US5583757A — Method of input signal resolution for actively re…

Claim 1

Independent Claim 222 words

A method of input signal resolution in a process control system having a plurality of actively redundant process control computers, where each of said actively redundant process control computers receives corresponding input signals from the physical process being controlled, comprising the steps of: mutually exchanging at least one block of said corresponding input signals between each of said actively redundant process control computers, each of said blocks of corresponding input signals including at least one input signal from the physical process being controlled, a first indicator which represents the validity of the at least one input signal contained in said block and a second indicator which characterizes the block of input signals to be exchanged; performing at least one comparison to each of said actively redundant process control computers using said second indicator to determine the success of said mutual exchange of said block of corresponding input signals; individually selecting an input valve at each of said actively redundant process control computers for each of said input signs exchanged, said selecting step being responsive at least in part to said first indicator to determine which of said corresponding input values to select; and recording an indication at each of said actively redundant process control computers to identify which of the corresponding input signals were selected by that actively redundant process control computer.

Claim 2

Independent Claim 222 words

A method of input signal resolution in a process control system having a plurality of actively redundant process control computers, where each of said actively redundant process control computers receives corresponding input signals from the physical process being controlled, comprising the steps of: mutually exchanging at least one block of said corresponding input signals between each of said actively redundant process control computers, each of said blocks of corresponding input signals including at least one input signal from the physical process being controlled, a first indicator which represents the validity of the at least one input signal contained in said block and a second indicator which characterizes the block of input signals to be exchanged; performing at least one comparison to each of said actively redundant process control computers using said second indicator to determine the success of said mutual exchange of said block of corresponding input signals; individually selecting an input valve at each of said actively redundant process control computers for each of said input signs exchanged, said selecting step being responsive at least in part to said first indicator to determine which of said corresponding input values to select; and recording an indication at each of said actively redundant process control computers to identify which of the corresponding input signals were selected by that actively redundant process control computer.

Claim 3

Dependent Claim 44 words

The method according to claim 1, wherein there are at least three corresponding input signals, and said step of recording an indication includes at least one indicator bit for each of said corresponding input signals whose value identifies which corresponding input signal was selected.

Claim 4

Dependent Claim 28 words

The method according to claim 1, wherein a plurality of blocks of said corresponding input signals are mutually exchanged between each of said actively redundant process control computers.

Claim 5

Dependent Claim 37 words

The method according to claim 3, wherein said step of individually selecting an input value is performed for each of said input signals in an exchanged block before another block of said corresponding input signals are exchanged.

Claim 6

Dependent Claim 71 words

The method according to claim 1, further including the step of periodically transmitting a clocking signal from one of said actively redundant process control computers to the other of said actively redundant process control computers to coordinate each of said actively redundant process control computers by making periodic phase corrections, such that said mutually exchanging step is performed without interrrupting the central processing units of said actively redundant process control computers.

Claim 7

Dependent Claim 31 words

The method according to claim 5, wherein said clocking signal is transmitted at a predetermined pseudo time domain rate during each process control cycle of said actively redundant process control computers.

Claim 8

Independent Claim 284 words

A method of input signal resolution in a process control system having a plurality of actively redundant process control computers, where each of said actively redundant process control computers receives corresponding input signals which represent analog values from a physical process being controlled with each process control cycle, comprising the steps of: mutually exchanging at least one block of said corresponding input signals between each of said actively redundant process control computers; determining if a predefined tolerance has been exceeded between the analog values of at least some of said corresponding input signals, and if said predefined tolerance was exceeded during the present process control cycle, then determining if said predefined tolerance was also exceeded in at least the last process control cycle; individually selecting an analog input value at each of said actively redundant process control computers for each of said input signals exchanged where said predefined tolerance was not exceeded in the present process control cycle; employing the analog input value selected in the last process control cycle to decide process control outputs in the present process control cycle where said predefined tolerance was exceeded during the present process control cycle, but not the immediately prior process control cycle; and using a predetermined magnitude criteria to individually select an analog input value at each of said actively redundant process control computers when it has been determined that said predefined tolerance was exceeded for the present process control cycle and at least the last process control cycle; wherein each of said corresponding input signals is provided with its own predetermined magnitude criteria which includes at least one bit to alternatively represent a select-high and a select-low basis for selecting the analog input value.

