PURPOSE: To make processing opportunities for all terminal equipments uniform, by starting processings in order from operation requests of terminal equipments, which cannot be processed in the preceding cycle, in the next cycle if all operation requests from terminal equipments cannot be processed in one cycle.

CONSTITUTION: A terminal controller 1 scans and processes button operation information from n-number of multifunctional telephone sets KT-0∼K-(n-1) through a telephone set interface 11 and transmits them through a central processing device interface 7. The number of the first terminal equipment with which scanning should begin is stored in a terminal equipment discrimination information storing means 9 as an n-adic counter. At a scanning start time, the scan processing is executed in order from the terminal equipment having this stored number; and each time one terminal is scanned, 1 is added to the storing means 9 independently of the presence or the absence of button information. The number of processings for the presence of button information is counted in a memory 10; and when the counted value becomes a certain value, one scanning cycle is terminated, and the number of a terminal which should be first scanned in the next scanning cycle is set in the storing means 9.