FR2695525A1 - Operational equipment for local area computer network - uses carrier current signal on low voltage electricity supply network to link computers or data terminals - Google Patents

Abstract

The equipment consists of an electricity mains supply modem (B), a central unit (A) and an interface (C). The modem has an emitter (7-10), a receiver (11-16) and a mains interface (17-19). In a sending mode the carrier provided by an oscillator (7) is modulated by the incoming signal. In receiving mode, signals from the mains are treated by high pass and passband filters. The central unit (A) manages the communication of information and comprises program, configuration and transfer memories (1-3), a micro-controller (4) and a local interface (6). The interface module manages communication to computers or other peripherals by adapting and processing the signals. ADVANTAGE - Local data network may be operated using electricity supply mains e.g. 110, 220 or 380 V lines instead of dedicated cable system.

Description

The present invention relates to a device for producing a local computer network on carrier current using the mains lines.

Various techniques are already known for making local computer networks: thanks to metallic wires, coaxial cables, or optical fibers to which terminal data circuit equipment is connected at each end.

The present invention aims to eliminate the installation of a specific transmission medium, by using the wiring of power lines naturally present in all offices or all businesses, to eliminate any installation of additional specific wiring. Thus by connecting directly to the sector via a module each computer or each peripheral, it is possible to constitute a real computer network allowing to transmit data between computers, to share peripherals.

These aims are achieved by a device, in accordance with the invention which comprises the following elements: - A Sector Modem part - B - A Central Unit part - A - An Interface part - C
The modem part is designed for the transmission and reception of data and control signals on an electric current line, it works by the all-or-nothing modulation of a carrier (ASK: Amplitude Shift
Keying).

The Modem part is made up of three essential parts: - The Transmitter 7,8,9,10) - The Receiver (11,12,13,14,15,16) - The Sector interface (17,18,19)
The Issuer consists of the following elements:
The oscillator -7, The on / off switch of the carrier with positive logic- 8,
The output amplification stage - 9, The impedance adaptation stage - 10.

The Receiver consists of the following elements:
The Pre-filtering -11, The Limiter Amplifier -12, The Amplitude Filtering and Demodulation Stage -13, The Amplitude Modulation Cancellation Stage -14, Impulse Filtering -15, The RS Toggle -16.

The Sector Interface consists of the following elements:
The filtering system (band pass and high pass) -17, The limiter limiter -18, the coupling circuit and the link transformer -19.

In transmission mode the carrier provided by the oscillator is modulated in all or nothing by the input control signal.

The modulated signals are then amplified to the necessary HF level, and adapted to variations in the sector impedance.

In Reception mode, the signals received by the modem through the sector are processed by a system (High Pass, Band Pass, Active or Passive). This eliminates the harmful effects of variations in the line line charges, transient signals of large amplitudes, and different forms of noise such as impulse noise.

The Central Unit Part manages the communication of information and thus allows the analysis, processing and storage of data or orders.

It includes the following elements:
The EPROM containing the execution program -1, The EEPROM for saving the configuration of each module -2. it is possible to read or reprogram the configuration of each module through the use of specific utility software accessible at all times. This software thus makes it possible to introduce into each module the necessary information such as: the identity of each module (computer, peripheral, etc.), the destination of communications, the data encryption code.

 RAM - 3, which allow temporary storage of information during data transfer over the network between two modules.

The Micro Controller - 5, which by executing the program contained in the EPROM
controls the harmonious operation of all the modules by managing the
communication.

Interface - 6, which allows data exchange between the CPU part and the part
Modem modules.

The Interface Part manages the communication port of each module by adapting or processing the signals.

The assembly of the device according to the invention is particularly suitable for producing a local computer network operating by means of the carrier current, without the need for any additional specific wiring.

Claims (2)

1) Device allowing the creation of a local computer network on carrier current. Bidirectional modules modulating and demodulating all or nothing a carrier frequency, connect on one side directly on the line type 110,220 or 380 volts, on the other directly either on data terminals, or on computers, or on peripheral devices. characterized in that it comprises the following elements:  2) Device according to claim 1 characterized in that each bidirectional module and consisting of the following elements: Part B called Sector Modem which operates in Transmitter mode  Receiver on the power line, modulating and demodulating an ASK (Amplitude Shift Keying) type carrier. A party called Central Unit which, thanks to the instructions contained in its Eprom, stores, analyzes, and processes the data it receives or must transmit. A part C called Interface which works by converting the data from the U.C. part to the compatible format of the different equipment: Computers, terminals, printers, various peripherals, and conversely by converting the data for their processing by the U.C.