LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

ENET/100 visa session hang?

Labview Development 2009

NI 488.2 version 3.1.2

Windows XP and 7

 

Hello,

I have been troubleshooting this annoyance for several weeks.  I have a Labview application that allows users to change VISA sessions to connect to GPIB instruments at 5 identical ENET/100 boxes at remote locations worldwide.  Works great except at one site, where connections may be made/ended randomly for minutes, hours, even days until it mysteriously hangs at the VISA Open VI.  No error messages, no warning, no rhyme or reason.  Setup is identical at all 5 locations, but only this one has a issue. Occasionally I will see a "Resetting VI: (name)" message upon termination, but not always.  I am closing VISA sessions whenever a session connection change is made. 

 

To reduce complexity for troubleshooting I created a small VI (see partial snippet) that uses the same VISA session list, opens the selection, gets an ID from the attached GPIB instrument, then closes the session.  Same issue at this one site.  If I exit Labview completely, then restart, I can again successfully use the VISA resource per above.  Occasionally an "Insufficient system resources...etc" error message will be generated.  Also, and this is what is killing me, I can still access the site's GPIB instrument through MAX even though the VISA session is hung.

 

I've tried searching for solutions on NI and googling without success.  Anyone have a clue?

0 Kudos
Message 1 of 3
(2,721 Views)

Does there seem to be any consistency about when this error happens, or has it just appeared at completely random times until now?

 

Is the software setup in all of this systems identical, I can see that some of them are running Windows 7 and others XP, could it be that the problematic one is getting updates at some points, resulting in this problem?

 

You mention that this are in remote locations worldwide, so I take it there's little opportunity to verify on the actual physical setup, is this correct?

0 Kudos
Message 2 of 3
(2,673 Views)

Thanks for the response.  Hangs appear to be random, with no consistency I can determine.  Occurs in runtime version being used on an XP box and also in the development environment running on an Windows 7 box.

The ENET/100 boxes were identically set up on site then shipped to other locations, but can still access setup via MAX over an ethernet connection.  Therefore I have tried, for example, increasing the I/O timeout parameter from a default of 10s to 30s (unsuccessful, no effect).

I suppose a more pertinent inquiry is why are there no error messages being generated when a VISA session hangs?  I would think a timeout error or such would be standard protocol.  And I can't seem to come up with a way to recover the hung VISA session programatically which also seems odd, the only way is to bring the VI down competely;  in the case of the runtime exiting the exe and in the case of the development environment exiting Labview entirely including Help and Getting Started windows. 

And it appears the the runtime can still have its VISA session accessible even though the development case is hung and vice versa.  And of course MAX sessions are unaffected by either.  So the remote ENET box setup and GPIB bus are still functioning, just the local VISA session somehow screws up but I can't seem to put my finger on it.

0 Kudos
Message 3 of 3
(2,668 Views)