Fieldbus Components

Beckhoff provides an extensive range of fieldbus components for all common I/O and fieldbus systems. The wide choice of I/O components means that the bus system best suited to the particular application can be chosen:

EtherCAT – Real-time Ethernet: Ultra high-speed right up to the terminal

Outstanding performance, flexible topology and simple configuration characterise EtherCAT (Ethernet for control automation technology), the real-time Ethernet technology from Beckhoff. EtherCAT sets new standards where conventional fieldbus systems reach their limits: 1,000 distributed I/Os in 30 µs, almost unlimited network size, and optimum vertical integration thanks to Ethernet and internet technologies. With EtherCAT, the costly Ethernet star topology can be replaced with a simple line or tree structure – no expensive infrastructure com¬ponents are required. All types of Ethernet devices can be integrated via a switch or switch port.

EtherCAT Terminals

In analogy to the Beckhoff Bus Terminals, the EtherCAT Terminal system is a modular I/O system consisting of electronic terminal blocks. In contrast to Bus Terminals, where the fieldbus signal is implemented within the Bus Coupler on the internal, fieldbus-independent terminal bus, the EtherCAT protocol remains fully intact down to the individual terminal. In addition to EtherCAT Terminals with E-bus connection, the proven standard Bus Terminals with K-bus connection can also be connected via the BK1120 EtherCAT Bus Coupler. This ensures compatibility and continuity with the existing system. Existing and future investments are protected.

EtherCAT Box

The EtherCAT Box modules in protection class IP 67 extend the Beckhoff Fieldbus Box system. Through the integrated EtherCAT interface the modules can be connected directly to an EtherCAT network without an additional Coupler Box. The high EtherCAT performance is therefore maintained right down to each IP 67 box. Each box is a 100 % EtherCAT device and a self-contained EtherCAT slave, which can be connected directly to any other EtherCAT device via an Ethernet cable with 100BASE-TX.

Bus Terminal

The I/O signals are wired in a decentralised way to fieldbus devices or centrally to the controller. The available manufacturer-specific fieldbus devices with fixed input/output configurations and design often make it necessary to use an entire group of devices with similar functions. This costly method of signal acquisition gives rise to high material, installation, planning and documentation costs as well as high costs for subsequent modification or expansion. Inventory management and service staff are put under unnecessary strain.

Fieldbus Box

The Beckhoff Fieldbus Box system is the culmination of the fieldbus concept:
Robust – Robust construction allows fieldbus modules to be fitted directly to machines. Control cabinets and terminal boxes are now no longer required.
Sealed – The modules meet the protection class IP 65, IP 66 and IP 67, are fully casted and thus ideally prepared for use in wet, dirty and dusty working environments.

Lightbus – Simple, low-cost installation

Light up the dark with the Beckhoff Lightbus system by replacing complete cable routes with one single fibre optic conductor. Instead of extensive I/O interfacing units, only one intelligent Beckhoff Lightbus interface board is integrated in the control computer and the decentralised Lightbus modules are directly situated locally. Installation effort and costs are reduced drastically, handling and maintenance are simplified, and interference immunity and performance are increased.
The Lightbus was introduced as far back as 1989 as the Beckhoff system bus for fast machine controllers and has become the market leader in some sectors. These include, for instance, production machines for windows, wood processing machines, presses, packaging machines, machine tools, and applications in metrology and technical building services.

PCI Fieldbus Cards, Switches

PCI Fieldbus Cards – Beckhoff completes its offer of fieldbus components with the PCI-based PC Fieldbus Cards for Lightbus, PROFIBUS, CANopen, DeviceNet, SERCOS interface and Ethernet. The cards have been particularly developed for fast controls and for real-time tasks such as drive position control and can therefore be applied to a wide range of applications. To enable universal application, the interface cards are fitted with either one or two fieldbus channels. The Ethernet variant FC9004 contains four channels altogether. The power of the PC Fieldbus Cards can be most easily seen in combination with the TwinCAT software PLC and NC. But other applications also benefit from the intelligent PCI cards that handle the fieldbus protocol efficiently on their own processors. The process image is available in the DPRAM interface to the PC. Drivers for Windows NT/2000/XP/Vista and Windows 7 and convenient configuration tools are included in the TwinCAT I/O software package. High-level language programs use the DLL, Visual Basic applications the ActiveX interface. Applications with OPC interface can access process data and parameters via an OPC server.

