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International electrotechnical commission
International Electrotechnical Commission 3 rue de Varembe, Geneva, Switzerland
The IEC, the International Electrotechnical Commission, is the authority for world standards in electrical and electronics engineering. The IEC is composed of National Committees in 43 countries formed to represent in international discussions all their national electrical and electronics interests, including manufacturers, users, trade associations, the engineering profession and government. IEC standards are widely used and accepted because they are developed by experts drawn from a wide spectrum of engineering and scientific knowledgemanufacturers, users, universities, government departments, research, development and test laboratories. Their close proximity to these diverse sources of information places them in a unique position to assess the implications for anyone involved in the design, manufacture and use of equipment.
The IEC in Information Technology The Information Technology 'IT' field is the most rapidly expanding area of electrotechnology in which the IEC works. Although technological advances are giving Information Technology a more prominent role in the IEC today, the IEC has been working in this field since its early days, defining the characteristics, compatibility and interchangeability of electronic components and assemblies which in turn become parts of still larger systems. While technology has in recent years advanced from single to multifunction components, with dimensions going from macro to micro, signals from analogue to digital, and speeds from seconds to less than nanoseconds, the philosophy and principles underlying the IEC's work, however, remain the same: defining the characteristics, and ensuring compatibility and interchangeability of 170
components and assemblies at all stages so that they can be built into complete systems. To meet the needs of users of this continually evolving technology, the IEC has expanded the number of its Technical Committees working in the electronics and telecommunications field to cover a wide range of components, measurement and control devices, telecommunications and electronic equipment. As early as 1955 the IEC's work in the electronics and telecommunications field had expanded to such an extent that a special management body, the Advisory Committee on Electronics and Telecommunications (ACET), was set up to 10ok after the interests of this dynamic sector. During a meeting held in Montreux in June 1981, the Committee of Action of the IEC created a group whose brief is to co-ordinate IEC work in information technology with that of other international bodies, primarily CCIR (International Radio Consultative Committee), CCITT (International Telephone and Telegraph Consultative Committee) and ISO (International Organization for Standardization), and to co-ordinate work in this field within the IEC to ensure that there are neither overlaps nor gaps. To date, this group has achieved a great deal. One of its first actions was to recommend the creation of a new Technical Committee to be responsible for information technology equipment. This recommendation was endorsed by the IEC Council at its meeting in Rio de Janeiro in June 1982, and subsequently, TC 83: Information Technology Equipment, held its first meeting in Wiesbaden in April 1983. ISO/TC 97 and IEC/TC 83 have made special arrangements for collaboration to ensure efficient co-ordination. This means, for example, that these Technical Committees are now mutually represented at each other's meetings. The IEC actively co-operates with organizations such as CCITT and CCIR,
where co-operation dates back to 1927 and 1933 respectively, and with the ISO, in identifying areas where co-ordination is needed and making sure that agreed-upon international standards remain aligned. To speed up the availability of IT standards, the IEC may now issue as IEC standards those of recognized organizations whose texts are in conformity with IEC requirements. The IEC's long experience in component and systems technology, together with the co-ordination the Advisory Committee on Electronics and Telecommunications (ACET) and the Information Technology Co-ordinating Group (ITCG) bring to a complex area, leave it well placed to serve its users in this expanding field.
IEC's History The IEC's work in electronics and telecommunications started in the 1930's in the field of radiocommunications with single-function components for radios-resistors, capacitors, electronic tubes, cables and connectors--the technology that brought radio and television to millions of homes. Like systems in other areas of the IEC's work, these systems required compatibility at all stages. The transfer of the radio signal or television image from the studio through the earth transmitting station or communications satellite to the listener or viewer, demands the proper co-ordinated functioning of tens of thousands of components and assemblies all requiring international standards to work together. The invention of the transistor followed by the growth of microelectronics, and then digital microelectronics, called for IEC standards for a new wave of multifunction components--the semiconductor devices and integrated circuits, the building blocks of the Information Technology society. These miniaturized components made it possible to adopt digital technology as the quickest, most reliable and cost-efficient means of transmitting information. They also made it possible to put increasing amounts of intelligence into many kinds of equipment. These capabilities demanded new requirements from the IEC to ensure that the interface condi-tions of these components within the various systems were met.
