Modbus Error: [Input/Output] Modbus Error

[MrMontesa]

Hey there,
I got my PV system installed last week (SH10.RT and BYD 7.7) and wanted to get the details in my homeassistant setup. After reading here, I moved from the WiNet-S Wifi module to the native LAN port and gave it a static IP via DHCP. I can also telnet TCP/502 on the IP, so network side seems to be ok.
But I cant get values out of the system. I always get the error message:

Logger: homeassistant.components.modbus.modbus
Source: components/modbus/modbus.py:396
Integration: Modbus (documentation, issues)
First occurred: 13:12:01 (1 occurrences)
Last logged: 13:12:01

Pymodbus: SungrowSHx: Modbus Error: [Input/Output] Modbus Error: [Invalid Message] No response received, expected at least 8 bytes (0 received)

Any idea what could be wrong?
Thanks much for your help

Edit: btw, I read some back and forth on the WiNet.-S dongle setup. I'd be happy to do some testing if needed.

Edit2:
Just tested with QModMaster and cant get it to work eitehr.

Is there anything I have to set on the inverter?

[mkaiser]

Hi,

Please check the modbus slave Id. Maybe there is an issue.

[MrMontesa]

Thanks for your swift reply. I tested with different slave ID with no change in behavior. Few hours later it suddenly started working and all values are populating now. Not sure what changed though.