Fast and fail-safe industrial communication

The Beckhoff Lightbus system is a fast and fail-safe serial fieldbus system that was conceived for the needs of automation technology. Low-cost and easy-to-process standard fibre optic conductor technology is used for transmission. The crucial advantages of the fibre optic conductor are interference immunity to electromagnetic influences, complete electrical isolation of connected modules from one another and a high data transfer rate. In conjunction with an optimised, compact telegram structure, the Lightbus permits a very high user information data transfer rate of up to 2.5 Mbits/s. With one Lightbus interface board, up to 255 decentralised modules can be operated with a maximum distance of up to 300 m between two modules.

Reliability and flexibility

Reliability is a must – with efficient test and diagnostic functions, functioning of the individual Lightbus modules and communication in the entire Lightbus ring are monitored cyclically and automatically.

Changes or additions to a system configuration can be realised easily and reliably by means of configuration programs in the Lightbus system. The Lightbus system is open and universally applicable. Lightbus interfaces are available for common bus and computer architectures and for control systems in use around the world.

The wide range of distributed Lightbus components covers the requirements found in automation technology for items from displacement sensors, through universal Bus Terminals up to drive controllers.

Easy assembly – high data rate

The Lightbus system, based on standard plastic fibre optics, offers simple assembly and very high data rates combined with total immunity to interference; its simple and efficient bus protocol, using a master/slave principle, is ideal for automation applications.

Communication services for process and parameter data

Services for system operation and data transfer are handled within a simple protocol frame. Intelligent interface cards for all computer architectures offer convenient communication services via logical channels to the modules.

The protocol is implemented in hardware for high-speed communication without delays.

Deterministic behaviour for eight independent channels

Its fast, deterministic behaviour, interrupt signal handling, together with random access to individual components make the Lightbus particularly suitable for control and regulation tasks. Fast communication, such as position control or process functions, can be carried out at the same time as slower communication for the purposes, for instance, of PLC functions.

A process image with 1,280 inputs and outputs is fully read and written within 1 ms. Process signals can be observed with a 25 µs sampling interval at the same time. This functionality allows one to meet all PLC, NC and control requirements with one single fieldbus.