The Yokogawa CP451-11 is a Signal Conditioner from the UTAdvanced series of DIN-rail mounted instruments. It is specifically designed as a Pulse (Frequency) to Analog Signal Converter.
Its primary function is to accept a pulse or frequency input signal from a field device and convert it into a standardized 4 to 20 mA DC analog output signal. This allows pulse-generating sensors to be easily integrated into process control systems, PLCs, or DCSs that expect a standard analog input.