Abstract: The access control arrangement controls access to communication channel of a plurality of interconnected units each of which has an own priority assigned to it. Each unit receives from a preceding unit an access request word comprising a plurality of successive request channels to which priorities are assigned and writes its own priority in the corresponding request channel. The request word is then transmitted to a following unit. When preceding unit has a priority exceeding the priority of the considered unit, these preceding units are inhibited from accessing the communication channel. When after a predetermined time interval, the considered unit is not inhibited by any of the following units, it may access the communication channel.