Terminal unit in information transmission system
US4910628A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1988 |
| Grant date | Mar 20, 1990 |
| Priority date | — |
| Expiry date | Sep 13, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2012/285
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A terminal unit for use in an information transmission system disposed between an information transmission line in the information transmission system constituted of signal lines for transmitting a signal by conduction therethrough of a direct current having positive polarity and negative polarity and controlled equipment as one terminal of the system, including at least a coupling circuit for transmitting and receiving a signal to and from the transmission line by converting the signal into a direct current as aforesaid and converting such a direct current into the signal, a transmission control device controlling transmission and reception of a signal according to a protocol for signal transmission, and a transmission circuit and a reception circuit disposed between the coupling circuit and transmission control device for making signal transmission and reception, respectively, and further, comprising a polarity detection circuit for detecting polarity of the direct current voltage supplied from the signal lines and a polarity switching circuit for switching polarities of a signal delivered to the transmission line depending upon the result of detection in the polarity detection c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.