BECKHOFF BK7000 - Manual (Page 10)

Basic information
9 BK 7000
Mechanical design
The Beckhoff bus terminal system is remarkable for its compact construc-
tion and high degree of modularity. When you design the installation you
will need to plan for one bus coupler and some number of bus terminals.
The dimensions of the bus couplers do not depend on the fieldbus system.
If you use large plugs, for example like some of the bus plugs used for the
Profibus, they may protrude above the overall height of the cabinet.
Dimensions of a
bus coupler
+ +
00 X0
PE PE
B
E
C
K
H
O
F
F
24V 0V
BK
70
00
ControlNet
0 9
8
7
6 5 4
3
2
1
0 9
8
7
6 5 4
3
2
1
x10
x1
A
B
10
0
94
49 12
E0
.0
+ +
00
.1
PE PE
The overall width of the construction is the width of the bus coupler, includ-
ing the bus end terminal, plus the width of the installed bus terminals. The
bus terminals are 12 mm or 24 mm wide, depending on their function. De-
pending on the gauge of cables used the overall height of 68 mm may be
overstepped by about 5 mm to 10 mm by the cables at the front.
Assembly and connections
It takes only a slight pressure to latch the bus coupler and the various bus
terminals onto a supporting 35mm C rail and a locking mechanism then
prevents the individual housings from being removed. You can remove
them without effort if you first release the latching mechanism by pulling the
orange tab. You should carry out work on the bus terminals and the bus
coupler only while they are switched off: if you plug or unplug components
while the power is on you may briefly provoke some undefined state (and,
for instance, reset the bus coupler).
You can attach up to 64 bus terminals in series on the right-hand side of
the bus coupler. When you assemble the components, make sure that you
mount the housings so that each slot comes together with the correspond-
ing key. You cannot make any functional connections merely by pushing
the housings together along the supporting track. When they are correctly
mounted there should be no appreciable gap between the adjacent hous-
ings.
The right-hand side of a bus coupler is mechanically similar to a bus termi-
nal. There are eight connections on the top which can be used to connect
to thick-wire or thin-wire lines. The connection terminals are spring loaded.
You open a spring terminal by applying a slight pressure with a screwdriver
or other pointed tool in the opening above the terminal and you can then
insert the wire into the terminal without any obstruction. When you release
the pressure the terminal will automatically close and hold the wire se-
curely and permanently.