Patent US4942572A successfully refreshed from Google Patents.
US4942572A
Expired / Lapsed
US
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Process and device for high speed polling
Assignee: International Business Machines Corp
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Filing: 1989-06-26
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Granted: 1990-07-17
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Expires: 2009-06-26
Abstract
Abstract A process is disclosed for efficiently polling low rate data terminals attached to communicate with a central station via a high speed channel. The process is based on the use of a dual rate polling mechanism involving first polling by using a high rate pseudo random sequence; monitoring the messages received back from the terminals; checking said messages for validity, and upon detecting an invalid message possibly indicating collision between terminal messages, then switching back into the first generated sequence at a lower conventional rate.
Inventors
- 👤 Jean-Louis Picard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:16
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/14; G06F13/20; G06F13/22; H; H04; H04L; H04L12/00; H04L12/28; H04L12/40; H04L12/403; H04L12/4013; H04L12/407; H04L12/413
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
202 words
A system for polling from a microprocessor controlled Communication Controller, N digital terminals made to communicate with said Controller via a high speed channel, said system including at the Controller site: means sensitive to an order from said microprocessor for generating and broadcasting a specific pattern announcing subsequent polling operations; a pseudo random generator sensitive to a subsequent order from said microprocessor for generating and broadcasting a first high rate equal to the bit rate, a random polling sequence of station addresses in which sequential station addresses are separated in time at the broadcasting rate by z bits of other station addresses where z is a whole number greater than or equal to 80. sensing means within said microprocessor controlled Communication Controller for monitoring the message received back from the terminals; inhibit means connected to said sensing means for subsequently broadcasting an inhibit message for inhibiting further message sending from the terminals upon a received message being detected by said sensing means; validity checking means sensitive to said sensing means for checking the validity of said received message; and means sensitive to an invalidity being reported by said validity checking means for switching said polling to a second low rate polling means.
Claim 2
Independent Claim
202 words
A system for polling from a microprocessor controlled Communication Controller, N digital terminals made to communicate with said Controller via a high speed channel, said system including at the Controller site: means sensitive to an order from said microprocessor for generating and broadcasting a specific pattern announcing subsequent polling operations; a pseudo random generator sensitive to a subsequent order from said microprocessor for generating and broadcasting a first high rate equal to the bit rate, a random polling sequence of station addresses in which sequential station addresses are separated in time at the broadcasting rate by z bits of other station addresses where z is a whole number greater than or equal to 80. sensing means within said microprocessor controlled Communication Controller for monitoring the message received back from the terminals; inhibit means connected to said sensing means for subsequently broadcasting an inhibit message for inhibiting further message sending from the terminals upon a received message being detected by said sensing means; validity checking means sensitive to said sensing means for checking the validity of said received message; and means sensitive to an invalidity being reported by said validity checking means for switching said polling to a second low rate polling means.
Claim 3
Dependent Claim
46 words
A polling system according to claim 1 wherein said second low rate polling means includes means for repeating at a lower rate the polling of a limited number of terminal addresses polled by the pseudo random generator just prior to the occurrence of an invalid check.
Claim 4
Dependent Claim
161 words
A polling process for polling from a central station N terminals made to communicate with said central station using digital frames including validity checking means, said process including steps of: generating and transmitting from said central station, a first polling sequence of station addresses at a first high rate equal to the bit rate and having sequential station addresses separated in transmitting time from one another by at least z bits of other station addresses, where z is a whole number greater than or equal to 80; monitoring at said central station the data received back from said terminals being polled; checking for validity the received data at said central station; and, upon detecting invalid data received, repeating at said central station and transmitting at a second lower rate a polling sequence addressing a limited number of the terminals just polled prior to the invalid check; and said method being characterized in that said first polling rate sequence is pseudo-randomly generated.
Claim 5
Dependent Claim
161 words
A polling process for polling from a central station N terminals made to communicate with said central station using digital frames including validity checking means, said process including steps of: generating and transmitting from said central station, a first polling sequence of station addresses at a first high rate equal to the bit rate and having sequential station addresses separated in transmitting time from one another by at least z bits of other station addresses, where z is a whole number greater than or equal to 80; monitoring at said central station the data received back from said terminals being polled; checking for validity the received data at said central station; and, upon detecting invalid data received, repeating at said central station and transmitting at a second lower rate a polling sequence addressing a limited number of the terminals just polled prior to the invalid check; and said method being characterized in that said first polling rate sequence is pseudo-randomly generated.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-16 | 1994-01-15 | 1994-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-16 | 1998-01-15 | 1998-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-16 | 2002-01-15 | 2002-07-17 | $7700.00 | Window Closed / Lapsed |