Beckhoff BC7300 Manual page 8

Basic Principles
Display of the channel state
K-Bus
End terminal
Potential feed terminals for
galvanically isolated groups
The principle of the
Bus Terminal
Additional characteristics of
the Bus Terminal
Controllers
Bus Terminal Controllers
for various fieldbus systems
BC7300
to keep the number of unused channels low.
The integrated LEDs show the state of each channel at a location close to
the sensors and actuators.
The K-Bus is the data path within a terminal strip.
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.
The operating voltage is passed on to following terminals via three power
contacts. You can divide the terminal strip into arbitrary galvanically
isolated groups by means of potential feed terminals. The feed terminals
play no part in the control of the terminals, and can be inserted at any
points within the terminal strip.
Up to 64 terminals may be located in a terminal strip, including the potential
feed terminals and end terminal.
Bus Coupler
power
Bus Coupler
supply
BC7300
01 02
MODBUS
WD
RX
0V
24V
TX
PLC
+ +
0
PE PE
0
Power
contacts
Bus Terminal Controllers (BC) differ from Bus Couplers (BK) in that, in
addition to K-Bus processing, a real-time PLC task is also running. Unlike
Bus Couplers, the signals from the terminals are processed by the PLC
task, while the fieldbus carries the in- and outputs of the PLC task. It is
possible, however, to subdivide the Bus Terminals to that some Bus
Terminals are pre-processed by the PLC task, while others are sent
directly over the fieldbus to a supervising system.
Various Bus Terminal Controllers can be used to couple the electronic
terminal strip with integrated PLC task quickly and easily to different
fieldbus systems. It is also possible to convert to another fieldbus system at
a later time. The Bus Terminal Controller 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 Terminal Controller. Fieldbus, K-Bus and I/O
level are galvanically isolated.
The K-Bus is led
Potential
input
terminal
K-Bus
Potential
isolation
End Terminal
8