Can I send raw packets via WEB UI or Telnet? Emulate EM10?

[Mike-FUT]

Hi All,

I have a Buderus GB162 boiler which is connected to a EM10 module. The EM10 module is used for telling the boiler either the set value of the flow temperature (°C) or the set value of the burner power (%).

When I run "watch on" and connect 5 V to the EM10 this gives these values for the set flow temperature:
[emsesp] alert(0x12) -W-> boiler(0x08), UBASetPoints(0x1A), data: 32 (for setting it to 50 °C)
[emsesp] alert(0x12) -W-> boiler(0x08), UBASetPoints(0x1A), data: 00 (for setting it to off)

That looks exactly the same for the set burner power:
[emsesp] alert(0x12) -W-> boiler(0x08), UBASetPoints(0x1A), data: 32 (for setting it to 50 %)
[emsesp] alert(0x12) -W-> boiler(0x08), UBASetPoints(0x1A), data: 00 (for setting it to 0 %)

I thought there's no way that the boiler can understand if it is % or °C requested so I was checking the raw packets ("watch raw"):
[telegram] Rx: 12 08 1A 00 00 11 (for setting the set flow temperature to "off")
[telegram] Rx: 12 08 1A 01 00 13 (for setting the set burner power to "0 %")

So there is a different offset (as expected) but this is only shown when displaying raw bytes.

Many questions for this topic:

• Since EM10 is such an important device and basically THE buderus standard for controlling the heating with a home automation system is it possible to add this as simple commands to set the "set flow temperature °C" or "set burner power %" like it would be done with connecting a 0-10 V signal to EM10 so I can get rid of this old fashioned 0-10 V link?
• Since right now it can't be directly sent is there a way for me to send raw packets?
• If i send raw bytes do I have to calculate CRC or will EMS-ESP do that for me and attach it?
• Is it possible to show these rather important values somewhere?

Sorry guys if any of these questions are stupid but I'm brand new to EMS-ESP and I couldn't find any of these answered and also I couldn't find anything related to EM10 which surprised me since to my knowledge that's the official way of controlling the boiler from external systems.

[MichaelDvP]

The log shows the offset in brackets if offset is a positive value. The 1A telegram in offset 0: flowtemp, offset1: burnpower,
By writing to selflowtemp and selburnpow you can send the values to the boiler.
For sending raw commands there is the command system/send with a string as parameter without CRC, e.g. in terminal call system send "1B 08 1A 01 32" for setting burnpower to 50%. (mqtt-topic system/send, API-URL: http://ems-esp.local/api/system/send)

Writing these values is temporary, the boier resets to default setting after ~3 minutes. So you have to repeat the commands every minute. That is what EM10 or thermostats do. In the 3.6 beta we have a scheduler where you can define such values. Create scheduler value with timer 00:01 and command boiler/selburnpow, value 0 and choose a name, this can also be selburnpower, but must be unique in scheduler. Than you can write a new value to scheduler/selburnpower and this is sent to boiler every minute.

[Mike-FUT]

Amazing answer!
Thank you very much! When testing selflowtemp I selected a lower value than the current value so that means nothing will change when RC35 is sending a higher value at the same time.
But when using EM10 i select higher temperatures which then increases the "set flowtemp" so I thought selflowtemp doesn't work. I didn't recognize I was doing it all wrong...

So thank you again for bringing some light into the whole thing and how the EM10 works (sending every minute, I verified it already by watching "0x1A").