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HyperTerminal sees a COM port but VISA does not

Hi elrathia,

 

Within MAX, you can navigate to Tools > NI-VISA > VISA Options. Then, you can select the Aliases category on the left. This should populate a list of all the VISA aliases in use and you can click Clear All Aliases. I hope this is what you were looking for. Thanks and have a great day!

 

Cheers, 
Carisa Leal 

Applications Engineer
National Instruments
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Message 21 of 41
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Thanks, Carisa. I was about to reply that this was shown in the very first reply by Jeff B. to my original post.

 

However, now that I got your ear: After clearing all the aliases, my LV program using VISA would not see the port (after clicking Refresh in the COM list box of course) UNTIL I manually add the COM port number that is shown in Device Manager in MAX.

 

This can be done in MAX 2 ways (at least):

 

1. Right click "Serial & Parallel" in the Configuration tree (under Devices and Interfaces) and select "Create New Port". A dialog box (wizard) opens where you can assign an ASRL number and the Serial Binding to a port.

 

2. This can also be done in the same screen where you clear the aliases by Adding an alias.

 

My question and problem is why does this procedure to manually add or create an alias have to be done? I would think that after clearing all aliases, when new COM ports are installed, it should automatically pick them up, just like it does originally (with a clean install). Can you look into this and reply?

 

Thanks,

Ed

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Message 22 of 41
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Hi Ed,

 

To my knowledge, I believe the procedure needs to be done manually so none of the aliases are rewritten unexpectedly. Additionally, it may also have something to do with the device manager having already identified previous devices.

 

Thanks,

Carisa Leal

 

Applications Engineer
National Instruments
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Message 23 of 41
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Carisa,

 

When LabView is first installed and MAX is run, there is a list comprising "ASRL1:INSTR" alias "COM1" up to (on my PC) "ASRL57:INSTR" alias "COM57", then there is one more: "ASRL256:INSTR" alias "COM256". (Remember I said we were up to COM891 when it stopped working!) That information must be stored somewhere. I searched the registry and the C:\Program Files\National Instruments folder and it is not there. When you modify or delete assignments and click the 'Save' icon (button), can you find out where that is stored? It would be nice if we could edit that file rather than manually add them all back. (Also, it would be nice if MAX had a "Restore Defaults" button.)

 

Another question: Would installing and reinstalling the entire LabView package would not clear the assignments back to defaults? (After uninstalling it would probably be wise to delete the C:\Program Files\National Instruments folder).

 

Thank you,

Ed

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Message 24 of 41
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Hi Ed,

 

The VISA aliases should be saved in the visaconf.ini file. This article elaborates on where it is saved: http://digital.ni.com/public.nsf/allkb/F02B2BF8943A31D786257393005D16F1

 

If you would like to submit a product suggestion, I encourage you to post on our Idea Exchange found here: http://forums.ni.com/t5/LabVIEW-Idea-Exchange/idb-p/labviewideas

 

I hope this helps. Have a great day!

 

Thanks,

Carisa Leal

Applications Engineer
National Instruments
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Message 25 of 41
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Carisa,

 

Thank you. I remember reading about that ini file but couldn't remember it's name or where it was. I didn't think of searching the Documents and Settings folder!

 

BTW, my file says "MaxNumResources = 512" not 256 as it said somewhere else in your documentation, but our system allowed up to about 890.

 

Anyway, I don't want to clear all the aliases on my PC as a test, but if I did would the list of "interfaces" ("Interface0 = 1" through "Interface255 = 1") be cleared or not?

 

Or maybe it would be the aliases list. My last one is "Alias47 = "'COM57','ASRL57::INSTR'"" and the next line says "NumAliases = 48".

 

In other words, do you know if manually editing the file would work as when LabView was first installed? I'm also wondering if the installation DVD's has the original visaconf.ini file that could be used instead of editing the existing file? I'm wondering if VISA may read that file and use it in conjunction with registry information, so I'm not sure if manually editing it would work. Can you find this out?

 

Ed

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Message 26 of 41
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Carisa - One more thing. You didn't answer my question: Would uninstalling and reinstalling LabView clear the assignments back to defaults? (Our Production PC's only have the run-time engine installed.) Maybe the procedure would be to reinstall after running Device Remover? Do you know?

 

(BTW, I searched the DVD's and the file is not there. It must be compressed in one of the installer files.)

 

Ed

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In my previous post I meant to say "uninstalling and reinstalling the NI-VISA component" not LabView per se.

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Message 28 of 41
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Hi Ed,

 

The visaconf.ini file should be inside of your NI VISA folder, wherever you have that installed. Perhaps doing a wide search through your computer could find it. If you clear all the aliases, the interface list would still be there, but the aliases list would not.

 

If you manually edit the ini file, it will show up in MAX. I am unable to test if doing this will make it work as when LabVIEW was first installed. Also, I do not think that simply replacing your current ini file with the initial one would make it work. Unfortunately, I do not know if uninstalling and reinstalling VISA would go return it back to the initial state.

 

I would suggest asking specifically about this issue on a new post. It may be able to receive more relevant answers/attention and help other customers in the future should they run into the same questions. I’m sorry that I don’t have all the information you’re asking for readily available, but perhaps if you posted more about what you’re trying to do and why it’s important a workaround could be achieved.

 

Also, I will be out of the office next week, so hopefully another AE or customer can help you out. Thanks and have a good weekend!

 

Best,

Carisa

Applications Engineer
National Instruments
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Message 29 of 41
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Carisa,

 

Thank you for your help. I've gotten some good knowledgeable replies, including yours, but without a complete answer, so I'm not hopeful a new post would get results, but it's worth a try. I realize that VISA works with information that is in the registry as to which COM ports are installed and which are currently not connected or active. That's why I thought if I used a program such as Device Remover, and had some way to reinitialize VISA, such as uninstallilng, that might do the trick. This has been the basic theme of this post, which is why a new post might be redundant. But you never know who might see it.

 

Anyway, since I still may have your ear, can you ask other NI engineers?

 

(When our Production PC's have this problem again in a few months I can try some of these things before I do a system image restore. When that happens I can post the results.)

 

Ed

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