GE’s Fieldbus network adapters provide the interface between modular I/O stations and the chosen fieldbus. They handle all data and diagnostic traffic and supply power to the attached modules. These DIN‑rail devices are passive, IP20‑rated and draw from the PLC’s power supply. Various versions support different protocols (Profinet, Profibus, Ethernet/IP), each with specific temperature and mounting requirements. They’re essential for RSTi‑EP systems but add another proprietary component to manage; some users may prefer I/O platforms with integrated networking to reduce parts count.