TCP Modbus

[unaxboy]

Are you sure it's float16 on ModBus side? float16 is KNX-specific datatype and I've only seen one ModBus AC unit which has it as register value. Also, second mb:readregistervalue() parameter must be a string, not a dt.something. Do you have documentation for your ModBus device?

Yes, here it is

Now I try to read jus a outdoor temp. to get started. In the documentation its 129 address, but I'm trying with all 128, 129 and 130 to be sure

I try do the same, but with writable addresses (315, 513, 533, 771, 1050).

Please, can someone help?