Telephone dial-inbound data acquisition system with demand reading capability
CA 2071048 A1 · Owner: Schlumberger Resource Management Services, Inc. · Inventors: Ward, Steven M.; White, Darryl C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, A telephone dial-inbound data acquisition system with demand reading capability. The system has particular application for remotely reading utilitymeters. A remote data unit (RDU) dials up a host computer on a periodicbasis. The RDU is assigned a callback start time by the host computer. TheRDU calculates an actual callback time based on the callback start time and arandomly generated time delay. The RDU dials up the host computer via a modemwhen the local time as shown by an on-board real-time clock at the RDU equalsthe calculated actual callback time. Meter reading data is then transferred tothe host computer. The RDU also contains circuitry for detecting a pollingsignal …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed June 11, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 11, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 11, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.