Lightbus Bus Coupler BK2020
Power LEDs
K-bus
Bus Coupler
supply
Input for
power contacts
Power contacts
Fieldbus signal input
Fieldbus signal output
Configuration interface

BK2020 | Lightbus Bus Coupler

LightbusThe BK2020 “Economy plus” Bus Coupler connects the Lightbus system to the electronic terminal blocks, which can be expanded in modular fashion. One unit consists of one Bus Coupler, any number of up to 64 terminals and one end terminal. With the K-bus extension technology, the BK2020 allows the connection of up to 255 spatially distributed Bus Terminals to one Bus Coupler. The “Economy plus” series supports all Beckhoff system Bus Terminals. It can process in its full configuration 1020 digital signals and a maximum of 128 analog input and output channels per slave.

The Bus Coupler recognises the connected terminals and automatically generates the affiliations of the inputs/outputs to the bytes of the process image. The first input/output signal is inserted in the first bit of one byte (LSB), beginning from the left. The Bus Coupler inserts further signals in this byte. Inputs and outputs are clearly separated. The Bus Coupler automatically begins a further byte if the number of inputs or outputs exceeds 8 bits.

The Lightbus System is a rapid and safe serial fieldbus system. The Lightbus has a ring structure; up to 254 stations can be operated in a ring. Easy-to-operate standard fibre optic technology is used for data transmission, which represents excellent value. Thanks to an optimised, efficient telegram structure, the Lightbus achieves a very high user data transmission rate. For the exchange of 32 bit information 25 µs transmission time is required.

Thanks to the high-speed access method employed by the Lightbus, it is possible to access specific peripheral data and to read or write the required data only. Data is exchanged with the required priorities without producing any overhead.

System data Lightbus | BK2020
Number of I/O stations 254
Number of I/O points 16,192
Data transfer medium fibre optic conductor: APF (plastic) fibre (1,000 µm) or HCS fibre (200 µm)
Distance between stations 45 m for APF fibre, 300 m HCS fibre
Data transfer rates 2.5 Mbaud
Data transfer time 0.26 ms in the case of 10 modules for 32 bit inputs and outputs each (without K-bus run-time)
Technical data BK2020
Number of Bus Terminals 64 (255 with K-bus extension)
Max. number of bytes fieldbus 512 byte input and 512 byte output
Digital peripheral signals 1,020 inputs/outputs
Analog peripheral signals 128 inputs/outputs
Configuration possibility via KS2000 or the controller
Bus interface 2 x standard fibre optic connector Z1000 (plastic fibre), Z1010 (HCS fibre)
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 24 V DC max./10 A max.
Electrical isolation 500 V (power contact/supply voltage)
Distance between stations 45 m for APF fibre, 300 m HCS fibre
Weight approx. 150 g
Operating/storage temperature 0…+55 °C/-25…+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 CE, UL, Ex
Accessories  
KS2000 configuration software for extended parameterisation
Z1xxx Fibre optics and accessories
FC200x-0000 Lightbus PCI fieldbus cards
C1xxx PC Fieldbus Cards with ISA, VME bus, S5 interface
Related products  
BK2000 Lightbus Bus Coupler for up to 64 Bus Terminals
BK2010 Lightbus Bus Coupler for up to 64 digital Bus Terminals
System  
Lightbus For further Lightbus products please see the system overview