Wire data transmission system
US4423506A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1981 |
| Grant date | Dec 27, 1983 |
| Priority date | — |
| Expiry date | Apr 29, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2203/5495
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a wire data transmission system which transmits data from a master station to a number of slave stations or vice versa through a pair of signal wires connected in parallel with each other, only the master station need be provided with a data transmission power source. Signal lines receiving DC voltage from the power source through a resistor are periodically short-circuited within the master station, thereby to transmit "1" or "0" encoded data according to the duration of the short-circuiting time of the signal lines, along with an identification code which designates a slave station. In the slave station, a variation of a voltage between the signal lines is detected, so that the slave station receives the identification code and encoded data from the master station, and a state of short circuit between lines corresponding to encoded data or a clock pulse from the master station is changed by short-circuiting the signal lines, so that the slave station transmits the encoded data to the master station. The master station detects the change of the code transmitted therefrom to receive the encoded data from the slave station. When a short circuit fault occurs between the lines in t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.