PROBLEM TO BE SOLVED: To provide an input circuit and an input method of simulated analog signals which enable easy simulated analog signal input and power supply to a transmitter when performing a calibration test. SOLUTION: The control device includes a transmitter 5 which detects a process amount of a plant and outputs it as an analog signal, a distributor 3 which supplies power to the transmitter, receives the analog signal and converts it into a current/voltage signal, and a measurement control circuit 7 which performs operations using the output signal from the distributor. The distributor includes a switching circuit 8 which switches input circuits and inputs an simulated analog signal by switching the switching circuit at a calibration test. The input method of a simulated analog signal also inputs the simulated analog signal by switching the switching circuit at a calibration test. COPYRIGHT: (C)2010,JPO&INPIT
