fixed regression: reintroducing commit eudaq/eudaq@8ba4d96e55a4877792d90bde73ab7ccc2c519c4b "Added support for setting and calibrating PMT control voltages on TLU " by James Botte that was (unintentionally) overwritten by eudaq/eudaq@93c776b6fe2965746a9b2826051816e176931564