Advantages of Real Time EtherCAT
EtherCAT is a real time and flexible Ethernet protocol that was published as IEC 61158 standard. Real time EtherCAT data exchange follows a “processing on the fly” principal. Meaning that, all data passes through each slave device with minimal delay prior to processing. This feature positions EtherCAT as the ideal Ethernet based industrial control systems solution with numerous distributed I/O and cycle durations of less than 100 µs. Moreover, real time EtherCAT offers significant benefits over competing networking technologies. They include;
Safety: EtherCAT supports black channel safety. In this context, the term black channel is used to mean that the safety network does not appear to be present. Note that, the black channel network in the bus system only serves as a transmission medium that does not perform any safety related duties.
Utilizes simplified masters: master devices issue messages and receive responses through a single message in – single message out protocol. This is easier than using EtherNet/IP Scanner that tracks messages sent out to all slave devices.
Simplified slave devices: slave devices can process TCP data without the need to implement TCP/IP stack. EtherCAT master device can perform TCP/IP processing while the TCP or UDP packet data is passed to slave devices.
Processing on the fly: the processing on the fly concept requires all I/O’s to be processed as messages move through the node from input to output ports. Inputs are added to messages while outputs are taken of the messages.
Huge data space: EtherCAT message telegrams can be as big as 60KB. As such, it is possible to move more data from the node to the master. Note that, there is no limit on the number of nodes an EtherCAT network can hold.
Real time EtherCAT master is a highly effective function library that facilitates the implementation of complex automation tasks. Moreover, its easy usability creates room for high flexibility and low development efforts that guarantee real time functions such as; automatic detection of EtherCAT topology present, fast service and process data communication, PC support as an EtherCAT slave, microsecond reaction durations for I/O data processing, high frequency and accuracy that supports the achievement or hard real time capabilities, command level real time networking of up to 40 Gbit/s, and extendibility with numerous additional functions and protocols like; EoE, FSoE, FoE, and SoE among others.
Summary
Real time EtherCAT has emerged as the most adaptable and fastest Ethernet field bus for industrial use. It is an open function library that facilitates seamless integration of industrial devices into the industrial automation process. It is a cost effective and flexible solution that is also easier to implement.