Claim 9

Independent Claim 284 words

A method of input signal resolution in a process control system having a plurality of actively redundant process control computers, where each of said actively redundant process control computers receives corresponding input signals which represent analog values from a physical process being controlled with each process control cycle, comprising the steps of: mutually exchanging at least one block of said corresponding input signals between each of said actively redundant process control computers; determining if a predefined tolerance has been exceeded between the analog values of at least some of said corresponding input signals, and if said predefined tolerance was exceeded during the present process control cycle, then determining if said predefined tolerance was also exceeded in at least the last process control cycle; individually selecting an analog input value at each of said actively redundant process control computers for each of said input signals exchanged where said predefined tolerance was not exceeded in the present process control cycle; employing the analog input value selected in the last process control cycle to decide process control outputs in the present process control cycle where said predefined tolerance was exceeded during the present process control cycle, but not the immediately prior process control cycle; and using a predetermined magnitude criteria to individually select an analog input value at each of said actively redundant process control computers when it has been determined that said predefined tolerance was exceeded for the present process control cycle and at least the last process control cycle; wherein each of said corresponding input signals is provided with its own predetermined magnitude criteria which includes at least one bit to alternatively represent a select-high and a select-low basis for selecting the analog input value.

Claim 10

Dependent Claim 34 words

The method according to claim 7, including the step of setting an individual compare bit when said corresponding input signals have been determined to exceed said predefined tolerance in the present process control cycle.

Claim 11

Dependent Claim 40 words

The method according to claim 7, including the step of setting a general problem bit when any of said corresponding input signals in said block of corresponding input signals have exceeded said predefined tolerance in the present process control cycle.

Claim 12

Dependent Claim 45 words

The method according to claim 9, wherein the analog input value selected in the last process control cycle is employed where said predefined tolerance was exceeded during the present process control cycle and said general problem bit was set in the last process control cycle.

Claim 13

Dependent Claim 20 words

The method according to claim 7, wherein the same predefined tolerance is provided for each of said corresponding input signals.

Claim 14

Dependent Claim 16 words

The method according to claim 11, wherein said predefined tolerance is a percentage of full scale.

Claim 15

Dependent Claim 31 words

The method according to claim 12, wherein said percentage of full scale includes both a positive and negative percentage of full scale for at least one of said corresponding input values.

Claim 16

Dependent Claim 40 words

The method according to claim 7, further including the step of recording an indication at each of said actively redundant process control computers to identify which of the corresponding input signals were selected by that actively redundant process control computer.

Claim 17

Independent Claim 301 words

A method of input signal resolution in a process control system having a plurality of actively redundant process control computers, where each of said actively redundant process control computers receives corresponding input signals which represent analog values from a physical process being controlled with each process control cycle, comprising the steps of: mutually exchanging at least one block of said corresponding input signals between each of said actively redundant process control computers; determining if a predefined tolerance has been exceeded between the analog values of at least some of said corresponding input signals, and if said predefined tolerance was exceeded during the present process control cycle, then determining if said predefined tolerance was also exceeded in at least the last process control cycle; individually selecting an analog input value at each of said actively redundant process control computers for each of said input signals exchanged where said predefined tolerance was not exceeded in the present process control cycle; and employing the analog input value selected in the last process control cycle to decide process control outputs in the present process control cycle where said predefined tolerance was exceeded during the process control cycle, but not the immediately prior process control cycle; wherein a plurality of blocks of said corresponding input signals are mutually exchanged between each of said actively redundant process control computers, and each of said blocks of corresponding input signals includes at least one word which represents the validity of the input signals contained in said block and wherein said mutual exchange step includes the steps of determining a validity indicator from said block of corresponding input signals as received, and comparing said determined validity indicator with the validity indicator that was received with a block of corresponding input signals to determine the validity of said mutual exchange step.

