System overview Modbus

Modbus is an open, serial communication protocol based on the master/slave architecture. Since it is very simple to implement on serial interfaces (Modbus ASCII and Modbus RTU) or the TCP/IP protocol stack (Modbus TCP), it is very widely used. All variants have a uniform protocol in common, which specifies a universal object model for automation-related technical data and communication services for access.

TwinCAT

Industrial PC/
Embedded PC

Bus Terminals

EtherCAT
Terminals

Fieldbus Box

TwinCAT I/O
– TwinCAT System Manager
Supplement “TwinCAT TCP/IP Server”: server and PLC library for communication
via generic TCP servers
Supplement “TwinCAT PLC Modbus RTU”: TwinCAT as Modbus RTU master
Supplement “TwinCAT Modbus TCP Server”: TwinCAT as Modbus TCP master

Modbus master:
IPC

Modbus master:
Embedded PC CX8090 with Modbus TCP protocol implementation

Modbus slave:
Bus Coupler BK73x0,
Bus Terminals

Modbus slave:
Bus Terminal Controller
BC7300 (IEC 61131-3),
Bus Terminals

Modbus slave:
Bus Terminal Controller BC8050/BC8150 (IEC 61131-3)
with Modbus RTU protocol implementation, Bus Terminals

IP-Link

Modbus slave:
Compact Box IPxxxx-B730

Modbus slave:
Coupler Box IL230x-B730 with Extension Box IExxxx