[Bug]: Something went wrong reading from modbus

[matomatusov]

Describe the bug

Hi,
after upgrading the wifi+Lan dongle to 1.005.04, this error appears:

This error originated from a custom integration.

Logger: custom_components.solax_modbus
Source: custom_components/solax_modbus/init.py:670
integration: SolaX Inverter Modbus (documentation, issues)
First occurred: January 10, 2025 at 7:43:05 AM (51 occurrences)
Last logged: 10:32:33 PM

Something went wrong reading from modbus
Traceback (most recent call last):
File "/config/custom_components/solax_modbus/init.py", line 670, in async_read_modbus_data
res = await self.async_read_modbus_registers_all(group)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/config/custom_components/solax_modbus/init.py", line 843, in async_read_modbus_registers_all
data[descr.key] = descr.value_function(0, descr, data)
~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^
File "/config/custom_components/solax_modbus/plugin_solax.py", line 300, in value_function_battery_voltage_cell_difference
return datadict.get("cell_voltage_high", 0) - datadict.get("cell_voltage_low", 0)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TypeError: unsupported operand type(s) for -: 'NoneType' and 'NoneType'

Integration Version

2025.01.6

Homeassistant core version

2025.1.2

Inverter brand

Solax Power

Plugin used

plugin_solax.py

Serial prefix

H34A10

Inverter firmware versions

ARM1.48 DSP1.45

Connection Method

Packet Wifi + LAN 3.0

Dongle firmware

1.005.04

Detailed Error Log

No response

Additional context

No response