The Multi-Point Interface – Siemens (MPI) is a proprietary

Proprietary hardware

Proprietary hardware is computer hardware which is owned by the proprietor.Historically, most early computer hardware was designed as proprietary until the 1980s, when IBM PC changed this paradigm...

 interface

Interface (computer science)

In the field of computer science, an interface is a tool and concept that refers to a point of interaction between components, and is applicable at the level of both hardware and software...

 of the programmable logic controller

Programmable logic controller

A programmable logic controller or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines...

 SIMATIC S7 of the company Siemens

Siemens AG

Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....

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It is used for connecting the stations programming (PG or personal computer), operator consoles, and other devices in the SIMATIC family. This technology has inspired the development of protocol Profibus

Profibus

PROFIBUS is a standard for field bus communication in automation technology and was first promoted in 1989 by BMBF...

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The MPI is based on the standard EIA-485 (formerly RS-485) and works with a speed of 187.5 kBd

Baud

In telecommunications and electronics, baud is synonymous to symbols per second or pulses per second. It is the unit of symbol rate, also known as baud rate or modulation rate; the number of distinct symbol changes made to the transmission medium per second in a digitally modulated signal or a...

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The network

Computer network

A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....

 MPI must have resistance

Resistor

A linear resistor is a linear, passive two-terminal electrical component that implements electrical resistance as a circuit element.The current through a resistor is in direct proportion to the voltage across the resistor's terminals. Thus, the ratio of the voltage applied across a resistor's...

 at the end of the line generally included in the connector

Electrical connector

An electrical connector is an electro-mechanical device for joining electrical circuits as an interface using a mechanical assembly. The connection may be temporary, as for portable equipment, require a tool for assembly and removal, or serve as a permanent electrical joint between two wires or...

 and activated by a simple switch.

Manufacturers using MPI technology offer a range of connections to a PC: MPI cards, PCMCIA cards, USB

Universal Serial Bus

USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....

 adapters or Ethernet

Ethernet

Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....

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(1) Article in original language : http://fr.wikipedia.org/wiki/Multi_Point_Interface_-_Siemens