Reading data from Huawei inverter SUN 2000 (3KTL-10KTL) via modbus TCP and RTU

I’m afraid that only makes sense when the incoming data comes with units, and %unit% represents “use what you have”. In this case, there is no “what you have”.
Try [%.1f V]

Okay, so if power is 300W are we comparing with X mW or X kW or X horsepower …
if (power < 0.0 | W) {