The Bus Terminal Controllers BC8000 and BC8100 are Bus Couplers with integrated PLC functionality and have a free serial interface. In the case of the BC8000 controller it is an RS485 interface, through which a number of serial devices can be addressed. The BC8100 controller has a RS232 interface, with which peer-to-peer connection is possible. The programmable interface is suitable for the connection of serial devices. The protocol can be freely programmed, so that displays, scanners, measuring systems, BK8x00 or a PC can be connected. The serial interface then functions as a master. A serial terminal, which is removed after the programming, is needed in order to test the interface.

The “Compact” Bus Terminal Controllers BC8050 with serial RS485 interface and BC8150 with serial RS232 interface extend the Beckhoff small controller series by cost-optimised versions 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.