Altherma 4: the first survey of a real unit (@herbert131, #523) reads the tank temperature where every R32 unit has it: the line is back in the definition, the drawing's tank gets a value (it is the tank's lower sensor, a few degrees under the display's). The targets (hot water, leaving water, room) are not on this port and read 0: a setpoint of exactly 0 is now left out instead of "Target 0°".
Two-zone ECH2O units: the mixed zone's water came from a register the ECH2O units never serve (248 °C on an EBSXB16P50DF, @dc6jn in #599). It is the bizone kit's "[EKMIK] Bizone kit mixed leaving water temperature R1T" on them, now preferred wherever it reads something, on the page, in the two-zone detection and in the defaults. Their room temperature and target are the RoCon controller's, the Daikin board's read a constant 20.0: no longer in the recommended selection of the ECH2O definitions (tick them back if yours read right).
Values: "Pump pwm fdbk" and the two other enumerated states that share their byte with flags ("RT Control State", "Tank state") now read the state alone, not the whole byte (@Rondal, #621). The Altherma HT hydrobox definitions declare their R134a under code 805 (804 is R744 in the reference table). Operation mode 201 lists "Auto Heat" before "Auto Cool", the opposite of 217.
No backup heater (EDLA…W1/V3 monoblocs): the after-heater sensor (R2T) reads exactly 0 there, so the leaving water falls back to the heat exchanger's (R1T) on the drawing and in the delta T (@Senaxx, #599; the card had it since 1.0.20).
Fixes: no more false watchdog restart when the loop beats between the watchdog's two reads (@forTT78, #620, a few per week on an Atom Lite). The echo of our own query through some level shifters is dropped (#585). No water pressure in the ECH2O defaults, the port reads 0 there (#615).
Experimental, off by default: power limit. Settings → Experimental → "Power limit…" caps the heat pump's power (kW) or current (A) through the port, as the installer's demand-control input does, with a number and a switch in Home Assistant and on the web page. Tried on my unit only (16 kW EAVH/EAVX D); the other boards follow once their addresses are mapped, it says "not available" elsewhere. Details in doc/control.md.
Home Assistant card v1.0.21: the mixed zone from the bizone kit's sensor, a setpoint of 0 left out.