SH5K - the EMS mode change is not working

[leonjz]

@mkaiser Thank you for your fantastic job on this project. I tried the installation and HA can get the sensor values from time to time, from 24 hour curve, I found it can retrieve for example the battery voltage every 30 minutes. not the scan interval defined the cfg 10seconds. But that's not the key issue, the main purpose is to use HA to control the forced discharge. (EMS forced mode), I tried both the selection and run the automation manually, the mode can't be changed successfully at the inverter side (although I can change it from the APP wifi local access), This integration with HA used the inverter's LAN port (as suggested, not wifi). when I run the write_register funtion manually to set 2 on address 13049, I got the returned error like: Pymodbus: SungrowSHx: Modbus Error: [Input/Output] Modbus Error: [Invalid Message] No response received, expected at least 8 bytes (0 received)
do you think the register is locked from writing? would it needs setting a user/pass in some register address to enable the write?

My SH5K off grid capable inverter is about 5 years old ( four button version).