[MOSAIC] - Therrmostat - KNX compliance

[Monolithos]

Hello,

Since the last update of mosaic (FW 20170620), I find it suits a lot of basic visualisation needs so I tend to use it more and more

But (ain't there always...), I'm currently doing a mosaic visualisation using also the Mosaic thermostat widgets and found it has 1) a bug and 2) it is not completely KNX HVAC mode compliant.

1) the bug : when receiving the status object for KNX HVAC mode (as a 1 byte object DPT 05) 3 (Night reduction) or 4 (Builing protection), the script behind the widget apparently distracts 1 from the value and shows the wrong icon on the mosaic thermostat (Building protection shows as Night reduction and Night reduction shows as Standby (Eco) mode.
No object values are changed and no bus traffic, just an internal visualisation error but of course confusing for the user.

2) Best practices for KNX HVAC mode (via dpt 20.102) implementation is to use an offset of the basic comfort setpoint temperature to define Standby and Night reduction modes.
Also, an offset is to be used to alter the comfort setpoint temperature.
The mosaic widget only supports the  changing (and visualisation) of a 2 byte object while the KNX HVAC offset is a 1 bit signed object (dpt 06.010).
As a result, in order to change the setpoint temperature, you now need to change the basic comfort setpoint temperature, involuntarily also changing the values for Standby and Night Reduction.


It would be very nice if the thermostat would support the complete KNX HVAC mode scenario



Kind regards,
Hendrik

[Daniel]

Hello,

Since the last update of mosaic (FW 20170620), I find it suits a lot of basic visualisation needs so I tend to use it more and more

But (ain't there always...), I'm currently doing a mosaic visualisation using also the Mosaic thermostat widgets and found it has 1) a bug and 2) it is not completely KNX HVAC mode compliant.

1) the bug : when receiving the status object for KNX HVAC mode (as a 1 byte object DPT 05) 3 (Night reduction) or 4 (Builing protection), the script behind the widget apparently distracts 1 from the value and shows the wrong icon on the mosaic thermostat (Building protection shows as Night reduction and Night reduction shows as Standby (Eco) mode.
No object values are changed and no bus traffic, just an internal visualisation error but of course confusing for the user.

2) Best practices for KNX HVAC mode (via dpt 20.102) implementation is to use an offset of the basic comfort setpoint temperature to define Standby and Night reduction modes.
Also, an offset is to be used to alter the comfort setpoint temperature.
The mosaic widget only supports the  changing (and visualisation) of a 2 byte object while the KNX HVAC offset is a 1 bit signed object (dpt 06.010).
As a result, in order to change the setpoint temperature, you now need to change the basic comfort setpoint temperature, involuntarily also changing the values for Standby and Night Reduction.


It would be very nice if the thermostat would support the complete KNX HVAC mode scenario



Kind regards,
Hendrik

Hi Hendrik

The thermostat widget was developed by our SE friends. It was designed purely for those  thermostat.  It is bit tricky with the heating modes.  'Operation mode input' is 1 byte object where:
1 - Comfort,
2- Standby,
3- Night,
4 Frost
This is to change the mode.
To make it works correctly you also need 'Thermostat status, alert' object which is 1 byte status from SE thermostat but this time encoding is different and is bit by bit:
Bit 0 - Comfort (1/0)
Bit 1 - Standby (1/0)
Bit 2 - Night operation (1/0)
Bit 3 - Frost/heat protection (1/0)
Bit 4 - Dewpoint alarm 1/0
Bit 5 - Heating (1)/cooling (0)
Bit 6 - Controller inactive (1/0)
Bit 7 - Frost alarm (1/0)


All this info is taken in to account in the widget. For example when heating is on then temperature will become red and blue when cooling. 
You can read about this object here page 41.

If your Thermostat support such object then you can use it.
As I mentioned this is special widget made by SE for those devices.

BR