The objective of the invention is a backplane bus especially for equipment cabinets which allows an increase of the bus transmission capacity and this way a considerable increase in the number of plug-in units connected to the bus. The bus is divided physically into two bus segments A and B. The segments are combined into one logical bus by bridging, but so that the bridging function is not performed on the bus but with a plug-in unit (4A, 4B) which is connected to the bus at the point of division and which performs the bridging functions. The plug-in unit makes sure that when a plug-in unit located in the first half of the bus is transmitting to a plug-in unit located in the second half of the bus, the transmission time slot will be properly mapped into the reception time slot of the target plug-in unit in the second bus and vice versa. Hereby the time slot in the first half and the target time slot in the second half form a logical channel which may be allocated on the same principles as a one-timeslot channel.