KL9050 | BECKHOFF | K-Bus Extension Coupler Terminal

Product Overview

The KL9050 (KL9050) is a specialized coupler terminal designed for the expansion of the Beckhoff Bus Terminal system. In large-scale automation architectures where the number of I/O modules exceeds the capacity of a single rail or requires distribution across multiple rows in a control cabinet, the KL9050 acts as the decentralized "receiver" or "sub-coupler." It bridges the internal K-bus signal from a primary Bus Coupler (such as a BK series) or an Embedded PC to an additional segment of up to 64 Bus Terminals. By utilizing standard RJ45 connectivity, the KL9050 enables modular machine designs to remain flexible and scalable while maintaining robust communication across distances of up to 5 meters between stations.

Technical Configuration

The KL9050 hardware functions as a power and signal refresher for the extended K-bus segment. It features two RJ45 sockets (Input and Output) to allow for daisy-chaining multiple extension segments. Internally, it provides a 400 mA current supply to power the logic of the attached Bus Terminals, effectively acting as a localized power supply for the K-bus. The terminal also passes through the 24 VDC power contacts, supporting a current load of up to 10 A for field-side devices. For system diagnostics, an integrated green Power LED provides immediate visual confirmation of the 24 V supply status. The module is fully certified for marine applications (DNVGL) and hazardous areas (ATEX), ensuring reliable operation in demanding environments.

Technical Specifications

Technical FAQs

How do I connect the KL9050 to the main Bus Coupler?

The KL9050 must be used in conjunction with a KL9020 (End Terminal with RJ45 output) located at the end of the previous terminal block. A standard shielded Ethernet cable (Cat 5 or higher) connects the KL9020 output to the KL9050 input.

What is the maximum number of extension stages allowed?

The Beckhoff K-bus system typically supports several extension stages, provided the total number of terminals across all segments does not exceed 255. Each KL9050 starts a new segment of up to 64 terminals.

Does the KL9050 require its own 24 V DC power supply?

Yes. To power the internal K-bus logic of the new segment and to refresh the power contacts for the field devices, a 24 V DC supply must be wired directly to the KL9050 terminal points.

Engineering & Installation Guide

• Cabling Requirements: Use only high-quality, shielded RJ45 patch cables for the 5-meter connection. In environments with high electromagnetic interference (EMI), ensure the cable shielding is properly grounded to prevent K-bus communication errors or "K-bus Reset" faults in the controller.

• Power Budgeting: Each KL9050 provides 400 mA for the internal K-bus logic. If the sum of the "K-bus current consumption" for all 64 terminals in the segment exceeds this value, you must insert a KL9400 power supply terminal to provide additional current.

• DIN Rail Installation: The KL9050 should be securely latched onto a 35 mm DIN rail. Ensure the PE (Protective Earth) contact on the back of the terminal makes a solid connection with the rail to ensure proper grounding of the internal electronics.

• Hazardous Area Safety: For ATEX "Ex nA" compliance, the unit must be installed in an enclosure with a minimum protection rating of IP54. Do not disconnect the RJ45 cables or field wiring while the system is energized to avoid potential sparking in explosive atmospheres.