Communication device, control method of communication device, external device, control method of external device, and control system

A communication device that transmits a sensor value of a sensor, which is configured to measure a predetermined physical quantity when a measurement target machine operates, to an external device through wireless communication, the communication device comprising:

• a sensor value acquisition part configured to acquire the sensor value;
• a basic data generating part configured to generate basic data as time-series data with reference to the acquired sensor value;
• a differential data generating part configured to generate differential data indicating a difference between the basic data and measurement data as time-series data corresponding to the sensor value acquired from the sensor;
• and
• a communication part configured to transmit the differential data to the external device.