What is the frequency measurement resolution of the WattNode?
The resolution is approximately one part in 250, but varies somewhat with the line frequency. So at 50 Hz, the resolution is 0.18 Hz, while at 60 Hz, the resolution is 0.26 Hz.
WattNode Modbus (WNC Series)
If you use the floating point Freq register, the reported value will have several digits to the right of the decimal, but the resolution will only be 0.18 – 0.26 Hz.
If you use the integer frequency register, then the reported resolution will be 0.1 Hz, but the value will step by 0.2 or 0.3 Hz at a time.
WattNode for LonWorks (WNC Series)
For the standard models and Option B models, nvoFreq is a SNVT_freq_f (floating point) and the reported value will have several digits to the right of the decimal, but the resolution will only be 0.18 – 0.26 Hz.
For Option BI models (integer network variables), then nvoFreq is a SNVT_freq_hz with a resolution of 0.1 Hz, but the value will step by 0.2 or 0.3 Hz at a time.