On (re)connect, the manual-mode controls (heater power/activate, temp
soll, heatrate soll, stirrer speed/activate) sync themselves once to
the server's current value via setValue()/setCheckState(). Without
blockSignals(), that programmatic update also fires valueChanged/
stateChanged, echoing the value straight back as a command.
For the heater power slider this was the cause of the "stale power >
0 after restart" bug: if the slider happened to sync to a nonzero
power (e.g. reconnecting mid-heat), the echoed {'Power': ...} set
tasks/heater.py's power_soll, which power_soll = max(power_soll,
power_actor) then latches as a floor that never drops back down on
its own - the heater would then stay at least that hot regardless of
what the actual controller/Sud wanted afterwards.
jens
b51d802b31