BECKHOFF BK4000 - Manual (Page 7)

Basic information
BK4000 7
The interfaces
There are six ways of making a connection to a bus coupler. These inter-
faces are designed as plug connections and spring terminals.
The InterBus-coupler
BK4000
Power supply
24 V DC on the topmost
terminals “24 V” and “0 V” The bus couplers need an operating power of 24 V DC which is connected
via the topmost spring terminals, labeled “24 V” and “0 V”. This power supply
serves not only the electronic components of the bus coupler but (via the K-
bus) also the bus terminals. The power supply of the bus coupler circuitry
and that of the K-bus are electrically isolated from the voltage of the field
level.
Power supply to the power contacts
Lower 3 terminal pairs for
power input
maximum 24 V
maximum 10 A The six lower connections with spring terminals can be used to supply power
to the peripherals. The spring terminals are connected in pairs to the power
contacts. The power supply to the power contacts has no connection to the
power supply of the bus couplers. The power input is designed to permit
voltages up to 24 V. The pair-wise arrangement and the electrical connection
between the feed terminal contacts makes it possible to loop through the
wires connecting to different terminal points. The load on the power contact
may not continuously exceed 10 A. The current capacity between two spring
terminals is the same as the capacity of the connecting wires.
Power contacts
Spring contacts at the side On the right-hand side face of the bus coupler are three spring contacts
which are the power connections. The spring contacts are recessed in slots
to prevent them from being touched. When a bus terminal is connected, the
blade contacts on the left-hand side of the bus terminal are connected to the
spring contacts. The slot and key guides at the top and bottom of the bus
couplers and bus terminals ensure reliable location of the power contacts.
Field bus connection
9 pin Sub-D female
connector
9 pin Sub-D male connector There is a recessed front surface on the left-hand side. The typical Interbus
connectors can be inserted here. You will find a detailed description of the
field bus interfaces in the Chapter entitled „The medium: connector and
cable“.