The Yokogawa NFAI135-S51 is a high-performance, 16-channel Analog Input Module designed for the ProSafe-RS safety instrumented system (SIS) or the CENTUM VP integrated production control system. It serves as a critical interface between field sensors and the control system, specializing in reading 4 to 20 mA DC current signals from devices such as pressure transmitters, temperature transmitters, flow meters, and valve positioners.