Special acceptance in the semiconductor industry: EtherCAT is SEMI™ standard
Beckhoff launched EtherCAT in 2003. The EtherCAT Technology Group (ETG) was established with the support of 33 founding members, including Applied Materials. Since then the ETG has been dealing with the standardization and maintenance of the technology. With more than 6,000 members, the ETG is now the world's largest industrial fieldbus user organization. In 2005, the Safety over EtherCAT protocol supplemented the EtherCAT specification with the capability to transmit safety-relevant data. The protocol is particularly lean in its implementation, but completely independent of the communication system used (black channel). In 2007, EtherCAT became the IEC standard and the SEMI™ standard. 2011 saw the launch of ETG's Semiconductor Technical Working Group, in which users and manufacturers develop and maintain special device profiles for the semiconductor industry in 11 task groups. This guarantees the openness of the system and demonstrates its high acceptance in the semiconductor industry. To this day, the EtherCAT specification has never been changed, only extended in a compatible manner. This means that today's devices can still be operated in networks dating back to 2003, so there are no versioning problems.
In 2016, the EtherCAT P extension set a further milestone with the transfer of EtherCAT communication and supply voltage (2 x 24 V) on a standard Ethernet cable. This concept became the basis for machines without control cabinets. In 2018, a big step towards higher transfer rates was taken with EtherCAT G/G10. The integration of the existing EtherCAT device range is a main requirement. Among other things, the branch concept was introduced for this purpose.
Exceptional performance
EtherCAT is by far the fastest industrial Ethernet technology. Added to this is the outstanding synchronization accuracy in the order of nanoseconds. Of course, all applications in which control or measurement tasks are performed via the bus benefit from this. Thanks to the significantly reduced response time, all applications in which switching conditions occur are also more efficient. In addition, the EtherCAT system architecture reduces the load on the controller: with the same cycle time, CPU load reductions of 25 to 30 % are typical compared to other bus systems. Used correctly, the EtherCAT performance leads to higher accuracy and higher throughput and thus lower costs.
Flexible topology
With EtherCAT, the system structure determines the network topology, not the bus system. No switches or hubs are required, which means there is no limit with regard to cascading. There are no restrictions in terms of the bus topology with EtherCAT: line, tree, star, and any combination thereof are possible, with almost any number of nodes. Thanks to automatic link detection, nodes and network segments can be disconnected and reconnected during operation, even at another point in the network. For line redundancy, the line is complemented to form a ring. On the master side, in addition to software only a second Ethernet port is required for this purpose; slave devices support redundancy in any case. This also makes it possible to replace devices during operation.
Simple and robust
Configuration, diagnostics and maintenance are significant cost factors. EtherCAT greatly simplifies these tasks: if desired, EtherCAT assigns node addresses automatically, without the need for manual intervention. Low bus load and a peer-to-peer setup maximize electromagnetic compatibility. Any faults are not only reliably detected, but also precisely located. This shortens the time required for troubleshooting. Deviations from the planned layout are immediately detected by means of a target/actual comparison on system startup. The outstanding EtherCAT performance also comes in handy for the configuration: in contrast to other systems, no network tuning is required. And thanks to the large bandwidth, the system can easily cope with additional TCP/IP traffic. Since EtherCAT itself is not TCP/IP-based, there is no need to manage MAC or IP addresses, nor a need for IT experts to handle switch or router configuration.
Integrated safety
Functional safety as an integral part of the network architecture can easily be achieved with Safety over EtherCAT (FSoE). The technology is tried and tested, as evidenced by the fact that TÜV-certified devices have been available since 2005. FSoE meets the requirements of SIL 3 and SEMI™ S2 and is suitable for both centralized and decentralized safety controllers. Thanks to its black channel approach and a particularly compact safety container, FSoE can also be used on other buses. The integrated approach and the lean protocol result in low system costs. Non-safe control systems may “listen in” and evaluate the safety-relevant data.