Best temperature format for KNX climate?

Configuration
1

Hi.
I am in the process of installing my KNX. I am currently working with the MDT AKH-0800.03 heating actuator and the MDT SCN-RTN55S.01 room temperature extension. Both support the following temperature change formats:

  • 1.007 DPT_Step
  • 6.010 DPT_Value_1_Count
  • 9.002 DPT_Value_Tempd
  • 9.001 DPT_Value_Temp

Now I’m wondering which format should I choose? Are there any advantages/disadvantages, especially from the point of view that it should be integrated with HomeKit?
Thanks.

2

Hi :wave:!
The first (1bit) is not supported. The others should be fine.
HoneKit uses the HA entity as mid-layer to Knx so it doesn’t matter for that.

3

Hello Matthias,
thanks for your reply.
I was wondering if large temperature changes matter?
Because it could be that this change cannot be implemented with 1 step.
Then an absolute value would be the better choice…
If there are no limitations of HA, are there any other considerations as to which format to choose?
Thx

4

If you have other devices that only support one of the other 2 use that.
Other than that Shift-DPT 9 is more straightforward as it directly encodes temperst shift, Shift-DPT 6 needs a Multiplikator - mostly 0,1 and has 1byte smaller payload (which doesn’t really matter).
Sending the temperature directly, without a shift value would be my personal preference as it is the simplest and I don’t use different modes (other than frost protection which I don’t want to change value for).