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US4151590A Expired / Lapsed US ⏱️ 0.0 years remaining

Process control system

Assignee: Yokogawa Electric Corp
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Filing: 1977-11-15
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Granted: 1979-04-24
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Expires: 1997-11-15
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Abstract

Abstract A process control system for multiplex operation of several process control loops. The system includes process input and process output units, analog and computer operation units and operator's interface stations, the exchange of process information between these units and stations being carried out by a time-sharing technique. The system is provided with a first data trunk through which process information through the data trunk is carried out in synchronism with address signals supplied to the address trunk in accordance with a cyclic control routine. Also included is a second data trunk which makes it possible at one's option to modify the cyclic control routine to select a desired mode of operation, the analog and computer operation units and the interface stations signalling whether operation in the manual control, analog control, or control mode is possible. State signals are generated at the operator's interface stations to the respective units to control their signal transmitting or receiving state.

Inventors

  • 👤 Tadashi Azegami

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 19:41
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/04; G05B19/042; G05B19/0421

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 176 words
A process control system for multiplex operation of several process control loops, the system being provided with process input and process output units, analog controller and computer operation units, and operator's interface stations, the exchange of information between the units and stations being carried out on a time-sharing basis, the system comprising: (A) a first data trunk coupled to said units and stations to convey process information; (B) an address trunk coupled to said units and stations to which address signals are supplied in accordance with a cyclic control routine to synchronize the exchange of information through the first data trunk; and (C) means including a second data trunk having a group of lines making it possible, at one's option, to modify the cyclic control routine to select a desired mode of operation, said analog controller and computer operation units and said interface stations signalling whether operation in the manual, analog or computer state is possible, state signals being generated at the operator's interface stations to the respective units to control their transmitting or receiving state.
Claim 2
Dependent Claim 176 words
A process control system for multiplex operation of several process control loops, the system being provided with process input and process output units, analog controller and computer operation units, and operator's interface stations, the exchange of information between the units and stations being carried out on a time-sharing basis, the system comprising: (A) a first data trunk coupled to said units and stations to convey process information; (B) an address trunk coupled to said units and stations to which address signals are supplied in accordance with a cyclic control routine to synchronize the exchange of information through the first data trunk; and (C) means including a second data trunk having a group of lines making it possible, at one's option, to modify the cyclic control routine to select a desired mode of operation, said analog controller and computer operation units and said interface stations signalling whether operation in the manual, analog or computer state is possible, state signals being generated at the operator's interface stations to the respective units to control their transmitting or receiving state.
Claim 3
Dependent Claim 23 words
A system as set forth in claim 1, wherein said address signals are supplied to said address trunk by an address signal generator.
Claim 4
Dependent Claim 57 words
A system as set forth in claim 1, wherein said means includes a register operatively coupled to said second data trunk to select said state signals and to produce coding signals corresponding to the selection, the coding signals being applied to said units and stations and being decoded therein to control the transmitting and receiving states thereof.

References Cited (Backward Citations)

US3479493A Cited
US3526757A Cited
US3566355A Cited
US3694633A Cited
US3987351A Cited
US3760374A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-04-23 1982-10-23 1983-04-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-04-23 1986-10-23 1987-04-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-04-23 1990-10-23 1991-04-24 $7700.00 Window Closed / Lapsed

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