BECKHOFF BK4000 - Manual (Page 5)

Basic information
BK4000 5
Basic information
The Beckhoff bus terminal system
Up to 64 bus terminals
each with 2 I/O channels
for any form of signal
Decentralized wiring of
the I/O level
IPC as control unit
Bus couplers for all current
bus systems
Standard C rail assembly
Modularity
Display of channel status The bus terminal system is the universal connecting link between a field-
bus system and the sensor/actor level. A unit consists of a bus coupler,
which is the interface to the fieldbus, and up to 64 electronic terminals, of
which the last is an end terminal. Terminals, each with two I/O channels,
are available for any form of technical signal and can be combined as desi-
red. The various types of terminal are all constructed in the same way, so
that the planning costs are kept extremely low. The height and depth of the
construction are calculated for compact terminal cabinets.
Fieldbus technology makes it possible to use compact control architectu-
res. The I/O level does not need to be taken right up to the control unit.
Sensors and actors can be connected decentrally with minimal lengths of
cable. You can position the control unit at any convenient location in the
installation. Using an industrial PC as control unit makes it possible to im-
plement the operating and monitoring element as part of the control hard-
ware, so the control unit can be located on an operating desk, control point
or similar. The bus terminals constitute the decentralized input/output level
of the control unit in the switch cabinet and its subordinate terminal cabi-
nets. As well as the sensor/actor level, the power unit of the equipment is
also controlled via the bus system. The bus terminal replaces a conventio-
nal terminal as the cabling level in the switch cabinet; the switch cabinet
can be made smaller.
The Beckhoff bus terminal system combines the advantages of a bus sys-
tem with the functionality of compact terminals. Bus terminals can be used
on all current bus systems and serve to reduce the diversity of parts in the
control unit, while behaving like the conventional standard units for the
relevant bus system and supporting the entire range of functionality of the
bus system.
The simple and compact assembly on a standard C rail, and the direct
cabling of actors and sensors without cross connections between the ter-
minals, serve to standardize the installation, as does the uniformly de-
signed labeling.
The small size and great flexibility of the bus terminal system mean that
you can use it anywhere that you could use a terminal and use any type of
connection – analog, digital, serial or direct sensors.
The modular construction of the terminal row, using bus terminals with
various functions, limits the number of unused channels to at most one per
function. Two channels to a terminal is the optimum solution for the number
of unused channels and the cost per channel. The possibility of using po-
wer input terminals to provide separate power supplies also helps to mini-
mize the number of unused channels.
The integrated light-emitting diodes close to the sensor/actor indicate the
status of each channel.
The K-bus
End terminal
The K-bus is the path taken by data within the terminal row. The bus cou-
pler carries the K-bus through all the terminals by means of six contacts on
the side walls of the terminals, and the end terminal terminates the K-bus.
The user does not need to know anything about the function of the K-bus
or the internal operation of terminals and bus couplers. There are nume-
rous software tools available which provide for convenient planning, confi-
guration and operation.