The Omron CQM1-SRM21-V1 is a CQM1 series master module designed for use with Omron CQM1 programmable logic controllers (PLCs) in CompoBus/S network applications. Operating with a current consumption of 180 mA at 5 VDC, it provides efficient and stable power usage while supporting robust communication capabilities. The module accommodates configurations of either 4 or 8 points per node number, offering flexibility to suit various system architectures and control requirements. Equipped with DIP switches, the CQM1-SRM21-V1 allows straightforward setup and parameter configuration, simplifying installation and maintenance. It is engineered to deliver both long-distance and high-speed communication performance, ensuring reliable data exchange and real-time control in distributed automation systems. The CQM1-SRM21-V1 could be implemented across industrial networks in North America, Europe, Asia, and other global regions, providing dependable and scalable master control functionality within Omron’s CompoBus/S communication framework.