Data communications systems employing redundant series transmission loops
US4159470A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1977 |
| Grant date | Jun 26, 1979 |
| Priority date | — |
| Expiry date | May 16, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/745
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A loop communication system includes a loop controller originating and terminating parallel output multiple bit message frames over a pair of trunks to remote stations, each of which includes a multiplexing connection means to the incoming trunk segments, with means to selectively and operably connect one of the incoming trunk segments to a frame processor. A pair of transmitters are also provided at the interface means and actuated to synchronously and correspondingly retransmit the process signal over the two outgoing trunk lines or segments. A logic circuit directly transmits the signal from one receiver and blocks the other until the first fails. The message is processed and retransmitted by a pair of transmitters over the two outgoing trunk segments. Suitable indicators coupled into the logic circuit signal the failure. A contact status circuit initiates transmission of the failure location via message frames to the controller. A control switch by-passes the station and is operable manually or in response to a power failure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.