Product Description:

The CU1128 is an industrial EtherCAT junction produced by Beckhoff within the CU EtherCAT Junctions series. The module distributes the EtherCAT protocol from an upstream master into several branches, letting automation builders create star or tree layouts that reduce cable lengths and simplify panel wiring. Because it works as a junction rather than a controller, it passes communication between multiple network segments without changing the basic topology of the EtherCAT system. The housing measures 122 mm in width, 38 mm in depth, and 100 mm in height, which helps it fit into compact control cabinets.

It offers a bus interface with 8 x RJ45 sockets, each operating at a line speed of 100 Mbit/s so deterministic cycle times remain constant across all downstream segments. Integrated Distributed Clocks keep node-to-node jitter within the sub-microsecond range, which is essential for synchronized motion or measurement tasks. When tools or workpiece carriers must be exchanged without stopping the controller, the junction’s Hot Connect capability lets a branch be inserted or removed and automatically identified again online. With a maximum station spacing of 100 m per port, standard industrial floor layouts can be reached without repeaters. The shielded cabling design helps maintain EMC compliance in electrically noisy cabinets.

Installation uses a 35 mm DIN mounting rail, and the enclosure carries an IP20 rating, so the unit must be housed in a control panel and protected from dust and tools. Power is supplied through the three-pole connector at 24 V DC, which supports the internal electronics and status LEDs. The network cabling must meet at least the Cat.5 standard, and relative humidity of up to 95% is permitted in non-condensing factory zones. In this type of installation, the enclosure is protected from accidental contact while the branch connections remain easy to access.