All cards are characterised by concentrated fieldbus know-how in the form of the following features:
– fast data exchange through short cycle times (e.g. EtherCAT: to 50 µs)
– process data communication is either free running, synchronised, synchronised with delay or equidistant
– powerful parameter and diagnostics interfaces
– freely configurable bus management for every device

Mini PCI Fieldbus Cards – New Mini PCI cards for PROFIBUS, CANopen, DeviceNet, SERCOS interface and Ethernet enhance the Beckhoff PC Fieldbus Card range. Like the standard PCI cards from Beckhoff, the interfaces are optimised for fast controllers with small construction volume and real-time tasks.
The new generation of Beckhoff Industrial PCs, including the C69xx control cabinet PCs and the CP62xx/CP66xx Control Panel PCs, are extremely compact. With each device featuring two Ethernet ports, they represent high-performance Industrial PCs for Ethernet and EtherCAT-based control applications. The IPCs can optionally be extended with Mini PCI cards or with fieldbus technology. The bus interface is not implemented on the fieldbus card but separately in the respective housing (device-specific).
Ethernet Switches – The Beckhoff Ethernet Switches offer five, eight or more RJ 45 Ethernet ports. Switches relay incoming Ethernet frames to the destination ports. In full duplex mode, they prevent collisions. They can be used universally in automation and office networks.

CU2508 | Real-time Ethernet port multiplier – The real-time Ethernet port multiplier allows the connection of eight independent Ethernet networks. The CU2508 is connected to the PC via a gigabit uplink. The PC offers high-performance data transfer to the multiplier, which allocates the data to the relevant 100BASE-TX port based on an analysis of a frame prefix and sends them time-controlled with µs precision. Received frames are also allocated a prefix including a timestamp and sent to the PC. With the support of a driver, users have eight independent ports with full real-time characteristics available. The CU2508 is used in applications in which several Ethernet ports are required that need to be realised outside the PC. TwinCAT supports the CU2508 and makes further network ports at the PC unnecessary. For extremely high demands, an EtherCAT installation can, for example, be distributed or expanded to up to eight lines in order to multiply the performance. The distributed clocks of the EtherCAT lines are synchronised. An EtherCAT cable redundancy can also be realised using two ports of the CU2508.


Ethernet is the dominant standard in the office world. The advantages of Ethernet, such as high data transmission rates, easy methods of integration into existing networks, and a wide range of services and interfaces are also found in the Beckhoff Ethernet products.


PROFIBUS is widely used as a fast bus for decentralised peripheral components (PROFIBUS DP). In addition to PROFIBUS DP and FMS, Beckhoff also supports the standard for drive communication, PROFIBUS MC.


PROFINET is the open Industrial Ethernet-standard of the PNO (PROFIBUS Users Organisation). Internationally established IT standards such as TCP/IP are used for communication.


Ethernet/IP is the Industrial Ethernet standard of the ODVA (Open DeviceNet Vendor Association). Ethernet/IP is based on Ethernet TCP/IP and UDP/IP.


The effective utilisation of the bus bandwidth allows CANopen to achieve a short system reaction time at comparatively low data rates. The typical advantages of CAN, such as high data security and multi-master capability are retained.


DeviceNet is a sensor/actuator bus system that originated in the USA, but which meanwhile is increasingly being used in Europe and Asia. DeviceNet is CAN based (Controller Area Net).


Interbus is easy to configure, fast and reliable. The shift register protocol of the master/slave system offers high efficiency in cyclic communication.

SERCOS interface

SERCOS was originally developed as a fast fibre optic bus system for drives. Thanks to the Beckhoff SERCOS Bus Coupler, the advantages such as high data rate and short cycle times can now be provided for the I/O peripherals too.


ControlNet is an open, standardized fieldbus system. The protocol allows both cyclic and acyclic data to be exchanged over the bus without affecting each other.


CC-Link (Control & Communication Link) is an open bus system for communication between the control and fieldbus level. It is predominately used in Asia.


FIP complies with the European standard EN 50170 and receives manufacturer-independent support from the WorldFIP organisation. Through periodic and aperiodic exchange of variables and messages, the performance of the bus can be adjusted to the application.


USB has grown into a standard interface for PC technology. Thanks to its high transmission rate, flexible topology through integrated hubs and the Beckhoff USB Bus Coupler, this system can be used as a substitute for a fieldbus when distances are small.


Modbus is an open, serial communications protocol based on the master/slave architecture. Since it is extremely easy to implement on all kinds of serial interfaces, it has gained wide acceptance.


The “classic” serial interfaces, RS232 and RS485, continue in wide use. The Beckhoff RS485/RS232 I/O modules use a simple, published serial communication protocol that is easy to implement.


AS-Interface connects sensors and actuators with the higher control level via a simple and low-priced wiring method. AS-Interface is internationally standardised through EN 50295 and IEC 62026-2.


IO-Link serves to connect sensors and actuators to the control level by means of an inexpensive point-to-point connection. As an open interface, IO-Link can be integrated in all common fieldbus systems.


The “Digital Addressable Lighting Interface” is a building automation standard for the digital control of electronic ballasts. DALI is used as a subsystem, e.g. for controlling lighting, blinds or temperature, and can communicate directly with the building management system.


EIB (European Installation Bus) is widely and mainly used in Europe as a bus system for cabling in buildings.


LON (Local Operating Network) is a multi-network-capable communication system for distributed applications. It is predominately used for automation applications in commercial buildings.


EnOcean enables the battery-free transmission of switching signals and measured values. The bidirectional EnOcean technology receives signals from battery-less sensors or transmits data to actuators. With a radio signal range of at least 30 m, the wiring of buildings can be simplified significantly.

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