At the same time rapid expansion of the home entertainment industry saw the IEC move into sound recording and reproduction and video systems, producing standards for records, digital optical recording disks, audio and video cassettes, microphones and loudspeakers. In industry, the move to automation produced demands for IEC standards for electrical and electronic equipment for industrial machines. The introduction of control systems into industrial processes saw IEC standards developed for analogue systems, and with the introduction of digital techniques, for digital data communications systems as well. The development of new techniques in the power electronics industry, brought about by powerful new semiconductor value devices, and the introduction of large numbers of integrated circuits, has seen the IEC continually updating standards in the power electronics field to provide standards when needed. The increasing use of nuclear power, together with stringent safety requirements, has resulted in more than 100 IEC standards in the fields of nuclear and reactor instrumentation and radiation protection instrumentation. To keep pace with the rapid developments in the data processing field, IEC produced standards covering the safety of this equipment. Because of the introduction of laser techniques in a variety of equipment, the IEC has produced the first world-wide safety standards for the radiation safety of laser products and a standard covering the electrical safety of laser equipment and installations. In the field of fibre optics, which has opened up new dimensions in information transmission, the IEC has produced the first world standards for optical fibres and optical fibre cables. Work is underway within the IEC on rapidly developing more standards for this field. The IEC is also co-operating with the CCITT in this area. To promote common understanding among engineers and scientists in the electronics and telecommunications field, the IEC has published a vocabulary in nine languages, the International Electrotechnical Vocabulary (IEV) which includes terms and definitions for electronics, radiocommunications, space radiocommunications, telegraphy and telephony, electroacoustics, nuclear in-
strumentation, power electronics, automatic control and the recording and reproduction of sound and video. A wide range of graphical symbols suitable for computer-aided design have also been produced for discrete and integrated, analogue and digital components. Work on reliability of electronic components and equipment, closely linked with the complex electronic systems found in IT equipment, has resulted in a number of standards for reliability and maintainability. The IEC has also developed standard methods of test and measurement and set down requirements for measuring instruments, allowing the characteristics of components and equipment offered for sale internationally to be measured by the same tests.
gather, process, transfer and exchange it means that this equipment must be able to interconnect as part of a system, and communicate using the same protocols or rules. IEC work here ranges from buses to link microprocessors, buses to interconnect instruments, and buses for complete industrial process control systems. Here work is nearing completion on two microprocessor systems buses which will allow data transfer between a variety of microprocessors. At the instrument level a standard for an interface system for programmable measuring instruments has been issued.
System Applications
The IEC is producing standards for semiconductor devices, integrated circuits and microprocessor systems, the basic elements of Information Technology systems. Because developments in this field are so rapid, standardization covers the minimum number of characteristics to be specified for interface conditions, including the exchange of data between these components and the systems in which they are used. IEC standards exist for analogue and digital integrated circuits, microprocessors and discrete devices, r IEC standards have also been developed for electroni~ tubes, such as cathode ray tubes; capacitors and resistors, including miniaturized types which allow a very high component density; all types of low frequency cables, coaxial cables and radio frequency connectors; electromechanical components including low frequency connectors, switches, racks and panels; piezoelectric devices for frequency control and selection; magentlc components and ferrite materials used in telecommunications; printed boards and flexible printed circuits; and lithium cells used for back-up power supplies for memory retention.
To accelerate the work, and to serve the growing and changing needs of industries and users which have been created by Information Technology, the IEC has adopted a systems approach to IT standards and is co-operating closely with the CCITT and the CCIR. The approach enables development of standards for entire systems as well as for specific components or pieces of equipment. It also allows manufacturers to design systems and then the equipment to fit into them, rather than designing ways for existing products to fit together, although the latter case still happens. The IEC is now working on standards for one home electronics bus, or channel for transmission signals, to interconnect all electronic equipment in the home. Methods by which this bus will fit into the CCITT's Integrated Services Digital Network (ISDN) are being followed closely by the IEC.
Transmission, Installation and Distribution The trend towards incorporation of the computing function into a wide variety of equipment, not only decentralized data processing, personal computers and word processors, but also a host of other appliances, has magnified the need for interconnection and communication between equipment. To have access to information, to
Components
Safety Safety of equipment and total systems for Information Technology users is a major priority in the creation of IEC international standards. A basic safety standard exists for mains-operated electronic equipment, 171
such as radios and television receivers, amplifiers, record players and recorders, used in the home and similar locations. Sophisticated electromedical equipment, already covered by IEC standards, is now increasingly combined with computers and electronic measuring devices. The IEC will study requirements for the safety of this combined equipment. The IEC is cooperating with the CCITT in producing guidelines covering the safety aspects of equipment connected to telecommunications networks.
Software The IEC has prepared software standards for certain electronic systems.
172
These are based on ISO standards which cover basic aspects of software, and there is continuing co-operation between the ISO and the IEC.
Electromagnetic Compatibility The problem of interference in equipment caused by electromagnetic signals or disturbances has resulted in a number of IEC standards. Under the auspices of the IEC, the International Special Committee on Radio Interference (CISPR) has produced standards dealing with interference caused by industrial, scientific and medical radiofrequency equipment, sound and televi-
sion receivers and household electrical appliances. Without the work of the CISPR, sound broadcasting would not have developed as it did in the 1930's, paving the way for the modern electronic age. Work is now underway within CISPR on a standard which describes the limits of interference and measuring methods for IT equipment.
