PURPOSE: To expand command console operating service functions and to reduce the mounting space by providing plural key mats to a command console operating panel and a means for coding key operation information and sending the coded operation information from the command console to a controller.

CONSTITUTION: An interface section with a command console 2 and a control section of a command telephone set 3 are mounted in a controller frame 1. Control buttons mounted on the command console are integrated to key mats 3111 of a multi-item input device 311, the key operation information of the mat 3111 is coded and sent from a data control line to a controller 32 via an interface 3112. Thus, the command console operating service function is expanded in this way and the mounting space is saved.