Telemetry access arrangement
CA 2193077 C · Owner: At&T Corp. · Inventors: Schull, Jerome W.; Garland, Stuart Mandel
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to a method and apparatus for accessing customer meters and for controlling customer devices over a telephone line. A connection using only a single distinctive brief burst of power ringing or tone is established over a customer line between a central office and customer station equipment to alert both the customer and the customer premises equipment (CPE) or a short burst of tone to alert the CPE. The connection is between a data accessing device such as a meter reading controller and a customer premises device such as a meter interface unit. Signals are exchanged over the connection between these two units without alerting the customer via a ringing signal …
Read the whole patent
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 January 26, 1995 and granted August 31, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 26, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 26, 2017.
- 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.