The Ethernet Fieldbus 2 Contents a Bus System Might Not Be Everything … 3
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EtherCAT – the Ethernet Fieldbus 2 Contents A bus system might not be everything … 3 3 A bus system might not be everything … … but the machine is nothing without it! standard. This brochure also introduces Not only is it a central part of the system the EtherCAT Technology Group (ETG), 4 EtherCAT at a glance architecture, but its performance also the world’s largest fieldbus organization. determines whether the entire system is Most importantly, we hope to convey why 6 EtherCAT Technology Group able to reach its full performance. The bus EtherCAT is the right choice for your ap- system is also a key factor in determining plication. If you have any questions, feel 8 Why use EtherCAT? system costs, commissioning time, and free to contact us. We’re passionate about robustness. That’s why a good engineer EtherCAT and look forward to hearing 10 The Technology in Detail selects the right bus technology as the from you. 10 EtherCAT: Based on Ethernet Technology first step to system design. 11 How does EtherCAT work? We’ve written this brochure to in- 12 The EtherCAT Protocol troduce you to EtherCAT, the “Ethernet On behalf of the 14 Flexible Topology fieldbus”. Not only will you get to know EtherCAT Technology Group Team, 16 Distributed Clocks for High-Precision Synchronization EtherCAT – you will also learn what makes Martin Rostan, Executive Director, 18 Diagnostics and Error Localization EtherCAT the fastest Industrial Ethernet EtherCAT Technology Group 19 High Availability Requirements 20 System Overview 22 Safe Data Transfer with Safety over EtherCAT 24 Communication Profiles 26 Plant-wide communication with the EtherCAT Automation Protocol (EAP) 29 Integration of other Bus Systems 30 Implementing EtherCAT Interfaces 32 Implementing a Master Device 34 Implementing a Slave Device 36 Conformance and Certification 39 Contact Martin Rostan, Executive Director, The worldwide ETG Team EtherCAT Technology Group at a Global Strategy Meeting. 4 EtherCAT at a glance 5 EtherCAT is a high-performance, low-cost, Flexible Topology It’s low-cost Open Technology easy to use Industrial Ethernet technology with a flexible topology. It was introduced In addition it its speed, an EtherCAT net- EtherCAT delivers all of the advantages of EtherCAT is an internationally standard- in 2003 and has been an international work can support up to 65,535 devices Industrial Ethernet at fieldbus prices. How? ized open technology, meaning anyone is standard since 2007. The EtherCAT Tech- without placing restrictions on their topol- Firstly, EtherCAT doesn’t require any active free to use the technology in a compatible nology Group promotes EtherCAT and is ogy: line, bus, tree, star – or any combina- infrastructure components. The master form. However, being an open technology responsible for its continued development. tion thereof. Fast Ethernet Physics allows device doesn’t require a special interface doesn’t mean that anyone can arbitrarily EtherCAT is also an open technology: any- two devices to be up to 100m (330 ft.) card and the slave devices use highly-inte- change EtherCAT to suit his or her needs. one is allowed to implement or use it. apart, and greater distances are possible grated, cost-effective chips available from This would be the end of interoperabil- with the use of fiber optics. EtherCAT also a variety of suppliers. Additionally, there’s ity. The EtherCAT Technology Group, the has additional features that offer further no need for costly IT experts to commission world’s largest fieldbus organization, is How it works topological flexibility, such as Hot Connect or maintain the system. responsible for the further development and Hot Swap for devices, and added of EtherCAT so it remains both open and EtherCAT’s key functional principle lies in redundancy through a ring topology. interoperable. how its nodes process Ethernet frames: Industrial Ethernet each node reads the data addressed to it and writes its data back to the frame all It’s versatile EtherCAT also supports common internet It’s proven in use while the frame is moving downstream. technologies without jeopardizing the net- This leads to improved bandwidth utiliza- EtherCAT is suitable for both centralized work’s real-time capability. Its “Ethernet EtherCAT is currently in use across the tion (one frame per cycle is often sufficient and decentralized system architectures. over EtherCAT” protocol transports FTP, globe in an unrivaled range of applica- for communication) while also eliminating It can support master-slave, master- http, TCP/IP and Co. tions. EtherCAT is used in machine control, the need for switches or hubs. master, and slave-slave communication as measurement equipment, medical devices, well as