BECKHOFF KL6904 - Manual (Page 9)

System description
KL6904 7
2 System description
2.1 The Beckhoff Bus Terminal system
The Beckhoff Bus Terminal system is used for decentralized connection of sensors and actuators to a
control system. The Beckhoff Bus Terminal system components are mainly used in industrial automation
and building management applications. In its minimum configuration, a bus station consists of a Bus
Coupler or a Bus Terminal Controller and Bus Terminals connected to it. The Bus Coupler forms the
communication interface to the higher-level controller, and the terminals are the interface to sensors and
actuators. The whole bus station is clipped onto a 35 mm DIN mounting rail (EN 60715). The mechanical
cross connection of the bus station is established via a slot and key system at the Bus Coupler and the
Bus Terminals.
The sensors and actuators are connected with terminals via the screwless Cage Clamp © connection
system.
Since a wide range of different communication standards are established in industrial automation,
Beckhoff offers Bus Couplers for all common bus systems (e.g. BK3120 for PROFIBUS, BK9000 for
Ethernet, etc.).