Industrial control system
US4352103A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 24, 1980 |
| Grant date | Sep 28, 1982 |
| Priority date | — |
| Expiry date | Jan 24, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/2205
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A control system for controlling an industrial process includes a plurality of remotely located process control units (remotes) each coupled to an associated input/output device(s) and adapted to communicate with one another through a dual channel communications link. Each remote has a unique succession number within a predetermined succession order with supervisory communication-control of the communication link sequentially transferred to each remote according to its succession number to provide a revolving or master for the moment control of the system. Digital information in the form of data and control information blocks is transmitted between the remotes with the blocks transmitted twice on each channel of the communications link. The destination remote tests the block validity on one of the two dual channels and, if validated, responds with an acknowledgement signal (ACK) and, if invalid, tests the blocks on the other, alternate channel and then responds with an acknowledgement or non-acknowledgement signal (NAK) depending upon whether the data blocks tests on the alternate channel are found valid or invalid. A non-acknowledgement from the destination remote re-triggers the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.