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BECKHOFF BK1120 | EtherCAT Bus Coupler for standard Bus Terminals
BECKHOFF BK1120 | EtherCAT Bus Coupler for standard Bus Terminals

BK1120 | EtherCAT Bus Coupler for standard Bus Terminals. 


The BK1120 EtherCAT Coupler is the link between the EtherCAT protocol at fieldbus level and the Bus Terminals. The coupler converts the passing telegrams from Ethernet 100BASE-TX to the internal, fieldbus-independent terminal bus. A station consists of a coupler and up to 64 Bus Terminals plus a bus end terminal. The process image of the EtherCAT system is assigned automatically. Up to 255 Bus Terminals can be connected via the K-Bus extension.

Special features:

  • Connection technology: 2 x RJ45 socket
  • Connection lengths: up to 100 m
  • connects the EtherCAT protocol with the Bus Terminals

The BK1120 has two RJ45 sockets. The upper Ethernet interface is used to connect the coupler to the network; the lower socket serves for the optional connection of further EtherCAT devices in the same segment.

The system and field supply, each 24 V DC, is provided directly at the coupler. The attached Bus Terminals are supplied with the current required for communication from the supplied system voltage. The field supply is forwarded to the individual I/O components via the power contacts with up to 10 A. In the EtherCAT network, the EK1120 coupler can be installed anywhere in the Ethernet signal transfer section (100BASE-TX) – except directly at the switch. The EK9000 and EK1000 couplers are suitable for use at the switch.

System data EtherCAT | BK1120
Number of I/O stations 65,535
Number of I/O points depending on controller
Data transfer medium Ethernet/EtherCAT Cat.5 cable
Max. cable length 100 m (100BASE-TX)
Data transfer rates 100 Mbit/s
Data transfer time 0.01 ms in the case of 10 modules for 32 bit inputs and outputs each (without K-bus run-time)
Technical data BK1120
Number of Bus Terminals 64 (255 with K-bus extension)
Max. number of bytes fieldbus 1024 byte input and 1024 byte output
Configuration possibility via KS2000 or EtherCAT (ADS)
Bus interface 2 x RJ45
Power supply 24 V DC (-15 %/+20 %)
Input current 70 mA + (total K-bus current)/4, 500 mA max.
Starting current approx. 2.5 x continuous current
Recommended fuse ≤ 10 A
Current supply K-bus 1750 mA
Power contacts max. 24 V DC/max. 10 A
Electrical isolation 500 V (power contact/supply voltage/Ethernet)
Distance between stations 100 m (100BASE-TX)
Weight approx. 150 g
Operating/storage temperature -25…+60 °C/-40…+85 °C
Relative humidity 95 %, no condensation
Vibration/shock resistance conforms to EN 60068-2-6/EN 60068-2-27
EMC immunity/emission conforms to EN 61000-6-2/EN 61000-6-4
Protect. class/installation pos. IP 20/variable
Approvals/markings CE, UL, ATEX
Ex marking II 3 G Ex nA IIC T4 Gc