US4785285A
Expired / Lapsed
US
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Parallel bus alarm system
Assignee: Tracer Electronics Inc
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Filing: 1987-03-18
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Granted: 1988-11-15
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Expires: 2007-03-18
Abstract
Abstract A parallel bus alarm system in which address signals are represented by successive voltage steps, and responses are represented by current increments. Each alarm element, in response to its addressing, controls a variable current increment to flow in the bus, the magnitude of the current increment being a function of an associated analog measurement to be reported. Each alarm element also causes a predetermined current increment to flow in the bus in response to a condition arising which requires reporting, the total current change thus being directly proportional to the number of alarm indications.
Inventors
- 👤 Rudor M. Teich
- 👤 Keith Guillaume
- 👤 Ram Shalvi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:45
CPC Classifications
G; G08; G08B; G08B26/00; G08B26/001; G08B26/002
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
162 words
A parallel bus alarm system comprising a bus; a plurality of alarm means connected in parallel across said bus; and control means for causing a DC quiescent current to flow in said bus and for pulsing the potential across said bus to extend addressing signals to said alarm means; each of said alarm means including means for changing said DC quiescent current upon the occurrence of an alarm condition, and means responsive to addressing of the alarm means for controlling the current flowing in said bus to change by a variable increment whose magnitude is a function of an associated analog measurement to be reported; said control means including means for detecting a change in said DC quiescent current to determine the occurrence of at least one alarm condition, and means responsive to subsequent addressing of said alarm means for measuring the current in said bus so as to ascertain the magnitude of the current change controlled by an addressed alarm means.
Claim 2
Dependent Claim
162 words
A parallel bus alarm system comprising a bus; a plurality of alarm means connected in parallel across said bus; and control means for causing a DC quiescent current to flow in said bus and for pulsing the potential across said bus to extend addressing signals to said alarm means; each of said alarm means including means for changing said DC quiescent current upon the occurrence of an alarm condition, and means responsive to addressing of the alarm means for controlling the current flowing in said bus to change by a variable increment whose magnitude is a function of an associated analog measurement to be reported; said control means including means for detecting a change in said DC quiescent current to determine the occurrence of at least one alarm condition, and means responsive to subsequent addressing of said alarm means for measuring the current in said bus so as to ascertain the magnitude of the current change controlled by an addressed alarm means.
Claim 3
Dependent Claim
24 words
A parallel bus alarm system in accordance with claim 1 wherein said control means has a source impedance in the order of several ohms.
Claim 4
Dependent Claim
37 words
A parallel bus alarm system in accordance with claim 1 wherein each of said alarm means includes means for controlling a predetermined current change in said DC quiescent current responsive to the occurrence of an alarm condition.
Claim 5
Dependent Claim
43 words
A parallel bus alarm system in accordance with claim 1 wherein said control means includes a microprocessor, and means whose operation is independent of said addressing for generating an alarm signal responsive to a sufficient change taking place in said DC quiescent current.
Claim 6
Dependent Claim
65 words
A parallel bus alarm system in accordance with claim 1 further including additional means connected across said bus responsive to a predetermined addressing signal for controlling a fixed current to flow in said bus, said fixed current being at a level outside the normal response range of said plurality of alarm means, said additional means serving to verify that addressing signals have been received correctly.
Claim 7
Dependent Claim
37 words
A parallel bus alarm system in accordance with claim 1 wherein the controlling means in each of said alarm means controls said current change in said bus while said control means applies a potential across said bus.
Claim 8
Dependent Claim
138 words
A parallel bus alarm system comprising a bus; a plurality of alarm means connected in parallel across said bus; and control means for causing a DC quiescent current to flow in said bus and for pulsing the potential across said bus to extend addressing signals to said alarm means; each of said alarm means including means responsive to addressing of the alarm means for controlling the current flowing in said bus to change by a variable increment whose magnitude is a function of an associated analog measurement to be reported; said control means including means for forming an analog representation of a change in the current flowing in said bus responsive to addressing of an alarm means, and means for measuring said analog representation to ascertain the magnitude of the current change controlled by the addressed alarm means.
Claim 9
Dependent Claim
138 words
A parallel bus alarm system comprising a bus; a plurality of alarm means connected in parallel across said bus; and control means for causing a DC quiescent current to flow in said bus and for pulsing the potential across said bus to extend addressing signals to said alarm means; each of said alarm means including means responsive to addressing of the alarm means for controlling the current flowing in said bus to change by a variable increment whose magnitude is a function of an associated analog measurement to be reported; said control means including means for forming an analog representation of a change in the current flowing in said bus responsive to addressing of an alarm means, and means for measuring said analog representation to ascertain the magnitude of the current change controlled by the addressed alarm means.
Claim 10
Dependent Claim
65 words
A parallel bus alarm system in accordance with claim 7 further including additional means connected across said bus responsive to a predetermined addressing signal for controlling a fixed current to flow in said bus, said fixed current being at a level outside the normal response range of said plurality of alarm means, said additional means serving to verify that addressing signals have been received correctly.
Claim 11
Dependent Claim
172 words
A parallel bus alarm system comprising a bus; a plurality of alarm means connected in parallel across said bus; control means for causing a DC quiescent current to flow in said bus and for pulsing the potential across said bus to extend addressing signals to said alarm means; each of said alarm means including means responsive to addressing of the alarm means for controlling the current flowing in said bus to change by a variable increment whose magnitude is a function of an associated analog measurement to be reported; said control means including means for measuring a current change in said bus so as to ascertain the magnitude of the current change controlled by an addressed alarm means; and additional means connected across said bus responsive to a predetermined addressing signal for controlling a fixed current to flow in said bus, said fixed current being at a level outside the normal response range of said plurality of alarm means, said additional means serving to verify that addressing signals have been received correctly.
Claim 12
Dependent Claim
172 words
A parallel bus alarm system comprising a bus; a plurality of alarm means connected in parallel across said bus; control means for causing a DC quiescent current to flow in said bus and for pulsing the potential across said bus to extend addressing signals to said alarm means; each of said alarm means including means responsive to addressing of the alarm means for controlling the current flowing in said bus to change by a variable increment whose magnitude is a function of an associated analog measurement to be reported; said control means including means for measuring a current change in said bus so as to ascertain the magnitude of the current change controlled by an addressed alarm means; and additional means connected across said bus responsive to a predetermined addressing signal for controlling a fixed current to flow in said bus, said fixed current being at a level outside the normal response range of said plurality of alarm means, said additional means serving to verify that addressing signals have been received correctly.
References Cited (Backward Citations)
US4555695A
Cited
US4613848A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |