COMMUNICATION CONTROL EQUIPMENT

PURPOSE:To improve operability, and at the same time, to prevent the decrease of reliability due to mis-setting, in a communication control device to be provided in a terminal equipment to transmit and receive data to and from a common transmission line by providing a means to calculate automatically a belonging group number from a set self address. CONSTITUTION:Switches 25, 26, 27 set up the lowest order bits b0, b1, b2 of the self address. When a received packet is a multiple address packet, an adder 29 adds '4' or '0' to the output contents from a register 28 according as the contents of b0 is '1' or '0' respectively, and outputs them. Next, the adder 30 adds '2' or '0' to the output contents from the adder 29 according as the contents of b1 is '1' or '0' respectively, and outputs them. Next, the adder 31 adds '1' or '0' to the output contents from the adder 30 according as the contents of b2 is '1' or '0' respectively, and outputs them as R. R is the group number to be required. An AND circuit 34 takes the logical product of R-th power of 2 and a transmission destination address 33 of the received packet, and if the result S is other than '0', it decides that the packet is addressed to its own group, and transfers the packet to a host terminal.