VIPA CP 1413plus, Руководство пользователя, Страница: 37 / 328

CP1413plus manual Network planning
Rev. 00/07 2-19
2.7 Standards and specifications
Standards and specificationsThe main characteristic of a LAN is that it provides a single physical
communication path. The physical communication medium may consist of:
- one or more electrical connections (twisted cables)
- coaxial cable (triaxial cable)
- fiber-optic cable
The communications between individual stations is subject to certain standards and rules that must
be met by every station on the network. These determine the form of the communication protocol,
the access method to the LAN and other basic principles that are important for communicating on
the network.
The VIPA H1-network was developed to satisfy the ISO standards and specifications.
The standards and specifications for networking systems were determined by international and
national committees.
ANSI American National Standards Institute
This body is currently busy formulating agreements for high-speed LAN’s (100 MB/s) based on fiber-
optic technology in ANSI X3T9.5. (FDDI) Fiber Distributed Data Interface.
CCITT Committee Consultative Internationale de Telephone et Telegraph.
Amongst others, this advisory committee produces the specifications governing the interfacing of
industrial communication networks (MAP) and of office networks (TOP) to Wide Area Networks
(WAN).
ECMA European Computer Manufacturers Association.
generates the different standards for MAP and TOP.
EIA Electrical Industries Association (USA)
this committee determines standards like RS-232 (V.24) and RS-511.
IEC International Electrotechnical Commission.
This committee sets specific standards, e.g. those for the Field Bus.
ISO International Organisation for Standardization.
This association of national standards offices has determined the OSI-model
(ISO/TC97/SC16)
. It
outlines the framework for the standards that are applicable to data communications. The ISO
standards are converted to the different national standards like UL and DIN.
IEEE Institute of Electrical and Electronic Engineers (USA).
The project group 802 determines LAN-standards for communication speeds from 1 to 20 MB/s. IEEE
standards are often the basis ISO-standards, e.g. IEEE 02.3 = ISO 8802.3.
The serial Industrial Ethernet LAN is an open communication system that can be used for the
exchange of data between all devices that comply with a set of common rules. These devices may
also include units manufactured by other companies.
Data is communicated on the basis on the basis of the OSI ISO-reference model. This model
provides the specifications for all the processes, rules and the strategy for common data
communications.