This is a proposal to replace the `match/case/case...` by `if/elif/elif.../else` in the function `.decode()` to ensure compatibility with python 3.9 and earlier.
The use of `match/case` in this function is the only place in the whole package where a construction requires python >= 3.10. The proposed modification seems worth because python 3.9 is still widely used; it is e.g. the version available in Debian/oldstable repositories, which is still supported.

This is a proposal to reintroduce the '.connected` attribute.
Its suppression in recent versions of the module causes errors in programs using earlier versions.
In this proposal, an equivalent is reintroduced, now as a property, relying directly on the new `.isConnected()` method.

Retro-compatibility with python 3.9

Reintroduce `.connected` attrubute

This proposal implements an own logger for the `sun2000_modbus.inverter` module. 
Before, it was using the default "root" logger. If a program using the module needed to mute its log messages, the only option was to mute the "root" logger, which also muted messages from all other loggers.
A module-specific logger can be tuned without impact on other loggers and its messages will clearly display their origin as "sun2000_modbus.inverter" instead of "root".

Usage examples (in a custom program):
1°) catch the logger
    inv_log = logging.getLogger("sun2000_modbus.inverter")
2°) use one of the following instructions
    inv_log.setLevel(logging.INFO)  # original behaviour
    inv_log.setLevel(logging.ERROR)  # or any other level
    inv_log.disabled = True  # disables this logger only

Implement sun2000_modbus.inverter own logger

This proposal implements the formatting numbers with the proper thousand separator and decimal sign according to the locale for the `.read_formatted()` function.

To use this feature, a module should at first
`
    import locale
    locale.setlocale(locale.LC_ALL, '')
`
and then call `.read_formatted()` with the named parameter `use_locale` set to `True`, for example: `read_formatted(register, use_locale=True)`.