The IEC, the International Electrotechnical Commission, is the authority for world standards in electrical and electronics engineering. The IEC is composed of National Committees in 43 countries formed to represent in international discussions all their national electrical and electronics interests, including manufacturers, users, trade associations, the engineering profession and government. IEC standards are widely used and accepted because they are developed by experts drawn from a wide spectrum of engineering and scientific knowledgemanufacturers, users, universities, government departments, research, development and test laboratories. Their close proximity to these diverse sources of information places them in a unique position to assess the implications for anyone involved in the design, manufacture and use of equipment.
The IEC in Information Technology The Information Technology 'IT' field is the most rapidly expanding area of electrotechnology in which the IEC works. Although technological advances are giving Information Technology a more prominent role in the IEC today, the IEC has been working in this field since its early days, defining the characteristics, compatibility and interchangeability of electronic components and assemblies which in turn become parts of still larger systems. While technology has in recent years advanced from single to multifunction components, with dimensions going from macro to micro, signals from analogue to digital, and speeds from seconds to less than nanoseconds, the philosophy and principles underlying the IEC's work, however, remain the same: defining the characteristics, and ensuring compatibility and interchangeability of 170
components and assemblies at all stages so that they can be built into complete systems. To meet the needs of users of this continually evolving technology, the IEC has expanded the number of its Technical Committees working in the electronics and telecommunications field to cover a wide range of components, measurement and control devices, telecommunications and electronic equipment. As early as 1955 the IEC's work in the electronics and telecommunications field had expanded to such an extent that a special management body, the Advisory Committee on Electronics and Telecommunications (ACET), was set up to 10ok after the interests of this dynamic sector. During a meeting held in Montreux in June 1981, the Committee of Action of the IEC created a group whose brief is to co-ordinate IEC work in information technology with that of other international bodies, primarily CCIR (International Radio Consultative Committee), CCITT (International Telephone and Telegraph Consultative Committee) and ISO (International Organization for Standardization), and to co-ordinate work in this field within the IEC to ensure that there are neither overlaps nor gaps. To date, this group has achieved a great deal. One of its first actions was to recommend the creation of a new Technical Committee to be responsible for information technology equipment. This recommendation was endorsed by the IEC Council at its meeting in Rio de Janeiro in June 1982, and subsequently, TC 83: Information Technology Equipment, held its first meeting in Wiesbaden in April 1983. ISO/TC 97 and IEC/TC 83 have made special arrangements for collaboration to ensure efficient co-ordination. This means, for example, that these Technical Committees are now mutually represented at each other's meetings. The IEC actively co-operates with organizations such as CCITT and CCIR,
where co-operation dates back to 1927 and 1933 respectively, and with the ISO, in identifying areas where co-ordination is needed and making sure that agreed-upon international standards remain aligned. To speed up the availability of IT standards, the IEC may now issue as IEC standards those of recognized organizations whose texts are in conformity with IEC requirements. The IEC's long experience in component and systems technology, together with the co-ordination the Advisory Committee on Electronics and Telecommunications (ACET) and the Information Technology Co-ordinating Group (ITCG) bring to a complex area, leave it well placed to serve its users in this expanding field.
IEC's History The IEC's work in electronics and telecommunications started in the 1930's in the field of radiocommunications with single-function components for radios-resistors, capacitors, electronic tubes, cables and connectors--the technology that brought radio and television to millions of homes. Like systems in other areas of the IEC's work, these systems required compatibility at all stages. The transfer of the radio signal or television image from the studio through the earth transmitting station or communications satellite to the listener or viewer, demands the proper co-ordinated functioning of tens of thousands of components and assemblies all requiring international standards to work together. The invention of the transistor followed by the growth of microelectronics, and then digital microelectronics, called for IEC standards for a new wave of multifunction components--the semiconductor devices and integrated circuits, the building blocks of the Information Technology society. These miniaturized components made it possible to adopt digital technology as the quickest, most reliable and cost-efficient means of transmitting information. They also made it possible to put increasing amounts of intelligence into many kinds of equipment. These capabilities demanded new requirements from the IEC to ensure that the interface condi-tions of these components within the various systems were met.
