PURPOSE: To facilitate the maintenance and operation by providing terminal connection processing of control information such as switching of transmission data and control information, transmission speed of terminal input/output code and speed conversion of code transmission speed of exchange main switch processing to a terminal connection section of electronic exchange without provision of various means for exchange control to a terminal equipment.

CONSTITUTION: A data control switch 32 switches a transmission data transmitted/ received between data terminal equipments via a high speed transmission line 20 and control information transmitted/received between a terminal equipment 10 and an electronic exchange 30 and gives the transmission data to a speed converter 33 and control information to a microprocessor 35. While the speed converter 33 is given to the terminal equipment 10 via a high speed transmission line, the data is given to a main switch of the electronic exchange 30 via a switch path 31 and the mutual conversion subjected to input/output of the terminal equipment 10 for the code transmission speed and that processed by the master switch is executed. A microprocessor 35 transmits/receives control information with the terminal equipment 10 via a data control switch 32 to control the communication processing of the terminal equipment 10 and supports the exchange processing of the electronic exchange 30. Thus, the maintenance and operation are facilitated.