A method of operating a plurality of driving units for powering electronic units, the method comprising interchanging a data frame including a bit sequence, between a master control unit (MCU) and at least one of a plurality of driving units at slave nodes, the sequence being divided in fields of consecutive bit strings, the method comprising: - applying an ID field for addressing at least one driving unit , for interchanging data between the master control unit (MCU) and the at least one addressed driving unit , - applying a data field (DATA) comprising information and/or instructions regarding the status of the electronic units of said addressed at least one driving unit , characterized in that applying the ID field further comprises: - indicating the driving unit address using a first bit sub-string (ID15-ID10) comprising N bits, where 2^N is equal or higher than the number of driving units in the plurality of driving units , for applying the data field on the addressed driving unit or ignoring the data field if the driving unit is not addressed - using a receive/transmit (R/T) command bit for assigning values, for allowing the master control unit (MCU) to identify whether data should be received from or transmitted to driving units , or for allowing each addressed driving unit to decode which action is required by the master control unit (MCU) depending on the value assigned to the receive/transmit (R/T) command bit, - using a further function bit (F) including information in the ID field regarding the type of information and/or instructions included in the data field, - depending on the value assigned to the function bit (F), assigning, in a second bit sub-string (ID7-ID2) of the ID field, data bits in the data field to different electronic units of the addressed at least one driving unit or performing a length decoding step for indicating the length of the bit string in the data field using that second bit sub-string (ID7-ID2). - applying an ID field for addressing at least one driving unit , for interchanging data between the master control unit (MCU) and the at least one addressed driving unit , - applying a data field (DATA) comprising information and/or instructions regarding the status of the electronic units of said addressed at least one driving unit , characterized in that applying the ID field further comprises: - indicating the driving unit address using a first bit sub-string (ID15-ID10) comprising N bits, where 2^N is equal or higher than the number of driving units in the plurality of driving units , for applying the data field on the addressed driving unit or ignoring the data field if the driving unit is not addressed - using a receive/transmit (R/T) command bit for assigning values, for allowing the master control unit (MCU) to identify whether data should be received from or transmitted to driving units , or for allowing each addressed driving unit to decode which action is required by the master control unit (MCU) depending on the value assigned to the receive/transmit (R/T) command bit, - using a further function bit (F) including information in the ID field regarding the type of information and/or instructions included in the data field, - depending on the value assigned to the function bit (F), assigning, in a second bit sub-string (ID7-ID2) of the ID field, data bits in the data field to different electronic units of the addressed at least one driving unit or performing a length decoding step for indicating the length of the bit string in the data field using that second bit sub-string (ID7-ID2). <EOS>