OMRON CS1W-CLK21-V1 Controller Link Unit

The OMRON CS1W-CLK21-V1 is a high‑speed Controller Link network unit designed for the CS1 series programmable logic controllers. This intelligent communication module provides optical fiber connectivity to a Controller Link network, enabling fast, reliable data exchange between multiple PLCs, personal computers, and other automation devices in a distributed control architecture. The V1 suffix indicates enhanced performance with improved network stability and extended functionality.

The Controller Link network uses a token‑passing protocol and offers data transfer rates of up to 2 Mbps over a large‑scale network (up to 32 nodes per segment, 62 nodes with repeaters). The CS1W‑CLK21‑V1 supports both event‑driven and time‑stamped communications, making it suitable for applications requiring coordinated control over multiple machines or process areas. Its optical fiber interface provides excellent noise immunity and allows cable runs up to 500 meters between nodes.

Technical Specifications

• Network type: Controller Link (OMRON proprietary)

• Communication medium: Optical fiber (duplex, glass or plastic fiber)

• Transmission speed: 2 Mbps

• Maximum nodes per network: 32 (without repeaters), 62 (with repeaters)

• Maximum cable length (per segment): 500 m (glass fiber), 200 m (plastic fiber)

• Communication protocol: Token‑passing with data link and message services

• Data link area: Up to 2,000 words (shared memory)

• Message service: Read/write PLC memory, remote programming, and event logging

• Network diagnostic functions: Built‑in loopback test, node status monitoring, and error logging

• Power consumption: 5 V DC, 300 mA (from backplane)

• Dimensions: Standard CS1 module (single slot)

• Operating temperature: 0°C to +55°C

Functional Capabilities

• Data link (shared memory): The unit automatically exchanges data between participating PLCs in a cyclical manner, allowing real‑time synchronization of machine states.

• Message communications: The PLC program can send explicit commands (e.g., read/write memory, start/stop remote PLCs) to other nodes using the message service.

• Network redundancy: The optical fiber interface supports both ring and daisy‑chain topologies, with built‑in loopback detection to bypass broken fiber segments.

• Event logging: The unit can record communication errors and node status changes, aiding in post‑incident analysis.

Typical Application Scenarios

• Multi‑machine coordination: Synchronizing the operation of several machines in a production line via shared data.

• Remote I/O systems: Connecting distributed I/O racks to a central CPU over long distances.

• SCADA integration: Linking PLCs to a supervisory PC for data acquisition and control.

• Process islands: Interconnecting multiple control panels in a plant area.

Installation and Network Configuration

Mount the CS1W‑CLK21‑V1 into any available slot in the CS1 rack. Connect the optical fiber cables to the transmitter (TX) and receiver (RX) ports. Network configuration is performed using CX‑Net or the PLC’s programming software, where users set the node number, data link allocations, and communication parameters. The unit supports auto‑detection of network topology and automatically adjusts timing. Each node on the network must have a unique node address (1‑32). The data link is defined by specifying the sending and receiving ranges in the PLC memory. After configuration, the network can be monitored online for diagnostic purposes.

Compliance and Safety

The CS1W‑CLK21‑V1 is CE marked and UL recognized. It complies with EN 61131‑2 and is RoHS compliant. The optical transceiver is Class 1 laser compliant, ensuring eye safety.

Conclusion

The OMRON CS1W‑CLK21‑V1 Controller Link unit provides a robust, high‑speed communication backbone for CS1 PLC networks. Its optical fiber interface, diagnostic capabilities, and flexible data exchange make it an essential component for large‑scale, distributed automation systems.