The device controller (DC) monitors and manages either a producer or a consumer of electrical energy. A consumer could be a radio (e.g. HF, FM, VHF, UHF), the navigation lights, interior lights, the fridge or freezer, a fan or a chart plotter. As a special feature, the DC can also work as a dimmer, limiting the current or power going to the device.
It also monitors the bus voltage, the current, as well as the energy in Wh or Ah and logs all those values to the HQ module so they can be analysed at any time.