Backend:
Log files/diagnostics can be retrieved from the backend remotely, if the backend is capable of this.
Note: OCPP logs are different than the charger logs.
Web user interface:
Starting from 5.xx version it is possible to retrieve the log files via Web UI.
Web user interface 2.0
1. Connect laptop to the controller
2. Open Diagnostics page
3. Download Diagnostics
Legacy user interface (Web UI 1.0)
1. Connect laptop to the controller (Login as operator)
2. On operator page Download logs (next to log level)
3. If you downloaded the logs from master side, now repeat the same for the slave side
USB-stick:
Follow the instructions on this page