Omron Corporation CJ1W-CT021 High-Speed Counter Unit

The Omron CJ1W-CT021 High-Speed Counter Unit is a two-channel counter module for Omron CJ1-series PLCs that processes high-frequency pulse signals for precise counting and position tracking in automation equipment. It accepts pulse inputs compatible with incremental encoders, supports up/down counting, frequency measurement, and position control, and delivers high-speed counting up to several hundred kHz. The unit mounts in a CJ1 PLC rack via screw terminals, provides electrical isolation between input and PLC, and operates from 0°C to +55°C. Common applications include encoder-based positioning, conveyor synchronization, packaging machinery, and automated inspection systems; common replacements are CJ1W-CT041, CJ1W-CT021-V1, and NX-CT2605.