RS232 Bus Terminal Controllers BC8150
Status display
power LEDs
Bus Coupler
Input for
power contacts
Power contacts
Serial interface
Address selector
Configuration and
programming interface
Address selector
extended temperature range

BC8150 | RS232 Bus Terminal Controllers

The BC8150 “Compact” Bus Terminal Controller with serial RS232 interface extends the Beckhoff small controller series by a cost-optimized version in a compact housing. An open serial protocol – like in the BK8x00 Bus Couplers – and the Modbus RTU/ASCII protocol are implemented. The address and the protocol are selected via the two rotary selection switches.

Controller for stand-alone applications

The Bus Terminal Controller is programmed using the TwinCAT programming system conforms to IEC 61131-3. The PLC programs can be written in five different programming languages (IL, FBD, LD, SFC, ST). In addition, TwinCAT offers extensive debug functionalities (breakpoint, single step, monitoring, …), which facilitate commissioning. It is also possible to perform adjustment and measurement of the cycle time. The inputs and outputs of the connected Bus Terminals are assigned in the PLC.

Data is exchanged with the interface on the Bus Terminal Controller with the aid of a control and status byte, through which a handshake must be executed. A serial communication function block for TwinCAT is available for this purpose.

PLC data RS232 | BC8150
Programming TwinCAT (via programming interface or fieldbus)
Program memory 48 kbytes
Data memory 32 kbytes
Remanent data 2 kbytes
Runtime system 1 PLC task
PLC cycle time approx. 3 ms for 1,000 instructions (without I/O cycle, K-bus)
Programming languages IEC 61131-3 (IL, LD, FBD, SFC, ST)
Online change yes
Technical data BC8150
Number of Bus Terminals 64 (255 with K-bus extension)
Max. number of bytes fieldbus 512 byte input and 512 byte output
Max. number of bytes process image 512 byte input and 512 byte output
Digital peripheral signals 1,020 inputs/outputs
Analog peripheral signals 128 inputs/outputs
Protocol KS8000 protocol (open, serial protocol) – Modbus RTU/Modbus ASCII can be selected via address switch, serial ADS.
Data transfer rates 1.2 kbaud…38.4 kbaud
Bus interface RS232 D-sub
Power supply 24 V DC (-15 %/+20 %)
Input current 320 mA max.
Starting current 2.5 x continuous current
Current supply K-bus 1750 mA
Power contacts max. 24 V DC/max. 10 A
Electrical isolation 500 V (power contact/supply voltage)
Weight approx. 100 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
Accessories/related products  
KS2000 configuration software for extended parameterisation
TX1200 programming system conforms to IEC 61131-3
TS6340 IEC 61131-3 software library for TwinCAT PLC for communication via serial devices
KL6001 Bus Terminals, serial interface RS232
KL6021 Bus Terminals, serial interface RS422/RS485
Cordsets cordsets and connectors
BC8050 RS485 “Compact“ Bus Terminal Controller for up to 64 Bus Terminals (255 with K-bus extension)
BX8000 RS232/RS485 Bus Terminal Controller for up to 64 Bus Terminals (255 with K-bus extension)
BK8000 RS485 Bus Coupler for up to 64 Bus Terminals
BK8100 RS232 Bus Coupler for up to 64 Bus Terminals
RS485 For further RS485 products please see the system overview