Later FW versions have USB enabled. Instead of previously catching SFP and modem logs via debug, and aux UART that requires 2 connections, this can be done from the one USB connection that exposes 4 ports within Windows.
Note that no special Windows driver need be installed.
- if AT+QCFGEXT=”debug” ==1 // Check debug setting is enabled first,
then AT+QCFGEXT=”debug”,0 // If it was enabled, then disable and reboot. - AT+QCFG=”usb”,1 // Enable the USB, then reboot.
After the reboot, 4 COM ports shall appear in windows device manager

4. The mapping of the ports are as follows:


6. Open 2 instances of the QSerialLog tool (921600 baud) in Windows, one for each serial log to capture the binary log data to log files.
Once you have this setup, then power-on, start the log capture, soft-restart the module
AT+CFUN=0
AT+CFUN=1
then capture the issue. Once captured then send back to Quectel FAE for analysis.
Note: Under Windows, the QSerialLog saves the files with Hidden attribute, so enable the view of hidden files in your File Explorer.
Credit: Miloje Zecevic