Claim 18

Independent Claim 301 words

A method of input signal resolution in a process control system having a plurality of actively redundant process control computers, where each of said actively redundant process control computers receives corresponding input signals which represent analog values from a physical process being controlled with each process control cycle, comprising the steps of: mutually exchanging at least one block of said corresponding input signals between each of said actively redundant process control computers; determining if a predefined tolerance has been exceeded between the analog values of at least some of said corresponding input signals, and if said predefined tolerance was exceeded during the present process control cycle, then determining if said predefined tolerance was also exceeded in at least the last process control cycle; individually selecting an analog input value at each of said actively redundant process control computers for each of said input signals exchanged where said predefined tolerance was not exceeded in the present process control cycle; and employing the analog input value selected in the last process control cycle to decide process control outputs in the present process control cycle where said predefined tolerance was exceeded during the process control cycle, but not the immediately prior process control cycle; wherein a plurality of blocks of said corresponding input signals are mutually exchanged between each of said actively redundant process control computers, and each of said blocks of corresponding input signals includes at least one word which represents the validity of the input signals contained in said block and wherein said mutual exchange step includes the steps of determining a validity indicator from said block of corresponding input signals as received, and comparing said determined validity indicator with the validity indicator that was received with a block of corresponding input signals to determine the validity of said mutual exchange step.

Claim 19

Independent Claim 197 words

A method of input signal resolution in a process control system having a plurality of actively redundant process control computers, and at least one triply redundant computer unit which selects an analog input value from at least one set of corresponding analog input signals by at least two of three computers contained in said triply redundant computer unit; comprising the steps of: transmitting said input value selected from each of said two computers contained in said triply redundant computer unit to at least one of said actively redundant process control computers; determining if a predefined tolerance has been exceeded between the analog values of said transmitted signals at each of said actively redundant process control computers; using a predetermined magnitude criteria to individually select the analog input value to be employed in process control decisions at each of said actively redundant process control computers when it has been determined that said predefined tolerance was exceeded; wherein each of said corresponding analog input signals is provided with its own predetermined magnitude criteria; and wherein said predetermined magnitude criteria includes at least one bit to alternatively represent a select-high and a select-low basis for selecting the analog input value.

Claim 20

Independent Claim 197 words

A method of input signal resolution in a process control system having a plurality of actively redundant process control computers, and at least one triply redundant computer unit which selects an analog input value from at least one set of corresponding analog input signals by at least two of three computers contained in said triply redundant computer unit; comprising the steps of: transmitting said input value selected from each of said two computers contained in said triply redundant computer unit to at least one of said actively redundant process control computers; determining if a predefined tolerance has been exceeded between the analog values of said transmitted signals at each of said actively redundant process control computers; using a predetermined magnitude criteria to individually select the analog input value to be employed in process control decisions at each of said actively redundant process control computers when it has been determined that said predefined tolerance was exceeded; wherein each of said corresponding analog input signals is provided with its own predetermined magnitude criteria; and wherein said predetermined magnitude criteria includes at least one bit to alternatively represent a select-high and a select-low basis for selecting the analog input value.

Claim 21

Dependent Claim 29 words

The method according to claim 16, including the step of setting an individual compare bit when the analog values of said transmitted input signals have exceeded said predefined tolerance.

Claim 22

Dependent Claim 31 words

The method according to claim 16, including the step of setting a general problem bit when any of the analog values of said transmitted input signals have exceeded said predefined tolerance.

Claim 23

Dependent Claim 30 words

The method according to claim 16, including the step of mutually exchanging a least one set of said transmitted input signals between each of said actively redundant process control computers.

Claim 24

Dependent Claim 39 words

The method according to claim 16, including the step of recording an indication at each of said actively redundant process control computers to identify which of the transmitted input signals were selected by that actively redundant process control computer.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1999-12-10	2000-06-10	2000-12-10	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2003-12-10	2004-06-10	2004-12-10	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2007-12-10	2008-06-10	2008-12-10	$7700.00	Window Closed / Lapsed

Method of input signal resolution for actively redundant process control computers

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag