The Beckhoff BK1120 EtherCAT Bus Coupler is a versatile communication interface designed to connect Beckhoff’s standard Bus Terminals (KL series) to an EtherCAT network. By bridging these modular I/O terminals with the high-speed EtherCAT protocol, the BK1120 provides a flexible and powerful solution for distributed automation systems.

Capable of connecting up to 64 Bus Terminals directly—and expandable to 255 with a K-bus extension—the BK1120 offers exceptional scalability for systems ranging from small-scale applications to large, complex installations. With support for a process image of up to 1024 bytes input and 1024 bytes output, the coupler ensures sufficient bandwidth to handle extensive digital and analog I/O requirements.

The BK1120 integrates seamlessly into EtherCAT networks, utilising the protocol’s 100 Mbit/s data rate and deterministic communication. This high-speed performance ensures real-time responsiveness and precise synchronisation, which are essential in machine automation, motion control, and process applications. Its dual RJ45 interfaces support straightforward daisy-chaining of devices, allowing flexible network topologies including line, star, and tree structures. Standard Ethernet/EtherCAT Cat.5 cabling is used, enabling cost-effective and widely available connectivity.

Configuration of the BK1120 is simple and can be performed via Beckhoff’s KS2000 software or directly through EtherCAT ADS. This flexibility streamlines commissioning and reduces engineering effort, while diagnostic indicators on the housing provide clear operational feedback, supporting fast troubleshooting and system monitoring.

Powered by a 24 V DC supply (-15%/+20%), the BK1120 is robust and reliable, ensuring consistent operation in industrial environments. It is designed for long-term use under continuous operation, making it well suited for demanding automation tasks across industries such as packaging, materials handling, energy management, and building automation.

In practical applications, the BK1120 excels in scenarios where legacy Bus Terminals (KL series) need to be integrated into modern EtherCAT architectures. It provides a cost-effective migration path, protecting existing hardware investments while enabling systems to benefit from EtherCAT’s real-time performance. The coupler also supports hybrid setups, where Bus Terminals are combined with EtherCAT Terminals, allowing flexible system design tailored to the requirements of each project.

In summary, the Beckhoff BK1120 EtherCAT Bus Coupler is a powerful and efficient interface for connecting Bus Terminals to EtherCAT networks. With scalability up to 255 terminals, support for large process images, high-speed communication, and easy configuration, it provides engineers with a reliable and future-proof solution for integrating modular I/O into EtherCAT-based automation systems.