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rm.list_resources() Error -- No handlers could be found for logger "pyvisa-py.usb"

See original GitHub issue

Hello. I have been messing around with PyVisa-py for a little bit, and although I’ve got it working on my Mac, I cannot seem to get it working on my Linux machine…

I’m currently running Linux with kernel: 4.15.0-33-generic and have installed both pyvisa and pyvisa-py through pip using the instructions shown here: http://python-in-the-lab.blogspot.com/2014/10/communicating-with-instruments-using.html

However, I get the following error when trying to use the list_resources() function:

Python 2.7.12 (default, Dec  4 2017, 14:50:18) 
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import visa
>>> rm = visa.ResourceManager('@py')
>>> rm.list_resources()
No handlers could be found for logger "pyvisa-py.usb"
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!
libgpib: error locking board mutex!

And I have the following PyVisa info:

Machine Details:
   Platform ID:    Linux-4.15.0-33-generic-x86_64-with-Ubuntu-16.04-xenial
   Processor:      x86_64

Python:
   Implementation: CPython
   Executable:     /usr/bin/python
   Version:        2.7.12
   Compiler:       GCC 5.4.0 20160609
   Bits:           64bit
   Build:          Dec  4 2017 14:50:18 (#default)
   Unicode:        UCS4

PyVISA Version: 1.9.1

Backends:
   ni:
      Version: 1.9.1 (bundled with PyVISA)
      Binary library: Not found
   py:
      Version: 0.3.0
      ASRL INSTR:
         Please install PySerial (>=3.0) to use this resource type.
         No module named serial
      TCPIP INSTR: Available 
      USB RAW: Available via PyUSB (1.0.2). Backend: libusb1
      USB INSTR: Available via PyUSB (1.0.2). Backend: libusb1
      GPIB INSTR: Available via Linux GPIB (4.1.0)
      TCPIP SOCKET: Available

Any help would be greatly appreciated!

Issue Analytics

State:
Created 5 years ago
Comments:13 (6 by maintainers)

Top GitHub Comments

1reaction

bdlabittcommented, Mar 25, 2019

GitHub code tags, they are the <> on the grey bar in the “Write” tab. My code had carriage returns in it but GitHub rendered it as continuous lines. Also my python code Out[4] should have been rendered on the next line. Makes it hard to clearly convey ideas or comments, if GitHub rearranges things.

Not pyvisa-py’s problem.

It wasn’t clear to me initially, that I had to install both PyUSB and libusb1.
Perhaps you should just add a line (for linux installs) that states one may have to modify udev rules to allow non-root access? http://ask.xmodulo.com/change-usb-device-permission-linux.html has instructions for this.

0reactions

slina0commented, Feb 2, 2020

Hi bdlabitt, where did you add the two lines to? to “/etc/udev/rules.d/”?

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