incorporate subordinate fieldbuses. automobiles and mobile machines, as well At the factory-level, the EtherCAT Automa- Functional Safety as in innumerable embedded systems. Network Performance tion Protocol has communication covered – all with the existing infrastructure. “Safety over EtherCAT” is just like EtherCAT The unique way EtherCAT process frames itself – lean and fast. Functional safety is makes it the fastest Industrial Ethernet built directly into the bus with options for Technology; no other technology can top It’s easy both centralized and decentralized safety EtherCAT’s bandwidth utilization or the logic. Thanks to the “Black-Channel” ap- corresponding performance. When compared to a classic fieldbus sys- proach, it is also available for other bus tem, EtherCAT is the obvious choice: node systems. addresses can be set automatically, there’s no need for network tuning, and onboard diagnostics with fault localization make pinpointing errors a snap. Despite these advanced features, EtherCAT is also easier to use than Industrial Ethernet: there are no switches to configure, and no compli- cated handling of MAC or IP addresses is required. 6 EtherCAT Technology Group 7 The EtherCAT Technology Group keeps The ETG has the largest number of mem- International standardization Global Activities EtherCAT technology open for all potential bers out of any fieldbus organization in the users. It brings EtherCAT device manufac- world. The list of members can be found on The EtherCAT Technology Group is an of- The EtherCAT Technology Group is active turers, technology providers, and users its homepage. However, the decisive factor ficial partner of the IEC. Both EtherCAT and worldwide. Experts in the ETG offices in together to further the technology. It pro- is not how many members there are, but Safety over EtherCAT are IEC-Standards Germany, China, Japan, Korea, and the USA vides multiple Technical Working Groups how active the members are in the ETG. (IEC 61158 and IEC 61784). These stand- support ETG members before, during and where experts carefully work on various Both the number and variety of EtherCAT ards not only include the lower protocol after implementation. specific aspects of EtherCAT. All of these devices is unparalleled, and EtherCAT’s layers, but also the application layer and The technology is maintained in the activities are focused on one common goal: adoption rate across Europe, Asia, and device profiles, e.g. for drives. SEMI™ Technical Working Groups (TWG), which keeping EtherCAT stable and interoperable. America surpasses that of all other Indus- (Semiconductor Equipment and Materials define enhancements and also uniform That’s why there is only a single version of trial Ethernet technologies. International) has accepted EtherCAT as a device behavior by means of device profiles EtherCAT, and not a new version each year. communication standard (E54.20) for the and implementation guidelines. All mem- The ETG holds multiple Plug Fests in semiconductor industry. The various Task bers are encouraged to contribute actively ETG Trade Show Booths present Europe, Asia, and America each year. The Become a member Groups in the ETG Semiconductor Techni- to the TWGs. In many countries EtherCAT also is a national standard, such as in Korea. the technology itself as well as the Plug Fests bring EtherCAT device develop- cal Working Group (TWG) define industry EtherCAT product variety. ers together to test and ensure device ETG membership is open to all companies, specific device profiles and implementa- interoperability. Using the official EtherCAT whether device manufacturers or users. tion guidelines. Conformance Test Tool, each manufacturer ETG members: The EtherCAT Specification is available conformance tests its EtherCAT devices Receive access to technical specifica- in English, Japanese, Korean, and Chinese. prior to their release. The ETG awards the tions and the developer’s forum manufacturer a Conformance Certificate Contribute to the further development following a successful test in an accredited of EtherCAT in the way of Technical test lab. Working Groups EtherCAT Milestones The ETG also holds international Receive implementation support from seminars and workshops and represents their local ETG office EtherCAT at tradeshows throughout the Receive free software stacks, globe. It also provides product guides, joint software tools, and access to additional 2003 2005 2006 2007 2008 2009 2011 2012 tradeshow booths, and seminar exhibits development products EtherCAT Safety over 1. EtherCAT EtherCAT is EtherCAT Member 1000 EtherCAT Semiconductor to help its members market their EtherCAT Are permitted to use the EtherCAT introduced EtherCAT ASIC IEC Standard Conformance Test Centers interface Industry Profi les ETG holds regional member products. and ETG logos ETG