12-18-2006 05:54 PM
12-19-2006 04:34 PM
I am not familiar with PyVISA or that distribution of Linux, but I did notice a couple things that we can try. First, "GPIB:00:INSTR" is not a valid resource descriptor for NI-VISA, and other VISA's as well. Typically, the format is GPIB0::2::INSTR, where "2" is the address of the instrument and "GPIB0" is the GPIB card 1. Unless PyVISA is converting this format, then this may be the problem.
Also, in blue, you have "GPIB0::00::INSTR". This is more like what format VISA requires, but an instrument with a primary address of 0 typically does not exist since most of the time, the controller has an address of 0. You may want to check your instrument to see what the address is and change it if the controller has the same address.
I hope this helps, but let me know if you have any other questions!
12-20-2006 01:34 PM
12-21-2006 12:30 PM
Is the GPIB-USB-HS recognized by the computer? Also, are you sure this instrument is in working order? Has this setup worked before on this computer?
12-21-2006 12:44 PM
12-21-2006 12:57 PM
12-21-2006 01:23 PM
12-21-2006 02:06 PM
Have you installed NI-VISA successfully? Since the PyVISA package doesn't have the low-level VISA commands, you will need to install a full version of VISA if you haven't already. Since you have purchased a GPIB-USB-HS, you do not have to purchase it separately. You can download it here if you need it. Ubuntu is not a supported distribution for NI drivers, so it may not install properly on your system.
I hope this helps! I am sorry for my limited resources for you, but will send you what I can even though National Instruments does not support PyVISA or Ubuntu.
Have a great day!
04-07-2010 06:56 PM
I am using Windows XP and have installed NI-VISA. Iam using pyvisa.I have 2 GPIB equipments. CMU200 and SMU200. The SMU 200 doesnt have a secondary address. But the CMU200 has around 8to 10 secondary address.when using
equip=visa.instrument(GPIB::28) ----works normally. (28 is the primary address of the SMU200)
but when using
equip=visa.instrument(GPIB::13) ---- doesn't work. throws the following exception.
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "c:\python26\lib\site-packages\pyvisa\visa.py", line 290, in instrument
return GpibInstrument(resource_name, **keyw)
File "c:\python26\lib\site-packages\pyvisa\visa.py", line 594, in __init__
Instrument.__init__(self, resource_name, **keyw)
File "c:\python26\lib\site-packages\pyvisa\visa.py", line 358, in __init__
File "c:\python26\lib\site-packages\pyvisa\visa.py", line 152, in __init__
File "c:\python26\lib\site-packages\pyvisa\vpp43.py", line 557, in clear
File "c:\python26\lib\site-packages\pyvisa\vpp43.py", line 398, in check_status
raise visa_exceptions.VisaIOError, status
pyvisa.visa_exceptions.VisaIOError: VI_ERROR_NLISTENERS: No listeners condition
is detected (both NRFD and NDAC are deasserted).
I believe I need to specify the secondary address also.. But i don know how to do that in pyvisa. Or if its something else kindly guide me through this .
04-08-2010 02:19 PM
I actually figured it out. The format for specifying the secondary address is the same as i had mentioned.
equip=visa.instrument("GPIB::13::98") with primary add-13 and sec add-98 provided the secondary address is specified on the instrument connected. If the secondary address is not specified, then the default sec add is 0 so we need to specify it like