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This page describes the "property request" mechanism, as well as the message format used to interact with it.

Message Format

All messages on this endpoint are CBOR encoded.


Requests are maps, with one or more of the following keys:

  • get: An array of property IDs to read
  • set: A map containing properties to set. Keys in the map correspond to property IDs.


The device responds with a map, which contains the following keys. Which keys are included in the response depends on the request:

  • get: A map (keyed by property IDs) containing the value of all requested properties. Unsupported/unknown properties are returned as undefined.
  • set: An array containing the property IDs of all properties that were set. Any properties that were requested to be set, but are not supported (or read-only) will not be included.

Supported Properties

Below are all currently supported properties, including their IDs and value types:

ID Name R/W Type Description
0x01 HwSerial R string Serial number of the hardware
0x02 HwVersion R string Version information (such as revision) for the device
0x03 HwInventory R array

Information about all peripherals connected to the load. The array contains maps, which will have the following keys:

  • type: Peripheral type; may be one of ["load", "hmi" or "io"]
  • sn: Serial number (string; optional)
  • driver: Driver id (blob; optional)
0x04 SwVersion R string Current software version (including build number)
0x05 MaxVoltage R int Maximum allowable input voltage (mV)
0x06 MaxCurrent R int Maximum allowable input current (mA)
0x07 DefaultVSense RW int

Voltage sense source on power-on:

  • -1 = state at last power off
  • 0 = internal
  • 1 = external

This setting is persistent.

0x08 DefaultMode RW int

Operation mode on power-on:

  • -1 = mode at last power off
  • 0 = Constant current
  • 1 = Constant voltage
  • 2 = Constant wattage¬†

This setting is persistent.

0x09 DefaultCurrent RW int Current limit value (for constant current mode) to apply on power on, in mA. -1 = last user specified value at power off
0x0A DefaultVoltage RW int Voltage limit value (for constant voltage mode) to apply at power on, in mV. -1 = last user specified value at power off
0x0B DefaultWattage RW int Wattage (for constant wattage mode) to apply at power on, in mW. -1 = last user specified value at power off