Abstract: A fluid pressure actuator includes: an actuator body which expands and contracts through supply/discharge of a fluid to generate a driving force; a sensor for detecting a condition of the actuator body; and a control part for controlling a fluid regulator for adjusting a pressure of the fluid supplied to and discharged from the actuator body based on a detection signal from the sensor. The sensor is mounted in the actuator body.

Abstract: In a key telephone system comprising a central control equipment and a plurality of key telephones each comprising a plurality of indication lamps for representing current states of subscriber and extension lines, additional functions such as the assignment of incoming ringing, alarm sound, all call, long distance call and international call can be checked by means of the indication lamps of respective key telephones without actually operating the key telephones. The function data stored in a function data memory in the central control equipment is rearranged in accordance with a transmission format and is transmitted to the key telephones just like as the normal use. The functions preset in the key telephone system can be checked easily and promptly on respective key telephones even by a single operator.