SAJ Solar inverter

giorgioven9 · June 4, 2024, 1:46pm

Hello everyone, i have a SAJ H1-6K-S2 that is already integrated in Home Assistant via esolar. (data poll every 5 minutes).
P.S. the inverter is already connected via modbus to a meter (chint DSU666).

After reading some posts i decided to try to reach my inverter via modbus so i can poll data every minutes.
So after I checked out if port 502 of my AIO3 was open (and infact it was) I setted up all modbus parameters in Home Assistant.

The good news is that everything works fine!! I can now poll data from my inverter every 60 seconds!!

The bad news is that every couple days, totally random, the connection via modbus to my inverted drop and i receive on Home Assistant the following error:

2024-05-23 13:00:19.466 DEBUG (MainThread) [pymodbus.logging] Adding transaction 1
2024-05-23 13:00:19.466 DEBUG (MainThread) [pymodbus.logging] Resetting frame - Current Frame in buffer - 
2024-05-23 13:00:19.466 DEBUG (MainThread) [pymodbus.logging] send: 0x0 0x1 0x0 0x0 0x0 0x6 0x1 0x3 0x40 0xab 0x0 0x1
2024-05-23 13:00:19.478 DEBUG (MainThread) [pymodbus.logging] recv: 0x0 0x1 0x0 0x0 0x0 0x3 0x1 0x83 0x2 old_data:  addr=None
2024-05-23 13:00:19.478 DEBUG (MainThread) [pymodbus.logging] Processing: 0x0 0x1 0x0 0x0 0x0 0x3 0x1 0x83 0x2
2024-05-23 13:00:19.478 DEBUG (MainThread) [pymodbus.logging] Factory Response[131]
2024-05-23 13:00:19.478 DEBUG (MainThread) [pymodbus.logging] Getting transaction 1
2024-05-23 13:00:19.478 DEBUG (MainThread) [pymodbus.logging] Frame check, no more data!
2024-05-23 13:00:19.478 ERROR (MainThread) [homeassistant.components.modbus.modbus] Pymodbus: modbus-saj: Error: device: 1 address: 16555 -> pymodbus returned isError True

I tried many times to connect via modbus to my inverter again but i always received the same error.

In the meantime I decided to comment (#) the line related to modbus connection from my configuration.yaml

After couple days i tried again to established a connection to my inverter and… everything worked fine!! SO, why I received the error? Why every couple days, totally random, the connection drop and it is immpossible for me reach the inverter via modbus? And why a couple days after the connection drop, if I retry, everything works fine??

Thank you very much!!

gerbenz · June 4, 2024, 5:33pm

Thanks,

I have seen that.
But how connect the modbus to wifi dongle to the inverter.

Do i need unscrew ethernet adapter and can i then connect modbus to wifi dongle?

buggit · June 18, 2024, 8:33am

Hi @pdeneve and @stanus74 thanks for your effort on this - i am also stuck at the same point as @pdeneve

can connect a session via python or qmodmaster to the Aio3 but doesnt return any data
very different version (firmware = 1.201, hardware = 3.0)

Any other ideas ?

stanus74 · June 18, 2024, 2:34pm

the connection with AIO3 to modbus is not very stable.
I have programmed extra queries in my Home Assistant integration to check the connection in the event of errors and to reestablish it. But it only works for H2/H2S inverters

With a Modbus to TCP converter, the connection is much more stable, e.g. ELfin EE10a

stanus74 · June 18, 2024, 2:35pm

use an Elfin EE10a. I have already tested it with this and the connection is stable and fast

stanus74 · June 18, 2024, 2:37pm

I have also tested this variant with an ESP32 via Bluetooth. It worked similarly to direct via AIO3

buggit · June 18, 2024, 11:39pm

Dam, I’ve got an r5 varient three phase and it’s erroring out. And other tips?

stanus74 · June 19, 2024, 5:41pm

the R5 has an RS485 port. You can connect an Elfin EW11 directly. The port supplies 7v on one pin to operate the Elfin without an extra power supply unit.

A Home Assistant integration is available on github

The connection of the pins is also explained there (also on the RS232 port where the AIO3 is normally plugged in)

buggit · June 28, 2024, 6:30am

Thanks finally had my elfin arrive - my inverter also has a DRM port - can i use this?

gerbenz · June 29, 2024, 12:58pm

Hello, i see youre post about modbus
Can u help me?

I have a saj sununo plus 3K-M
And connected Hf Elfin-EE10A
But cant read something.

Can u tell me exactly how u did and what custom component u use?
I tryed saj r5 inverter modbus.
My settings on saj inverter are:
Modbus baudrate: 115200
Adress: 1

buggit · June 30, 2024, 2:59am

Thanks - am so close now. Got a EW11 and have done the correct pinout and setup. Have connnected it to home assistant but all sensors are recording a status unknown - when i check the log everything is successful - are the settings different in an EW11 v EW10?

stanus74 · June 30, 2024, 8:14am

try change cable RS485_A+ <> RS485_B+

use QModmaster to check whether you can read registers manually.QModMaster - Browse Files at SourceForge.net

stanus74 · June 30, 2024, 8:32am

Baud rate must be the same everywhere

Check frames counting

If you do not see any send/receive bytes, there are still errors in the settings or cabling

gerbenz · June 30, 2024, 8:46am

hello,
here also says unknown
i have no errors

inverter is: Saj sununo plus 3m-k

buggit · June 30, 2024, 11:49pm

Ok - so getting a timeout

Settings in elfin

buggit · July 1, 2024, 12:58am

what about sent but not recieved?

buggit · July 1, 2024, 6:16am

Swapped the cords over and down I see serial connection frames recieved and transmitterd - but still cant use QMOD master

stanus74 · July 1, 2024, 6:34am

try these settings

you can also switch Unit 0 to 1 and test again

change the Port in Settings to 502

watch Video (its in spain but you see the settings)

buggit · July 1, 2024, 6:45am

Thanks ive applied those settings - can see below that my computer is connected to it

still getting Timeout error for unit 0 and 1

Ill watch the video now! Feel like im really close! Since there is messaging under the seral port (sent and received) does this mean the error is between the mobus and my home assistant/laptop?

stanus74 · July 1, 2024, 7:00am

try IP 192.168.86.193