Troubleshooting

This page details some known peculiarities with QMI or its supported devices and ways of working around them.

Devices

USBTMC on Windows

Connecting with USBTMC devices on Windows can be tricky. Make sure you have libusb1 and pyvisa installed. https://pypi.org/project/libusb1/ and https://pypi.org/project/PyVISA/ (and perhaps pyvisa-py).

Then you’ll need to have the backend set-up correctly, in case the libusb-1.0.dll is not found in your path. An example script to set-up and test the backend is:

import usb.core
from usb.backend import libusb1

backend = libusb1.get_backend(
    find_library=lambda x: "<path_to_your_env>\\Lib\\site-packages\\usb1\\libusb-1.0.dll")

dev = list(usb.core.find(find_all=True))

If you can now find devices, the backend is set correctly. There are of course other ways to set-up your backend as well, but as said, it can be tricky…