The Omron CJ1W-CLK21-V1 is a Controller Link Unit (CLU) designed to enable high-speed and reliable communication between multiple CJ1W-series PLCs and computers. It supports data transmission rates of 500 kbit/s, 1 Mbit/s, or 2 Mbit/s over a shielded twisted-pair cable, with a maximum transmission distance of up to one kilometer depending on the selected speed. Operating at a rated power of 5V DC and consuming 0.35 Amperes, the CJ1W-CLK21-V1 ensures efficient and stable communication performance. The unit is equipped with a unit number switch for easy network configuration and LED indicators that provide clear visual feedback for status monitoring and troubleshooting. This controller link unit may be used in automation systems across North America, Europe, Asia, and worldwide, delivering dependable network connectivity and simplified setup for Omron PLC communication networks.