I installed NI-488.2 GPIB driver in my Scientific Linux 5.5, and now it is
working~! Thanks very much Mathew!

PS: just curious: is there any alternative solution without having NI
firmware involved?

On Tue, May 24, 2011 at 3:56 AM, Mathew Maher <[log in to unmask]> wrote:

> If you're using NI-VISA then you probably need NI-488.2 GPIB driver, not
> linux-gpib. Beware, however, NI-488.2 GPIB drivers do not work on Linux
> with USB adapters - you'll need a PCI GPIB card.
>
> Mat.
>
> Mathew Maher
> Simulation Team Leader
> Surrey Satellite Technology Ltd
>
>
> ________________________________
>
> From: [log in to unmask]
> [mailto:[log in to unmask]] On Behalf Of
> eigenroot
> Sent: 24 May 2011 00:25
> To: [log in to unmask]
> Subject: Errors of instrument control with PyVISA in Scientific Linux
> 5.5
>
>
> Hello everyone,
>
> I would like to control a Keithley source meter with PyVISA in the lab.
> The operating system is Scientific Linux 5.5, and the Python version is
> 2.4. I first installed NI-VISA's Linux package
> (http://joule.ni.com/nidu/cds/view/p/id/2040/lang/en) which was
> compatible with Scientific Linux 5, and then ctypes from
> http://python.net/crew/theller/ctypes/ and linux-gpib from
> http://linux-gpib.sourceforge.net/. After everything was done
> successfully I fired up an interactive Python session, and typed
>
> import visa
>
> No errors. And then I typed
>
> keithley = visa.instrument("GPIB::25")
>
> but got errors:
>
> Traceback (most recent call last):
>  File "<stdin>", line 1, in ?
>  File "/usr/lib/python2.4/site-packages/pyvisa/visa.py", line 287, in
> instrument
>    interface_type, _ = \
>  File "/usr/lib/python2.4/site-packages/pyvisa/vpp43.py", line 777, in
> parse_resource
>    byref(interface_board_number))
>  File "/usr/lib/python2.4/site-packages/pyvisa/vpp43.py", line 398, in
> check_status
>    raise visa_exceptions.VisaIOError, status
> pyvisa.visa_exceptions.VisaIOError: VI_ERROR_LIBRARY_NFOUND: A code
> library required by VISA could not be located or loaded.
>
>
> Could anyone please help? Thanks very much~!
>
>
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