Automatic/remote RF instrument reading method and apparatus
US4614945A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1985 |
| Grant date | Sep 30, 1986 |
| Priority date | — |
| Expiry date | Feb 20, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY04S20/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An automatic/remote instrument monitoring system and method are disclosed. RF transponder units are operatively connected to and monitor one or more parameters of a remotely located instrument. The transponders include RF receivers that sample received RF signals at a low duty cycle and look for a common wake-up signal transmitted from a mobile data collection unit. All transponders receiving the common wake-up signal simultaneously energize their respective transmitters and transmit their respective messages over a predetermined RF transmission bandwidth to receivers in the mobile unit. The time and frequency parameters of the transponder transmissions are varied in a manner such that the transmission signals of simultaneously transmitting transponders differ. A plurality of RF receivers in the mobile unit are respectively tuned to collectively receive the transponder transmissions, across the entire transmission bandwidth. Decoding and signal processing circuits in the mobile receiver unit identify transmitting transponders and process their respective messages.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.