The Schneider Electric STBDDI3425K is a digital input module from the Modicon STB (Advantys) distributed I/O system. It is designed to connect discrete field devices (such as push buttons, limit switches, proximity sensors, and photoelectric sensors) to a higher-level PLC or industrial controller via a fieldbus network (e.g., PROFIBUS-DP, Modbus TCP/IP, EtherNet/IP, etc., depending on the installed Network Interface Module).