High speed, simple twisted-pair wiring, availability of industrial hubs/switches, development of appropriate application protocols – all these factors extend the range of applications for Industrial Ethernet and make it suitable for the sensor/actuator level, i. e. the typical application area of Beckhoff fieldbus components.
The application of Ethernet as a sensor/actuator bus is of particular interest where an Ethernet infrastructure already exists or is planned – for example in applications using PC-based control technology or in building automation.
The Ethernet Fieldbus Box supports 10 Mbit/s and 100 Mbit/s Ethernet. The Ethernet connection is established via encapsulated RJ45 connectors (-B900/-C900) or via a D-coded M12 connector (-B901). The IP address is set via a rotary switch (offset to a freely selectable start address). In networks with DHCP (a service for the allocation of the logical IP address to the physical node address [MAC-ID]) the Fieldbus Box obtains its IP address from the DHCP server.
The Fieldbus Box modules for Ethernet support ADS TwinCAT system communication and real-time Ethernet. TwinCAT I/O makes available configuration tools and Windows/2000/XP drivers for programs in any desired high-level language (DLLs) and for Visual Basic applications (ActiveX). Applications with OPC interfaces can access ADS, and therefore the Ethernet Fieldbus Box, via an OPC server. In addition to ADS, the modules support Modbus (Modbus TCP), a simple, widely used master/slave protocol based on TCP/IP and real-time Ethernet.
The IP address and other Ethernet parameters are set via two rotary selection switches. Special I/O parameters, for example the type of thermocouple that is used, can be set via KS2000.
The extensive diagnostic functions of the Beckhoff devices allow rapid fault localization. Diagnostic messages are transmitted via Ethernet and collected by the master. LEDs on the module indicate the status of the network connection, the device status, the status of the inputs and outputs and of the power supply.
The Ethernet Coupler Box gathers the I/O data from the Extension Box modules over the interference-free IP-Link optical fibre cable. It detects the connected modules and automatically allocates the input and output data to the process image. The Coupler Box has four digital inputs and four digital outputs; all other signal types are available in the form of an Extension Box.
The PLC Box is an intelligent Ethernet node that can perform decentralised processing of I/O data and execute control tasks independently of the function of the Ethernet network. The PLC Box, like the Coupler Box, has four digital inputs and four digital outputs. Up to 120 further Extension Box modules can be connected via IP-Link. The PLC Box is programmed using TwinCAT over Ethernet or through the configuration interface.