How can i have a closer look into the log files?
There a a couple of different ways to have a look into the logs. Just try to use
less /var/log/fabscanpi/fabscanpi.log
or
cat /var/log/fabscanpi/fabscanpi.log
or
more /var/log/fabscanpi/fabscanpi.log
to list the content of the log file.