viWrite working, VISA write return's BFFF0011 insufficient location information, why?

[BarnaCsenteri]

I have issues with a VISA device which works from NI-MAX test panel but it doesn't with Labview VISA write.

I did checked NI I/O Trace to see the difference and the buffer for "*IDN?\n" is the same, the difference is that NI-MAX Visa test panel uses viWrite while the Labview visa write uses "Visa write". In theory it should not be any difference between the two but it seems it does.

Here it is the trace, the upper one when I try from NI-MAX, the two errors are when trying from Labview. I did tried with shortened VISA reference and also direct TCPIP link (both returns the same error). The VISA Open works however (added a probe after visa open and the result is at the end of the screenshot so it seems it finds it ok, the issue appears with first VISA write which is a IDN query.

I am aware of this two issues:
https://forums.ni.com/t5/LabVIEW/IDN-works-in-VISA-test-panel-but-VI-does-not/td-p/3575540/page/2

https://forums.ni.com/t5/LabVIEW/VISA-Hex-0xBFFF0011-Insufficient-location-information-or-the/td-p/6...

however I do not have any additional driver, nor package I can install (except different versions of NI-VISA).

My labview version is 2019sp2 and NI-VISA is 21.5 (installed with NI-DAQmx). 

[l.hovs]

Hello BarnaCsenteri,

Did you check this article before? Follow the link to solve the error, there is quite well described about this error solution. 

Regards) 

________

Best way to thank is giving Kudos/Marking as a solution

[BarnaCsenteri · Accepted solution]

That link most probably comes from my support request since I recognize the text 🙂 And did not solve my issue. 
Also configuration errors does not give "intermittent" errors but they rather always give error - never the less it was not my case.

I found a workaround meantime but I think it is a VISA bug behind or a bug in the VXI-11 service ...

The difference is between visa async and sync and also if a device is setup as "manual entry of a raw socket" vs. "auto detect of a lan instrument" from NI-MAX.

For whatever reason async mode combined with "auto detect" resulted in intermittent errors (with VISA test panel working both case). What I do think is that VISA serial write and read does some kind of VXI-11 call if autodetect LAN device is used and that one fails.

Raw socket always works (sync and async) so I simply dumped autodetect from my setup - I'll had problems with autodetect before too so probably I'll never use it again.