Yes, switch is on pos 1 (low) on the perilex

Still a question for control the fan speed:

Send: x07 xF0 x00 x99 x01 x04 x4B x07 x0f
Receive: Nothing. Also no action

What is wrong in this command?

@Sappien, Thanks for your reply. I have tested it again, where I calculated the checksum with Excel file. Several commands are working, but several not. I still do not understand what was wrong with previous testing. But now I get more response than before. I expect that for the commands that are ...

Hello, I do have simular communication issues. As I am not tha familiar with phyton/domotics, I have tried communication with USB/Serial converter. I used RealTerm to communicate with the WHR930. When I select the example from "Protokollbeschreibung_ComfoAir" (0x07 0xF0 0x00 0x69 0x00 0x16 0x07 0x0F ...