BK3520 | PROFIBUS “Economy plus” Bus Coupler, fibre optic

The BK3520 “Economy plus” Bus Coupler links a fibre optic PROFIBUS system to the modular, extendable electronic Bus Terminal system. With the K-bus extension technology up to 255 spatially distributed Bus Terminals can be connected to one Bus Coupler.

The particular feature for the BK3520 Bus Coupler is its fibre optic connection and its high transmission rate of up to 12 Mbaud. The fibre optic link guarantees that the transmission is free from electromagnetic interference and provides full electrical isolation.

An interface-module is necessary to translate between the physical properties of RS485 to those of an underlying optical fibre ring. The topology corresponds with the RS485 physics (line topology). For this reason, the BK3520 possesses two transmitters and two receivers. The address is set by the address selection switch. The baud rate is automatically recognised. Baud rates of up to 12 Mbaud are supported, so that the transmission speed can be adapted to meet the needs of the particular technical process.

The “Economy plus” Bus Coupler has been designed to accommodate automation requirements. PROFIBUS protocols omit FMS operation in order to be able to transfer more user data in DP mode. The BK3520 incorporates the PROFIBUS DP V1 services.

System data	PROFIBUS | BK3520
Number of I/O stations	100 with repeater
Number of I/O points	approx. 6,000, depending on the master
Data transfer medium	APF (plastic) fibre (1,000 µm)
Max. cable length	40 m between two stations
Data transfer rates	up to 12 Mbaud
Data transfer time	approx. 3 ms (10 stations for 32 bit input and output each) approx. 0.5 ms

Technical data	BK3520
Number of Bus Terminals	64 (255 with K-bus extension)
Max. number of bytes fieldbus	128 byte input and 128 byte output
Digital peripheral signals	1,020 inputs/outputs
Analog peripheral signals	64 inputs/outputs
Data transfer rates	automatic detection up to 12 Mbaud
Bus interface	4 x HP-Simplex sockets (HP-Simplex plugs ZS1031-3500 included)
Topology	line topology
Data transfer medium	APF (plastic) fibre (1,000 µm)
Power supply	24 V DC (-15 %/+20 %)
Input current	70 mA + (total K-bus current)/4, 500 mA max.
Current supply K-bus	1750 mA
Power contacts	24 V DC max./10 A max.
Electrical isolation	500 V (power contact/supply voltage/fieldbus)
Distance between stations	40 m
Weight	approx. 170 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
Cordsets	cordsets and connectors
FC310x	PC Fieldbus Cards with PCI interface