Automatic resetting of control system for loss of time reference
US4403302A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1980 |
| Grant date | Sep 6, 1983 |
| Priority date | — |
| Expiry date | Oct 30, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B9/02
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In an electronic control system, as for instance, one employing a microcomputer, a timing reference signal supplied to the microcomputer, typically from the AC supply line, is monitored for continuity and integrity by determining whether that signal occurs or recurs some predetermined number of times relative to a measuring interval. The measuring interval is established by an event provided by the microcomputer and which recurs with a generally known time relationship to the timing reference signal. Failure of the timing reference signal to occur or recur within the measuring interval is interpreted as a failure of the timing reference, and a reset command is automatically executed to automatically reset or initialize the control system. A display, for instance associated with an appliance such as a microwave oven, may be repetitively scanned at some normal interval in response to the programmed control of a microcomputer. The measuring interval for monitoring the timing reference may be established from the display scan signal and the monitoring operation may be performed with a program stored in the microcomputer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.