USB->GPIB issue communicating with device. "VISA Find Resource"

[jeremyhannon]

I just had the same issue and wanted to add some notes on additional steps I had to take to get things working.

I've got an Agilent 82357B USB to GPIB converter, using it to read both a Rohde&Schwarz Signal Generator (SMU200A) and Spectrum Analyzer (FSQ), daisy-chained along a GPIB cable.  First of all, I forgot to make sure to change their GPIB addresses to different numbers (mine were both 20 by default and I couldn't talk to both on the same adapter).  Afterwards, I could see both in the Agilent IO Libraries 14.2 Connection Expert and send IDN? queries.  However, I couldn't see them in Measurement & Automation Explorer (MAX 4.2) or Labview (8.2.1).

Based on this post and KB article, I enabled Tulip which allows Labview to see Agilent devices (disabled by default for competitive reasons I assume).  Tools -> NI VISA -> NI VISA Options -> Passports -> Checkbox for "NiVisaTulip.dll".  That's where the other article stopped, though.  You have to Save the settings or close/reopen MAX.  Then, under "Devices and Interface" my GPIB devices appeared under "Miscellaneous VISA Resources".  Great!  I gave each GPIB device a "VISA alias" and saved everything.

Ok, but here's my problem ... I can't successfully initialize the instrument drivers. 

If I use use "VISA Find Resource" and search for "GPIB?*INSTR" with search mode 0 (return Canonical Names), I get no results.  If I use search mode 4 (Include All Aliases), I get all COM & LPT aliases for my computer, as well as the three VISA aliases I gave my GPIB devices.  However, I get error 1073807195 " The interface type is valid, but the specified interface number is not configured."  I believe this driver is looking for the Canonical VISA Resource Name (one of the purple boxes).

If I Create a Constant and manually type in either of my device names "GPIB0::8::INSTR" or "GPIB0::9::INSTR", that generates an error as well.

I also tried using VISA Open and manually typing in the GPIB device name, but that didn't work either.

Any suggestions?  Screenshot and .vi attached.

Jeremy

[Chris_R.]

Hi Jeremy,

That error usually means that the specified interface is not configured properly. Often it means that you are incorrectly addressing the VISA resource even though it is a valid resource. Are you able to see this instrument in your GPIB board's configuration utility? If so, make sure that any configuration here is the same as in LabVIEW. If you are able to open a test panel to the instrument and communicate with it outside of LabVIEW, chances are that it is not being properly addressed in LabVIEW.  Confirm this and post back what you find.

Have a great day!

[jeremyhannon]

Just had to setup USB -> GPIB control on another computer and returned to this article to get everything setup correctly.

1)  Enable Tulip in MAX

2)  Use MAX to identify the GPIB devices, ping them with an IDN? querry, and maybe give them VISA aliases (not required)

3)  Shut all MAX and Agilent Connection Expert windows

4)  My program finally worked correctly.  If along the way your program doesn't run, make sure there aren't other programs (MAX, Agilent IO) already controlling the GPIB resource.

Jeremy

P.S.  I attended a SE Wisconsin Users Group Meeting and heard about the new Reprogrammable IO DAQ boards with on-board FPGAs.  Good idea and I like the idea of converting LabVIEW code into VHDL.  Please make the output VHDL viewable/readable in the future and it might become a useful development tool.

[Chris_R.]

Hi Jeremy,

Thanks for the update of your progress and yes, the intellegent DAQ boards are quite impressive.  Click here for more details if needed.

Have a great day!

[TChi]

Thank you, jeremyhannon for your solution.

I've been looking for this. 

Have a nice day!