Ultisolar evacuated tubes controler

I have a solar boiler and the controler has a RS232 over RS485 port. The sofware that comes with the system is very basic. I took an Arduino with RS485 adapter to listen in on the communication. I can see distinct values. Every few seconds I see a string as shown in the graph. Left is the original sofware, right is serial port terminal (listen only). I can change settings in the original software and check the terminal to see how that matches any change in the string.
My goal is to decode the string (match positions with functions and data) and to display the data in HA. The ultimate goal is to be able to CHANGE settings from within HA.

Can someone point me in the right direction where to go from here?

I also have an Ultisolar controller; SR1168C. Mine is hooked up to a serial device server and I’ve been dumping statistics from it for several years; I’m considering adding it to Home Assistant. Just found your post after starting to assemble the pieces of the puzzle.

When I originally hooked this up with my own scripts, I noticed that there was an Excel sheet somewhere in the directory structure of Ultisolar software; that Excel sheet happened to contain a full description of all registers.

What controller model do you have, and can you also find an Excel with register descriptions?

FWIW: there are 5 different command sequences, each is 8 bytes - and iirc all the replies are 37 bytes (including some start/stop markers and checksums)

Hi Jeroen, I have a SR1188. I noticed that Excel sheet too.
Here’s a part of it.