Help on "ebusctl grab result decode"

[Oliver-H1]

Hi,
I'm trying to decode some of the unknown messages sent within my system and could use hints.

Basically, when giving the above mentioned command (ebusctl grab result decode), my system spits out a huge amount of information which drowns me in unnecessary data, and hides the essential stuff. But at the same time the mentioned "decode" feature seems to be quite useful.

Let me give you an example:
when giving "ebusctl grab result all |grep f108b50905540200" i get a list with entries like the following:
f108b50905540200f80a / 050201f80a2d = 126
f108b50905540200fa0a / 050201fa0a2c = 122
f108b50905540200ff0a / 060201ff0ad0f9 = 127
f108b509055402005b0d / 0802015b0d0000c040 = 7959: hmux0 RunDataElectricPowerConsumption
f108b50905540200de08 / 080201de0800005341 = 1242: hmux0 RunDataAirInletTemp
...
From this it's pretty obvious that the essential part of the request is only in the last 2 bytes per message sent by the master. For the last 2 messages, there are entries in the .csv file, for the other 3 there are none.
There is also some structure in the answers from the slave:

• first byte is the length
• next 4 bytes repeat the command part of the request with a single bit changed to 1 (e.g. for the last example: 0201de08)
• remaining bytes are likely the relevant information

Thus, i would need a possibility to narrow down the build-in "decode" function to the relevant parts of the messages. And ideally provide single raw messages, as delivered by "ebusctl grab result" as input.
in the example above:
input: f108b50905540200f80a / 050201f80a2d plus some direction that the decoding should focus on "2d"
output: all possible decoding variants of "2d" based upon the pre-defined data types in ebusd.

Does anybody have an idea how to get that?

[chrizzzp]

Interesting message finds. Although, I don't think the feature you want is implemented (yet). To identify the message content you need to track them and make sense out of the (hopefully) changing values.

You can use the 'decode' command with the slave reply and a given datatype and script this to get the values e.g. for the most likely datatypes, e.g.

ebusctl decode uch 2d
45
ebusctl decode d1b 2d
45

ebusctl decode uin d0f9
63952
ebusctl decode sin d0f9
-1584
ebusctl decode d2c d0f9
-99.00
...

Still tedious... but not all datatypes are actually used. Most common ones are uch/d1b (1-byte) and uin/sin/d2c (2-byte)

or combine reading and decoding in one line:

ebusctl decode uch $(ebusctl hex 08b50905540200fa0a | tail -c 4)
ebusctl decode uch $(ebusctl hex 08b50905540200f80a | tail -c 4)
ebusctl decode d2c $(ebusctl hex 08b50905540200ff0a | tail -c 6)

This will decode only the last byte (tail -c 4) or the two last bytes (tail -c 6) of the slave reply, respectively.

[Oliver-H1]

Right. Good idea. I should have thought about scripting the stuff myself.
I have a recent model Vaillant heat pump and the existing csv don't cover all of the message types flying around (and I'm also interested in getting the data from all of the sensors installed in the machine - which are not fully covered yet).
But analyzing the unknown messages will be quite some work. After ~24h of operation I'm getting 160 lines of unknown message types from "ebusctl grab result" ...
Will share more insights, in case i get some.

[chrizzzp]

Please feel free to share the unknown messages! They could be interesting for older units, too. The three unknown messages above can be read on my older (split) system, too. Values are constant though it seems.

[Miq1]

Another victim here - aroTherm VWL 125/6 with quite some undecoded messages. Another thing related to ebusd seems to be values known and retrievable by ebusctl that are not polled by ebusd.

[Oliver-H1]

Please feel free to share the unknown messages! They could be interesting for older units, too. The three unknown messages above can be read on my older (split) system, too. Values are constant though it seems.

Hi,
thanks for the offer. The output of messages is quite lengthy. I'm not that experienced on github. How do i put this here? just pasted as plan text or as file attachment?
I have a "Split Plus" pretty recent model. But there might be a lot of similarities with the older "Split".
In the mean time, I've come a bit further with reading and experimenting summary is in another discussion

p.s.: some example messages:
1008b507020900 / 028305 = 30
1008b512020000 / 00 = 6
1008b512020064 / 00 = 2
1008b5120204ff / 00 = 7
1008b513020528 / 0101 = 7
f108b503020002 / 0affffffffffffffffffff = 28
f108b503020004 / 0affffffffffffffffffff = 26
f108b503020005 / 0affffffffffffffffffff = 31
f115b503020002 / 0affffffffffffffffffff = 26
f115b531020301 / 0101 = 6
f176b511021801 / 09000000000000000000 = 1
f176b511021802 / 09000000000000000000 = 1
f176b511021803 / 0101 = 1
1076b512030f0001 / 073202008b0110ff = 142
1076b512030f0202 / 072a0200520211ff = 29
1008b51009000000ffffff070000 / 0101 = 138
1008b510090003ffff68ff070001 / 0101 = 29
1076b51009000000ffffff010000 / 0101 = 173
f108b50905540200040b / 060201040bd0f9 = 1
f108b50905540200d90b / 080201d90b00000000 = 1
f108b50905540200da0b / 080201da0b00000000 = 1
f108b50905540200de12 / 060201de129001 = 1
f108b50905540200f40a / 050201f40a0a = 1
f108b50905540200f60a / 050201f60a0a = 1
f108b50905540200f709 / 050201f70901 = 1
f108b50905540200f80a / 050201f80a2b = 1
f108b50905540200ff0a / 060201ff0ad0f9 = 1
f115b52406020000000700 / 050300070000 = 25
f115b52406020003000100 / 06030301000000 = 14
f176b50905540200850b / 060201850bd494 = 1
f176b509055402008813 / 0e020188136400ffffffffffffffff = 1
f176b509055402008b13 / 0e02018b13ffffffffffffffffffff = 2
f176b50905540200db10 / 060201db108301 = 1

[chrizzzp]

Thank you.
With a few messages I can help, others are from registers I've never seen before:

messages from the HMU:
f108b50905540200d90b - running hours of compressor fan 2 (if system has two fans)
f108b50905540200da0b - number of starts of compressor fan 2 (if system has two fans)

Here are the lines from the CSV:

*r,,,,,,B509,540200,,,IGN:4,,,,,,,,,,,,,,,,,,,,,
r,,RunStatsFan2Hours,,,,,D90B,,,UIN;IGN:2,,hours,,,,,,,,,,,,,,,,,,,
r,,RunStatsFan2Starts,,,,,DA0B,,,cntstarts2;IGN:2,,,,,,,,,,,,,,,,,,,,,,

message from VWZ:
1076b512030f0001 - some VWZ status information comprising system pressure and supply temp of backup heater and some unknown values

line from CSV:

*r,,,,,,B512,,,,,,,,,,,,,,,,,,,,,,,,,
r,,StatusVWZ_001,,,,,0F0001,,,UCH;UCH;UCH;temp:supplyimmersionheater;press10:WaterPressure;UCH,,