To provide a regulation means which can regulate an A/D value using a simple and low-cost constitution, and enables easy automation of regulation work.

This device is provided with an analog input means which measures control data and converts them into a fixed voltage signal, an A/D converter which turns the voltage signal into a numerical value and converts it into an A/D value, a nonvolatile storage means which fixedly stores the regulation value composed of a plurality of reference values (IL) and (IH) and recognition values (OL) and (OH), and a regulation control means which performs the converting operation of the A/D value (I), based on a conversion formula derived from these regulation values (IL), (IH), (OL), and (OH), and also the setting of the regulation values (IL), (IH), and (OL) using a setting means from a terminal device or the like is made settable.