2, and LabVIEW 8.5.

[Dennis_Knutson]

Then I'm unsure what might be wrong. You can try adding the export MAXA option and see if that makes a difference. I recently created an installer for an 8.5 program and NI-VISA. On the vast majority of the pc's everything was flawless. On some though, I had problems with the com resources. It was a different symptom but it seems like it was related to a very old version of VISA that had been previously installed. We did the install on a new machine and it worked.

[Ray.R]

Dennis is right 🙂  Not that I would ever doubt him 😄

The newer version of LV do not have visaconf.ini, so please ignore some of the info from my original post. 

I did find an old version which contained the following:

[VISA-CONFIG]
MinAsyncCount = 512
SharedMemSize = 196608
MaxNumResources = 256
NumSystemSems = 512
NumProcessSems = 256
UnloadPassports = 0
ShowRegisteredDevOnly = 1

[ALIASES]
Alias0 = "'LPT1','ASRL10::INSTR'"
Alias1 = "'COM1','ASRL1::INSTR'"
NumAliases = 2

BTW, Dennis, do you know where that info is hidden with the newer version?  I can always do a search for COM1 as a text string..  This is just my personal curiosity.  The last time I modified the visaconf.ini file was for a CVI project back in 2004, which was for legacy code dating back to 2001. 

[Dennis_Knutson]

It's still in visaconf.in but the location of the file has moved. It's now in c:\Documents and Settings\All Users\Application Data\National Instruments\NIvisa.

When I had the recent problem with my installer, it turns out that the upgrade to the latest VISA did not remove the visconf from the c:\vxipnp\etc. folder. I could do some wmanual stuff and clean up the old folder and my app started to work.