With the PROFIenergy Profile, the switching mechanisms reside inside the ECUs themselves. These ‘understand’ the PROFIenergy commands issued by the controller.
At times determined during configuration or dynamically decided during production the controller sends ‘start pause’ and ‘end pause’ signals to the ECUs. Each ECU then decides how this information is handled using software ‘agents’ embedded in its firmware.
Equipment vendors themselves decide how to optimize the energy management of their own equipment in response to these signals.
This provides great flexibility: for example, a drive may be run down to idle over a 30 second period, or perhaps a production cell requires that a conveyor be slowed first before a robot can be put to ‘sleep’ (see right). If the duration of a pause is long enough perhaps the ECU can be completely disconnected ... but to be ready to re-start its conveyor should be re-started in advance.
PROFIenergy functions are usually deployed in the same controller (e.g. PLC) that is running the automation system but they could reside in a separate energy management controller on the same network. Multi-level ‘sleep modes’ are feasible.