PURPOSE: To perform multiple address information to the optional number of lines which are more than circuits to which one multiple address device is connectable, by connecting the necessary number of calling devices by a special selection signal.

CONSTITUTION: An originating terminal A when having multiple address communication with more than the specific number of terminals sends the special selection signal to a telex exchange 1 to request multiple address communication service fitted with overflow control. The exchange 1 sends out a service identification code which indicates how many calling devices a multiple address calling device 2a requires in response to the selection signal. The device 2a sends a selection signal which means that calling devices one less than necessary calling devices are required to the exchange. The exchange 1 knows the number of the remaining necessary calling devices and call another calling device 2b. Similarly, a necessary number of calling devices are connected one after another. After the connections are made, terminating terminals B are connected in response to their respective calls and the terminal A is allowed to have multiple address communication with all the connected terminals B.