The Yokogawa F3SP35-5N is a Safety Programmable Controller (Safety PLC) module. Specifically, it is a 5-number of I/O (Input/Output) safety control unit.
This compact and self-contained unit integrates a CPU, power supply, and I/O into a single module. It is designed to execute critical Safety Instrumented Functions (SIFs) up to SIL 3 as defined by IEC 61508 standards.