A measurement value output device including measuring unit such as current measuring unit (11) for metering an AC current running through the power line (2) of a motor (1), a detection circuit (12) for detecting the above measurement value by amplifying the above measured current value, a signal converting unit (13) for converting the detected measurement value into a time interval (duration) and an ON/OFF signal output unit (14) for outputting an ON/OFF signal which is kept ON or OFF for the above time interval at predetermined time intervals and outputs the measurement value such as the motor current of a production line used to monitor a measurement value at predetermined time intervals as a pulse signal (digital signal) having a pulse width corresponding to the above measurement value at predetermined time intervals.