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~! > > > This e-mail and any attachments may contain confidential and > privileged information. If you are not the intended recipient, > please notify the sender immediately by return e-mail, delete this > e-mail and destroy any copies. Any dissemination or use of this > information by a person other than the intended recipient is > unauthorized and may be illegal. > >