Hi @captaindork sorry for delay,.... the position of the damper (which is the bypass) is indicated through a single bit of the multi purpose IO-Port 2. The library defines that as property 38 DamperMotorPositionProperty. In the mysensors example it is published as const uint8_t DAMPER_MOTOR_POSITION = 42; The value is either 1 or 0. I mapped it in FHEM as follows attr MYSENSOR_Vallox mapReading_DamperMotorPosition 42 value1 define MYSENSOR_Vallox_DamperMotorPosition dummy attr MYSENSOR_Vallox_DamperMotorPosition alias WRG-Bypass attr MYSENSOR_Vallox_DamperMotorPosition devStateIcon 1:rc_GREEN 0:rc_BLANK attr MYSENSOR_Vallox_DamperMotorPosition event-on-update-reading state attr MYSENSOR_Vallox_DamperMotorPosition group Status attr MYSENSOR_Vallox_DamperMotorPosition icon vent_bypass attr MYSENSOR_Vallox_DamperMotorPosition room Lüftung attr MYSENSOR_Vallox_DamperMotorPosition sortby 3 define MYSENSOR_Vallox_DamperMotorPosition_Notify notify MYSENSOR_Vallox:DamperMotorPosition:.* { my $d = sprintf ("%.0f", ReadingsVal("MYSENSOR_Vallox","DamperMotorPosition", 0));; fhem("set MYSENSOR_Vallox_DamperMotorPosition $d");;} define MYSENSOR_Vallox_DamperMotorPosition_Notify2 at +*00:01:00 { my $d = sprintf "%.0f", ReadingsVal("MYSENSOR_Vallox","DamperMotorPosition", 0);; fhem("set MYSENSOR_Vallox_DamperMotorPosition $d");;}