Allen-Bradley 845N-SJDN2-CGN1 Optical Incremental Encoder

The Allen-Bradley 845N-SJDN2-CGN1 Optical Incremental Encoder is an optical incremental encoder that converts rotary motion into two out-of-phase electrical signals, providing quadrature feedback for speed and position in automation systems. Part of the 845N family from Allen-Bradley (Rockwell Automation), this variant with SJDN2-CGN1 designation is designed to integrate with standard Allen-Bradley drives, PLCs, and motion controllers that expect incremental pulse outputs. In operation, the encoder generates a pulse train that controllers interpret to determine rotation, direction, and speed, enabling closed-loop feedback and precise control of mechanical systems. The device is intended for industrial environments and is compatible with the broader Allen-Bradley encoder ecosystem, including compatible wiring conventions and accessories used in typical machine automation installations. Applications commonly rely on this type of encoder for reliable rotary feedback in packaging lines, material handling, CNC tooling, robotics, and other automated equipment where consistent pulse signals are essential for accurate control and synchronization. By aligning with Allen-Bradley’s hardware and software interfaces, the 845N-SJDN2-CGN1 supports straightforward integration within existing control architectures and helps ensure consistent, deterministic feedback for motion control tasks.