Can I individually zero the per-phase energy registers EnergyA, EnergyB, and EnergyC on the WattNode Modbus?
Unfortunately, we only support zeroing all energy registers simultaneously using the ZeroEnergy register.
An alternative is to compute difference data for each per-phase register. In other words, to track EnergyA for some period of time, at the start of that time interval, record the EnergyA value. Then subtract that recorded value from new EnergyA readings to simulate zeroing EnergyA.
Example
| Time | EnergyA | Offset | Difference Data | Notes |
|---|---|---|---|---|
| 05:30 | 318.9 kWh | 0.0 kWh | 318.9 kWh | First interval |
| 05:45 | 331.3 kWh | 0.0 kWh | 331.3 kWh | First interval |
| 06:00 | 345.5 kWh | 345.5 kWh | 0.0 kWh | Start of second interval |
| 06:15 | 359.0 kWh | 345.5 kWh | 13.5 kWh | Second interval |
| 06:30 | 371.2 kWh | 345.5 kWh | 25.7 kWh | Second interval |
| 06:45 | 385.3 kWh | 345.5 kWh | 39.8 kWh |
- Note: the ending energy for the first interval can be stored just before loading the new offset value.