Q:Information: - EtherCAT - Ethernet for Control Automation Technology - is an Ethernet-based fieldbus system, invented by Beckhoff Automation. The protocol is standardized in IEC 61158 and is suitable for both hard and soft real-time requirements in automation technology. - In the IEEE 802 reference model of computer networking, the medium access control or media access control (MAC) layer is the lower sublayer of the data link layer (layer 2) of the seven-layer OSI model. The MAC sublayer provides addressing and channel access control mechanisms that make it possible for several terminals or network nodes to communicate within a multiple access network that incorporates a shared medium, e.g. an Ethernet network. The hardware that implements the MAC is referred to as a "media access controller". - A technical standard is an established norm or requirement in regard to technical systems. It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes and practices. In contrast, a custom, convention, company product, corporate standard, and so forth that becomes generally accepted and dominant is often called a "de facto" standard. - Industrial Ethernet (IE) is the use of Ethernet in an industrial environment with protocols that provide determinism and real-time control. Protocols for Industrial Ethernet include EtherCAT, EtherNet/IP, PROFINET, POWERLINK, SERCOS III, CC-Link IE, Modbus/TCP. Many Industrial Ethernet protocols use a modified MAC (Media Access Control) layer to provide low latency and determinism . Some microcontrollers such as Sitara provide Industrial Ethernet support. - Sercos III is the third generation of the Sercos interface, a globally standardized open digital interface for the communication between industrial controls, motion devices, input/output devices (I/O), and Standard Ethernet nodes. Sercos III merges the hard real-time aspects of the Sercos interface with Ethernet. It is based upon and conforms to the Ethernet standard (IEEE 802.3 & ISO/IEC 8802-3). Work began on Sercos III in 2003, with vendors releasing first products supporting it in 2005. In addition to the standard Sercos features cited under the Sercos interface general description, Sercos III also provides: - PROFINET (pitch acronym for Process Field Net) is an industry technical standard for data communication over Industrial Ethernet, designed for collecting data from, and controlling, equipment in industrial systems, with a particular strength in delivering data under tight time constraints (on the order of 1ms or less). The standard is maintained and supported by , an umbrella organization headquartered in Karlsruhe, Germany. - Karlsruhe (formerly Carlsruhe) is the second-largest city in the state of Baden-Wurttemberg, in southwest Germany, near the French-German border. It has a population of 307,755. The city is the seat of the two highest courts in Germany: the Federal Constitutional Court and the Federal Court of Justice. Its most remarkable building is Karlsruhe Palace, which was built in 1715. - EtherNet/IP is an industrial network protocol that adapts the Common Industrial Protocol to standard Ethernet. EtherNet/IP is one of the leading industrial protocols in the United States and is widely used in a range industries including factory, hybrid and process. The EtherNet/IP and CIP technologies are managed by ODVA, Inc., a global trade and standards development organization founded in 1995 with over 300 corporate members. - Fieldbus is the name of a family of industrial computer network protocols used for real-time distributed control, standardized as IEC 61158. - A computer network or data network is a telecommunications network which allows nodes to share resources. In computer networks, networked computing devices exchange data with each other using a data link. The connections between nodes are established using either cable media or wireless media. The best-known computer network is the Internet. - Berlin is the capital and the largest city of Germany as well as one of its constituent 16 states. With a population of approximately 3.5 million people, Berlin is the second most populous city proper and the seventh most populous urban area in the European Union. Located in northeastern Germany on the banks of rivers Spree and Havel, it is the centre of the Berlin-Brandenburg Metropolitan Region, which has about 6 million residents from more than 180 nations. Due to its location in the European Plain, Berlin is influenced by a temperate seasonal climate. Around one-third of the city's area is composed of forests, parks, gardens, rivers and lakes. - PROFIBUS ( Process Field Bus ) is a standard for fieldbus communication in automation technology and was first promoted in 1989 by BMBF ( German department of education and research ) and then used by Siemens . It should not be confused with the PROFINET standard for Industrial Ethernet . PROFIBUS is openly published as part of IEC 61158 . - An acronym is a word or name formed as an abbreviation from the initial components in a phrase or a word, usually individual letters (as in "NATO" or "laser") and sometimes syllables (as in "Benelux"). - Modbus is a serial communications protocol originally published by Modicon (now Schneider Electric) in 1979 for use with its programmable logic controllers (PLCs). Simple and robust, it has since become a "de facto" standard communication protocol, and it is now a commonly available means of connecting industrial electronic devices. The main reasons for the use of Modbus in the industrial environment are: - A control system manages, commands, directs or regulates the behaviour of other devices or systems. It can range from a home heating controller using a thermostat controlling a domestic boiler to large Industrial control systems which are used for controlling processes or machines. - Siemens AG is a German conglomerate company headquartered in Berlin and Munich and the largest manufacturing and electronics company in Europe with branch offices abroad. - Automation or automatic control, is the use of various control systems for operating equipment such as machinery, processes in factories, boilers and heat treating ovens, switching on telephone networks, steering and stabilization of ships, aircraft and other applications and vehicles with minimal or reduced human intervention. Some processes have been completely automated. - Munich (also in British English ) is the capital and largest city of the German state of Bavaria, on the banks of River Isar north of the Bavarian Alps. Munich is the third largest city in Germany, after Berlin and Hamburg, and the 12th biggest city of the European Union, with a population of above 1.5million. The Munich Metropolitan Region is home to 5.8million people. - Ethernet is a family of computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3, and has since been refined to support higher bit rates and longer link distances. Over time, Ethernet has largely replaced competing wired LAN technologies such as token ring, FDDI and ARCNET. Given the information, choose the subject and object entities that have the relation of 'instance of'.
A:
profibus , communications protocol