What data does the device capture?

The following is a list of data that the devices capture

Long Energy

Long Energy is sent by the devices to the server upon request. Long Energy entries are stored on the devices on persistent storage in 5min (300 secs) granularity. Long energy delivery is guaranteed - if the device records the data, it will be sent to the server reliably, possibly after a delay.

Short Energy

Short Energy instead is sent by the devices automatically every 5 to 295 seconds (depending on configuration; the default is 30 secs) with no guarantee of delivery. Short Energy entries are not currently stored on the devices and thus can be lost if the device loses connectivity with the server or simply if UDP data is lost during transmission (UDP has no guarantee of delivery).

What measurements do Wattwatchers devices report?

And what do they mean?

Attribute Included in Format Units Description
eReal Short Energy, Long Energy Integer Joules (J) Real Energy.
eRealPositive Long Energy Integer Joules (J) Positive Real Energy. Over the Long Energy period there may be points of negative energy (e.g. drawing energy from the grid) that are "hidden" in the eReal value for the period if the overall total is negative (for example if solar generation results in an overall export for the period). eRealPositive enables you to determine the total positive flows during the period.
eRealNegative Long Energy Integer Joules (J) Negative Real Energy. Over the Long Energy period there may be points of negative energy (e.g. exports to the grid) that are "hidden" in the eReal value for the period if the overall total is positive. eRealNegative enables you to determine the total negative flows during the period.
eReactive Short Energy, Long Energy Integer Joules (J) Reactive Energy.
eReactivePositive Long Energy Integer Joules (J) Positive Reactive Energy.
eReactiveNegative Long Energy Integer Joules (J) Negative Reactive Energy.
vRMS Short Energy Float Volts (V) Volts Root Mean Square (RMS).
vRMSMin Long Energy Float Volts (V) Minimum Volts RMS. As voltage is an instantaneous value, only the minimum and maximum that occurred within the period are reported for Long Energy.
vRMSMax Long Energy Float Volts (V) Maximum Volts RMS. As voltage is an instantaneous value, only the minimum and maximum that occurred within the period are reported for Long Energy.
iRMS Short Energy Float Volts (V) Current Root Mean Square (RMS).
iRMSMin Long Energy Float Volts (V) Minimum Current RMS. As current is an instantaneous value, only the minimum and maximum that occurred within the period are reported for Long Energy.
iRMSMax Long Energy Float Volts (V) Maximum Current RMS. As current is an instantaneous value, only the minimum and maximum that occurred within the period are reported for Long Energy.
frequency Short Energy Float Hertz (Hz) Voltage Frequency. Measured off P1.
eRealKwh Short Energy, Long Energy Float Kilowatt Hours (kWh) Real Energy converted from Joules to kilowatt hours.
eRealPositiveKwh Long Energy Float Kilowatt Hours (kWh) Positive Real Energy converted from Joules to kilowatt hours.
eRealNegativeKwh Long Energy Float Kilowatt Hours (kWh) Negative Real Energy converted from Joules to kilowatt hours.
eReactiveKwh Short Energy, Long Energy Float Kilowatt Hours (kWh) Reactive Energy converted from Joules to kilowatt hours.
eReactivePositiveKwh Long Energy Float Kilowatt Hours (kWh) Positive Reactive Energy converted from Joules to kilowatt hours.
eReactiveNegativeKwh Long Energy Float Kilowatt Hours (kWh) Negative Reactive Energy converted from Joules to kilowatt hours.
pRealKw Short Energy, Long Energy Float Kilowatts (kW) Real Energy converted from Joules to kilowatts. Note this is a conversion of energy to power, thus the prefix changes to p.
pRealPositiveKw Long Energy Float Kilowatts (kW) Positive Real Energy converted from Joules to kilowatts. Note this is a conversion of energy to power, thus the prefix changes to p.
pRealNegativeKw Long Energy Float Kilowatts (kW) Negative Real Energy converted from Joules to kilowatts. Note this is a conversion of energy to power, thus the prefix changes to p.
pReactiveKw Short Energy, Long Energy Float Kilowatts (kW) Reactive Energy converted from Joules to kilowatts. Note this is a conversion of energy to power, thus the prefix changes to p.
pReactivePositiveKw Long Energy Float Kilowatts (kW) Positive Reactive Energy converted from Joules to kilowatts. Note this is a conversion of energy to power, thus the prefix changes to p.
pReactiveNegativeKw Long Energy Float Kilowatts (kW) Negative Reactive Energy converted from Joules to kilowatts. Note this is a conversion of energy to power, thus the prefix changes to p.
powerFactor Short Energy, Long Energy Float Power Factor The calculated power factor for the channel. See [units-conversion.md#calculate-power-factor] for more information.

Single, two and three phase power

See the Background/Concepts section of the phase grouping support note for more information.

Converting energy units

The API provides energy values in Joules, which can then be converted into different units.

"Catch-up" mode

There are circumstances where a device may continue to collect data but be unable to transmit that data to the Wattwatchers system for a period. When the device re-establishes communications with our cloud infrastructure it will progressively send the data it has collected (i.e. it doesn't do this all at once).

When a device is in this mode, data will appear delayed in being available in other parts of the system, e.g. via the API.