Number of Bus Terminals: 64 (255 with K-bus extension)
Max. number of bytes fieldbus: 1024 byte input and 1024 byte output
Digital peripheral signals: 8,192 inputs/outputs
Analog peripheral signals: 256 inputs/outputs
Configuration: via KS2000 or EtherCAT (ADS)
Protocol: EtherCAT
Data transfer rates: 100 Mbit/s

Hybrid Coupling: Connects EtherCAT Terminals (EL/ES series) with Bus Terminals (KL series) for flexible system design.
High Data Capacity: Supports up to 1024 bytes input and 1024 bytes output via fieldbus for large-scale applications.
Extensive I/O Support: Manages up to 8,192 digital signals and 256 analog signals for complex installations.
Fast Communication: Operates on the EtherCAT protocol with 100 Mbit/s transfer rates for real-time data exchange.

The Beckhoff BK1250 Compact Coupler is a versatile and space-saving device designed to seamlessly connect two of Beckhoff’s modular I/O systems: the EtherCAT Terminals (EL/ES series) and the Bus Terminals (KL series). By bridging these technologies, the BK1250 provides engineers with a flexible tool for integrating legacy KL terminals into modern EtherCAT environments without compromising performance or expandability.

Supporting up to 64 Bus Terminals, and expandable to 255 using a K-bus extension, the BK1250 offers a high degree of scalability for systems of varying size and complexity. This allows users to integrate both digital and analog I/O terminals into a single unified control architecture. With the ability to process up to 1024 bytes of input data and 1024 bytes of output data via fieldbus, the BK1250 is well suited for applications requiring large process images and high signal throughput.

The coupler can handle an impressive number of signals, with up to 8,192 digital I/O points and 256 analog channels, making it ideal for installations where a large number of devices must be monitored or controlled. Its capacity ensures that both compact machines and extensive process plants can benefit from the flexibility of mixed I/O systems.

Operating on the EtherCAT protocol at 100 Mbit/s, the BK1250 ensures high-speed, deterministic communication across the network. This real-time capability is particularly valuable in applications such as machine automation, motion control, and process monitoring, where precise synchronisation and fast data updates are essential.

Configuration of the BK1250 is simple and can be carried out using Beckhoff’s KS2000 software or via EtherCAT (ADS). This ease of configuration reduces engineering effort, enabling fast commissioning and straightforward integration into existing projects. Diagnostic LEDs provide clear visual feedback on operating states and communication, further simplifying setup and maintenance.

The compact form factor of the BK1250 makes it easy to install in control cabinets without taking up excessive space. Its robust design ensures long-term reliability in industrial environments, withstanding the demands of continuous operation in manufacturing, process, and building automation systems.

In practice, the BK1250 is especially useful in retrofit projects, where existing KL Bus Terminals need to be integrated into new EtherCAT-based systems. It also benefits hybrid installations, where both KL and EL terminals are used side by side, offering a cost-effective and flexible migration path to newer technologies.

In summary, the Beckhoff BK1250 Compact Coupler provides a powerful and efficient bridge between Bus Terminals and EtherCAT Terminals. With support for large process images, high I/O capacity, fast EtherCAT communication, and easy configuration, it offers engineers a future-proof solution for combining legacy and modern I/O systems in scalable automation projects.