Operating system name and version: Raspbian GNU/Linux 9 (stretch)
Version of smsd: Version 3.1.15
Smsd installed from: package repository
Name and model of a modem / phone: Huawei E3531
Interface: USB

I receive sms messages in binary format and want to process them (forward to a webserver by http-request). Unfortunately the binary data in the file in /var/spool/sms/incoming seems to have a wrong charset, so it's not possible for me to forward that data. But the hexadecimal text in the logfile is correct. Is it possible to process the user data in hexadecimal format?

Found a solution by myself. I use ussd_convert = 4 in the config. Now I can proceed with the received data.