Beckhoff BC9000 Documentation page 9

Product overview
controller in the control cabinet and the subsidiary terminal boxes. The power sector of the plant is also
controlled over the bus system in addition to the sensor/actuator level. The Bus Terminal replaces the
conventional series terminal as the wiring level in the control cabinet. The control cabinet can have smaller
dimensions.
Bus Couplers for all usual bus systems
The Beckhoff Bus Terminal system unites the advantages of a bus system with the possibilities of the
compact series terminal. Bus Terminals can be driven within all the usual bus systems, thus reducing the
controller parts count. The Bus Terminals then behave like conventional connections for that bus system. All
the performance features of the particular bus system are supported.
Mounting on standardized mounting rails
The installation is standardized thanks to the simple and space-saving mounting on a standardized mounting
rail (EN 60715, 35 mm) and the direct wiring of actuators and sensors, without cross connections between
the terminals. The consistent labelling scheme also contributes.
The small physical size and the great flexibility of the Bus Terminal system allow it to be used wherever a
series terminal is also used. Every type of connection, such as analog, digital, serial or the direct connection
of sensors can be implemented.
Modularity
The modular assembly of the terminal strip with Bus Terminals of various functions limits the number of
unused channels to a maximum of one per function. The presence of two channels in one terminal is the
optimum compromise of unused channels and the cost of each channel. The possibility of electrical isolation
through potential feed terminals also helps to keep the number of unused channels low.
Display of the channel state
The integrated LEDs show the state of the channel at a location close to the sensors and actuators.
K-bus
The K-bus is the data path within a terminal strip. The K-bus is led through from the Bus Coupler through all
the terminals via six contacts on the terminals' side walls. The end terminal terminates the K-bus. The user
does not have to learn anything about the function of the K-bus or about the internal workings of the
terminals and the Bus Coupler. Many software tools that can be supplied make project planning,
configuration and operation easy.
Potential feed terminals for isolated groups
The operating voltage is passed on to following terminals via three power contacts. You can divide the
terminal strip into arbitrary isolated groups by means of potential feed terminals. The potential feed terminals
play no part in the control of the terminals, and can be inserted at any locations within the terminal strip.
Up to 64 Bus Terminals can be used in a terminal block, with optional K-bus extension for up to 256 Bus
Terminals. This count does include potential feed terminals, but not the end terminal.
Bus Couplers for various fieldbus systems
Various Bus Couplers can be used to couple the electronic terminal strip quickly and easily to different
fieldbus systems. It is also possible to convert to another fieldbus system at a later time. The Bus Coupler
performs all the monitoring and control tasks that are necessary for operation of the connected Bus
Terminals. The operation and configuration of the Bus Terminals is carried out exclusively by the Bus
Coupler. Nevertheless, the parameters that have been set are stored in each Bus Terminal, and are retained
in the event of voltage drop-out. Fieldbus, K-bus and I/O level are electrically isolated.
If the exchange of data over the fieldbus is prone to errors or fails for a period of time, register contents (such
as counter states) are retained, digital outputs are cleared, and analog outputs take a value that can be
configured for each output when commissioning. The default setting for analog outputs is 0 V or 0 mA. Digital
BC9000 and BC9100 Version: 4.0.0 9