BECKHOFF

BECKHOFF BK4020 Interbus Bus Coupler

SKU BK4020

In stock
  • 12-month warranty
  • Free returns within 30 days
  • Manufacturer: BECKHOFF

  • Product No.: BK4020

  • Country of origin:Germany

  • Product Type: Interbus Bus Couplers

  • Payment: T/T, Western Union

  • Weight: 170g

  • Shipping port: Xiamen

  • Warranty: 12 months

Description

The BECKHOFF BK4020 is a high-performance Interbus Bus Coupler designed to connect modular Beckhoff Bus Terminals to the Interbus fieldbus system. Serving as the primary physical and logical link between the higher-level fieldbus network and the local K-bus, this coupler automates the mapping of digital, analog, and specialty process signals. The unit compiles these inputs and outputs into a structured process image that is transmitted over the network to the central controller.

The BECKHOFF BK4020 supports standard Interbus data transfer rates of 500 kbaud. It features two 9-pin D-sub connections, consisting of a plug and socket, which include screening and a vibration lock to ensure stable and noise-immune communication in industrial environments. Up to 64 individual Bus Terminals can be connected directly to a single coupler, and this capacity can be expanded up to 255 terminals using K-bus extension modules.

Features

  • Direct integration of BECKHOFF Bus Terminals into Interbus systems.
  • Supports up to 64 standard Bus Terminals directly, and up to 255 terminals via K-bus extension.
  • Dual 9-pin D-sub connectors (plug and socket) featuring integrated screening and vibration locks.
  • Automatic configuration of digital, analog, and complex terminal diagnostic data.
  • Clear status indication via diagnostics LEDs for K-bus status, Interbus traffic, and power supply.
  • Configurable using the KS2000 configuration software.

Applications

  • Interbus-based distributed industrial control environments.
  • Modular and scalable field I/O systems in plant automation.
  • Machine control architectures utilizing modular digital and analog signals.

Technical Specifications

General

Manufacturer BECKHOFF
Model BK4020
Product Type Interbus Bus Coupler

Communication and I/O

Fieldbus System Interbus
Data Transfer Rate 500 kbaud
Bus Interface 2 x D-sub, 9-pin (plug and socket) with screening and vibration lock
Max. Number of Bus Terminals 64 (up to 255 with K-bus extension)
Max. Fieldbus Process Image 64 bytes input, 64 bytes output
Digital Peripheral Signals 512 inputs/outputs
Analog Peripheral Signals 32 inputs/outputs

Electrical

Power Supply Voltage 24 V DC (-15% / +20%)
Input Current 70 mA + (total K-bus current)/4, max. 500 mA
Starting Current Approx. 2.5 x continuous current
Recommended Fuse Less than or equal to 10 A
K-bus Current Supply 1750 mA
Power Contacts Max. 24 V DC / Max. 10 A
Electrical Isolation 500 V (power contact / supply voltage / fieldbus)

Mechanical and Environmental

Weight Approx. 170 g
Operating Temperature 0 to +55 degC
Storage Temperature -25 to +85 degC
Relative Humidity 95%, non-condensing
Protection Class IP20
Installation Position Variable
Vibration and Shock Resistance Conforms to EN 60068-2-6 / EN 60068-2-27
EMC Immunity and Emission Conforms to EN 61000-6-2 / EN 61000-6-4

Connections / Interfaces

Interface or Terminal Function
Interbus Input (9-pin D-sub Plug) Incoming Interbus line connection
Interbus Output (9-pin D-sub Socket) Outgoing Interbus line connection to next node
Power Feed-in Terminals 24 V DC connection for electronics and K-bus
Power Contacts Automatic distribution of 24 V DC field power to adjacent terminals

Installation Guidelines

  1. Ensure all electrical supplies to the system are completely de-energized before mounting, wiring, or removing any components.
  2. Mount the BECKHOFF BK4020 on a standard 35 mm DIN rail (EN 60715) inside a dry, dust-free control cabinet with at least an IP20 protection rating.
  3. Securely slide the coupler onto the DIN rail, verifying that the lock mechanism clicks into place.
  4. Align and slide the required Bus Terminals onto the right-hand side of the coupler. Ensure the tongue-and-groove system and physical contacts align smoothly.
  5. Connect the incoming Interbus cable to the 9-pin D-sub plug and the outgoing link to the 9-pin D-sub socket, securing the physical vibration locks.
  6. Connect a 24 V DC power source to the designated terminal points on the coupler to supply the internal logic, K-bus, and field-side power contacts.
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Shipping & Returns

Global Express Shipping

  • Standard Delivery: 4–6 business days via DHL, FedEx, and UPS.
  • Express Dispatch: Same-day dispatch for in-stock orders placed before 2:00 PM (GMT+8).
  • Worldwide Coverage: Serving over 150 countries.

Returns & Warranty

  • 30-Day Guarantee: Returns accepted for in-stock products in original, factory-sealed packaging.
  • 12-Month Warranty: Every industrial component is backed by our technical warranty.
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Global Express Shipping

  • Standard Delivery: 4-6 Business Days via DHL, FedEx, and UPS.
  • Express Dispatch: Same-day dispatch for in-stock orders placed before 2:00 PM (GMT+8).
  • Worldwide Coverage: Serving over 150 countries, including rapid delivery to Saudi Arabia and UAE.

Returns & Warranty

  • 30-Day Guarantee: Returns accepted for in-stock products in original, factory-sealed packaging.
  • 12-Month Warranty: Every industrial component is backed by our professional technical warranty.

Orders are processed and delivered Monday-Friday (excluding public holidays).


For full eligibility, restocking fees, and international return details, please view our official Refund & Return Policy .

TECHNICAL SPECIFICATIONS

Country of origin
Germany

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