USB device permission

[Dan Marlow]

Hello,

I have installed the uldaq S/W according to the published instructions (e.g., (https://linuxize.com/post/how-to-install-gcc-compiler-on-ubuntu-18-04/ ) and https://www.mccdaq.com/PDFs/Manuals/UL-Linux/python/overview.html ).    Everything seems fine in that the a_in.py test program runs and finds the device I am using.    However, it gives a permission error that I am unable to resolve.   The output looks like:

 

marlow@phy-gr10a:~/test$ python3 ./uldaq-1.2.3/examples/a_in.py
Found 1 DAQ device(s):
  [0] USB-1208FS-Plus (NO PERMISSION)
libusb_open() failed: LIBUSB_ERROR_ACCESS
Please select a DAQ device, enter a number between 0 and 0: 0

Connecting to USB-1208FS-Plus - please wait...
Traceback (most recent call last):
  File "/home/marlow/test/./uldaq-1.2.3/examples/a_in.py", line 146, in <module>
    main()
  File "/home/marlow/test/./uldaq-1.2.3/examples/a_in.py", line 76, in main
    daq_device.connect(connection_code=0)
  File "/home/marlow/.local/lib/python3.10/site-packages/uldaq/daq_device.py", line 136, in connect
    raise ULException(err)
uldaq.ul_exception.ULException: ULError.USB_DEV_NO_PERMISSION: Insufficient permission to access this device

 

Is there a way on Linux (Ubuntu) that I can tell which device is being used so that I can change its permission?

 

Dan Marlow

 

 

 

 

 

[JRys]

Hello Dan,

If you log in as the root administrator, will the example run without errors? 

Best regards,
John

[Charlie2134]

On 6/16/2023 at 3:13 PM, Dan Marlow said:

Hello,

I have installed the uldaq S/W according to the published instructions (e.g., (https://linuxize.com/post/how-to-install-gcc-compiler-on-ubuntu-18-04/ ) and https://www.mccdaq.com/PDFs/Manuals/UL-Linux/python/overview.html ).    Everything seems fine in that the a_in.py test program runs and finds the device I am using.    However, it gives a permission error that I am unable to resolve.   The output looks like:

 

marlow@phy-gr10a:~/test$ python3 ./uldaq-1.2.3/examples/a_in.py
Found 1 DAQ device(s):
  [0] USB-1208FS-Plus (NO PERMISSION)
libusb_open() failed: LIBUSB_ERROR_ACCESS
Please select a DAQ device, enter a number between 0 and 0: 0

Connecting to USB-1208FS-Plus - please wait...
Traceback (most recent call last):
  File "/home/marlow/test/./uldaq-1.2.3/examples/a_in.py", line 146, in <module>
    main()
  File "/home/marlow/test/./uldaq-1.2.3/examples/a_in.py", line 76, in main
    daq_device.connect(connection_code=0)
  File "/home/marlow/.local/lib/python3.10/site-packages/uldaq/daq_device.py", line 136, in connect
    raise ULException(err)
uldaq.ul_exception.ULException: ULError.USB_DEV_NO_PERMISSION: Insufficient permission to access this device

 

Is there a way on Linux (Ubuntu) that I can tell which device is being used so that I can change its permission?

 

Dan Marlow

 

 

 

 

 

hi, i have encountered the same issue. I am using a linux workstation with the newest Ubuntu distribution. 

[Fausto]

@Dan Marlow and @Charlie2134,

On 6/20/2023 at 8:42 AM, JRys said:

If you log in as the root administrator, will the example run without errors? 

 

@Charlie2134,

Are you using the USB-1208FS-Plus?

Which version of Python are you using?

Have you tried searching online for "libusb_open() failed: LIBUSB_ERROR_ACCESS"?

Here's one hit:  https://stackoverflow.com/questions/72616674/error-libusb-open-failed-with-libusb-error-access-visual-studio-code

 

Regards,

Fausto

[Charlie2134]

On 8/4/2023 at 1:36 PM, Fausto said:

@Dan Marlow and @Charlie2134,

 

@Charlie2134,

Are you using the USB-1208FS-Plus?

Which version of Python are you using?

Have you tried searching online for "libusb_open() failed: LIBUSB_ERROR_ACCESS"?

Here's one hit:  https://stackoverflow.com/questions/72616674/error-libusb-open-failed-with-libusb-error-access-visual-studio-code

 

Regards,

Fausto

Hello Fausto,

Thank you very much for your response. I resolved the issue.