Dynamic self-checking safety circuit means
US4422067A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1981 |
| Grant date | Dec 20, 1983 |
| Priority date | — |
| Expiry date | Oct 5, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/16
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A safety circuit which connects a condition responsive circuit to a cyclic signal detecting circuit. In order to provide the cyclic signal detecting circuit with a continuous cyclic input, the condition responsive circuit and a cyclic redundancy checker is provided. The cyclic redundancy checker identifies a specific series of logic bits from the condition responsive circuit and responds favorably only to that series of logic bits. If any other series of logic bits occurs, the cyclic redundancy checker of the system ceases to function, thereby causing the cyclic signal detecting circuit to cease to function and it in turn opens a series contact to deenergize a critical load in a control system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.