Yokogawa NFLR121-S51 S1 Serial Communication Module

The Yokogawa NFLR121-S51 S1 Serial Communication Module is a two-port serial interface for STARDOM and field control systems that enables RS-422/RS-485 communication between a control system and external devices such as PLCs, analyzers, and subsystems. It supports point-to-point RS-422 and multipoint RS-485, with half-duplex or full-duplex operation limited by the wiring method, and data speeds from 0.3 kbps to 115.2 kbps over distances up to 1200 m on RS-485 networks. The module uses ASCII or binary protocol formats and supports 7/8 data bits, selectable parity, and 1–2 stop bits. It connects via a terminal block (M4 screw clamp), draws approximately 0.5 A, and weighs about 0.3–0.34 kg. Commonly deployed in industrial automation, process control, distributed control systems, and automation networks where reliable serial data exchange is required, this module expands network interfaces, replaces existing communication modules, and enables integration with third-party systems in environments such as chemical plants, power generation, and manufacturing.