At the same time rapid expansion of the home entertainment industry saw the IEC move into sound recording and reproduction and video systems, producing standards for records, digital optical recording disks, audio and video cassettes, microphones and loudspeakers. In industry, the move to automation produced demands for IEC standards for electrical and electronic equipment for industrial machines. The introduction of control systems into industrial processes saw IEC standards developed for analogue systems, and with the introduction of digital techniques, for digital data communications systems as well. The development of new techniques in the power electronics industry, brought about by powerful new semiconductor value devices, and the introduction of large numbers of integrated circuits, has seen the IEC continually updating standards in the power electronics field to provide standards when needed. The increasing use of nuclear power, together with stringent safety requirements, has resulted in more than 100 IEC standards in the fields of nuclear and reactor instrumentation and radiation protection instrumentation. To keep pace with the rapid developments in the data processing field, IEC produced standards covering the safety of this equipment. Because of the introduction of laser techniques in a variety of equipment, the IEC has produced the first world-wide safety standards for the radiation safety of laser products and a standard covering the electrical safety of laser equipment and installations. In the field of fibre optics, which has opened up new dimensions in information transmission, the IEC has produced the first world standards for optical fibres and optical fibre cables. Work is underway within the IEC on rapidly developing more standards for this field. The IEC is also co-operating with the CCITT in this area. To promote common understanding among engineers and scientists in the electronics and telecommunications field, the IEC has published a vocabulary in nine languages, the International Electrotechnical Vocabulary (IEV) which includes terms and definitions for electronics, radiocommunications, space radiocommunications, telegraphy and telephony, electroacoustics, nuclear in-
strumentation, power electronics, automatic control and the recording and reproduction of sound and video. A wide range of graphical symbols suitable for computer-aided design have also been produced for discrete and integrated, analogue and digital components. Work on reliability of electronic components and equipment, closely linked with the complex electronic systems found in IT equipment, has resulted in a number of standards for reliability and maintainability. The IEC has also developed standard methods of test and measurement and set down requirements for measuring instruments, allowing the characteristics of components and equipment offered for sale internationally to be measured by the same tests.
gather, process, transfer and exchange it means that this equipment must be able to interconnect as part of a system, and communicate using the same protocols or rules. IEC work here ranges from buses to link microprocessors, buses to interconnect instruments, and buses for complete industrial process control systems. Here work is nearing completion on two microprocessor systems buses which will allow data transfer between a variety of microprocessors. At the instrument level a standard for an interface system for programmable measuring instruments has been issued.
System Applications
The IEC is producing standards for semiconductor devices, integrated circuits and microprocessor systems, the basic elements of Information Technology systems. Because developments in this field are so rapid, standardization covers the minimum number of characteristics to be specified for interface conditions, including the exchange of data between these components and the systems in which they are used. IEC standards exist for analogue and digital integrated circuits, microprocessors and discrete devices, r IEC standards have also been developed for electroni~ tubes, such as cathode ray tubes; capacitors and resistors, including miniaturized types which allow a very high component density; all types of low frequency cables, coaxial cables and radio frequency connectors; electromechanical components including low frequency connectors, switches, racks and panels; piezoelectric devices for frequency control and selection; magentlc components and ferrite materials used in telecommunications; printed boards and flexible printed circuits; and lithium cells used for back-up power supplies for memory retention.
To accelerate the work, and to serve the growing and changing needs of industries and users which have been created by Information Technology, the IEC has adopted a systems approach to IT standards and is co-operating closely with the CCITT and the CCIR. The approach enables development of standards for entire systems as well as for specific components or pieces of equipment. It also allows manufacturers to design systems and then the equipment to fit into them, rather than designing ways for existing products to fit together, although the latter case still happens. The IEC is now working on standards for one home electronics bus, or channel for transmission signals, to interconnect all electronic equipment in the home. Methods by which this bus will fit into the CCITT's Integrated Services Digital Network (ISDN) are being followed closely by the IEC.
Transmission, Installation and Distribution The trend towards incorporation of the computing function into a wide variety of equipment, not only decentralized data processing, personal computers and word processors, but also a host of other appliances, has magnified the need for interconnection and communication between equipment. To have access to information, to
Components
Safety Safety of equipment and total systems for Information Technology users is a major priority in the creation of IEC international standards. A basic safety standard exists for mains-operated electronic equipment, 171
such as radios and television receivers, amplifiers, record players and recorders, used in the home and similar locations. Sophisticated electromedical equipment, already covered by IEC standards, is now increasingly combined with computers and electronic measuring devices. The IEC will study requirements for the safety of this combined equipment. The IEC is cooperating with the CCITT in producing guidelines covering the safety aspects of equipment connected to telecommunications networks.
Software The IEC has prepared software standards for certain electronic systems.
172
These are based on ISO standards which cover basic aspects of software, and there is continuing co-operation between the ISO and the IEC.
Electromagnetic Compatibility The problem of interference in equipment caused by electromagnetic signals or disturbances has resulted in a number of IEC standards. Under the auspices of the IEC, the International Special Committee on Radio Interference (CISPR) has produced standards dealing with interference caused by industrial, scientific and medical radiofrequency equipment, sound and televi-
sion receivers and household electrical appliances. Without the work of the CISPR, sound broadcasting would not have developed as it did in the 1930's, paving the way for the modern electronic age. Work is now underway within CISPR on a standard which describes the limits of interference and measuring methods for IT equipment.