CA1185683A - Industrial process control system - Google Patents

Abstract

INDUSTRIAL PROCESS CONTROL SYSTEM

ABSTRACT OF THE DISCLOSURE

An industrial process control system in accordance with the present invention includes a plurality of device controllers connected together through a common buss with each device controller connected to an associated controlled device(s) that effect process control. A computer-aided system interface for controlling the overall system includes a visual display device in the form of a multi-color CRT and a graphic input device in the form of a transparent touch-responsive panel that overlies the CRT display screen.
Computer generated symbols representing the controlled devices are displayed on the CRT screen to define touch-responsive target areas. When an appropriate target area is touched by a human operator, a signal, such as a command signal, is generated to cause the controlled device whose symbol is displayed in the designated target area to respond, with this response being then indicated by a change in the device symbol being displayed on the screen. Other features include generation of a "hit" display to indicate the last coordinates on the display screen touched by the operator, a two-step execute command sequence for entering high priority commands into the system, and the changing of analog set point values as a function of the time that a selected target area is touched. The system advantageously eliminates some, if not all, input through a conventional keyboard so that the system operator interfaces with the system through easily comprehended and non-ambiguous visual symbols.

Description

~5~
INDUSTRIAL P~CESS C~NTROL ,SY~TE~

BACKGROUND OF THE INVENTION

~'ield of the Invention -The present inven-tion rela-tes to a computer controlled system for an industrial process and, more particularly, to a compu-ter controlled system for an industrial process in which interactive control by a human opera-~or is achieved -through a touch-responsive visuai display.
Many system--type indus-t.rial installat~ons, for example, those rela-ted to indus-trial process-type manufacturing and electrical power generation, employ a larger number oE
physically distributed controlled devices and associated sensors for effecting coordina-ted operation of the overall system. In the pas-t, coordinated control of various devices has been achieved by manual operation and various types of semi-automatic and fully au-tomatic control systems including electromagnetic re:Lay systems, hard-wired solid state logic sys-tems, and various -types of computer cont.rolled systems.
The computer systems have included central systems in which the various sensors and controlled devices are connected to a cen-tral computer, dis-tributed control systems in which a remotely located compu-ter is connec-t.ed to each of the control.led devices and to one another, and hybrid system combinations of the central and distributed systems.
In the computer-type control system, the man/machine interface has been typically accomplished with a cathode ray tube (CRT) visual display device in combination with a s-tandardized keyboard. To effec-t the entry o:E a command, the system operator usually must enter a code, such as an alpha-aumeric acronym or mnemonic, and then enter another code for the command to e~fect the requested information display, change in the operation of the controlled device, and/or change the set point of a sys-tem parame-ter. ~ecause , .~ -- 1 ~

-the en-try of this type of information requires correct depression of a se~uence of ~ey pads, keyboard entry of commands is dependent upon the skill of the system operator and is, of course, subject to error. The error rate inherent in this type of information and command entry has been recognized in the art and has given rise to often sophistica-ted entry verification programs by which an invalid entry will be recognized and an appropriate "invalid message" will be displayed to permit the operator to re-enter the message in correct form. While these types of validity checking programs are effective for the detection of mis-struck key pads in making alpha-numeric acronym or mnemonic entries, they are of no assistance when the sys-tem operator correctly enters an unintended mnemonic, e~g., when the operator intends to change the operationalstate of a pump but absen-tmindedly enters the correct mnemonic for a change in the operation o~ a compressor. The entry validity checking program will usually not detect this type of error.
SUMMA~Y OF THE ~VENTION
In view of the above, the present invention generally seeks to provide an industrial process control system in which system commands can be easily and reliably entered and further seeks to provide an industrial process control system in which commands and other information can be entered with a minimum error rate.
More particularly, the present invention seeks to provide an industrial process control system in which tha system operator can enter commands and other instructions to cause a change in the process in which a visual perception of the controlled device by the system operator and the command entry step are substantially related to one another to minimize errors.
Still further the present invention seeks to provide .~

an industrial process control system in which the system operato.r can enter commands and the like to cause a change in the operational state oE a con-trolled device in which a visually displayed symbol of the controlled device is spatially ~uxtaposed with a touch-responsive means so that touching of the vi.sually displayed symbol will also effect command entry into the system with the commanded response of the controlled d~vice then causing a change in the visually displayed symbol of the controlled device.
The invention in one broad aspect pertains to a system for controlling an industria:L process comprising a plurality of control means operable to effect changes in parameters of the process, the con-trol means each operable to effect changes in a different one of the parameters, a cathode ray tube and computer means. The computer means is capable of simultaneously defining a plurality of target areas at different locations on the face of the cathode ray tube each corresponding to a different one of the process parameters. ~he computer means is responsi.ve to the parameters in the process to control the cathode ray tube to display the status of the parameters at the corresponding target areas.
The computer means is responsive to a finger touching of a screen of the cathode ray tube to generate coordinate signals representing the position of the finger on the face of the cathode ray tube and is responsive to the coordlnate signals representing a position in one of the target areas to cause the corresponding control means to effect a change in a correspondin~ parameter of the process, the change being displayed by the cathode ray tube at the corresponding target area.
Anothcr aspec-t of the invention comprehends a con-trol system for controlling an indus-trial process including a plurality of controlled devices and assoclated device ~ 3 controllers Eor effecting control of process parameters, the controlled devices and associated device controllers in-terconnected through a communica-tlons link rneans to a control interface. The interface includes a visual display means having a vlsual display surface associated therewith and means for generatin~ symbols displayed simultaneously thereon representative of di~feren~ process parameters of the system, the symbols each having a displayed analog characteristic representin~ the value o~ an associated process parameter.
A touch-responsive means overlies the display surface and throu~h which the symbols are visible Means are provided for detecting the touchins of selected target areas on the touch-responsive means corresponding to the displayed sym~ols, the target areas including a first area loca-ted at each svmbol for incrementing the associated parameter and a second area loca-ted at each symhol separate from the first area for decrementing the associated parameter. ~eans are provided for generating a signal in response to the touchin~ of the first area and another signal in response to the touching of the second area, the first signal eEfective to incremen-t the associated process parameter and the second signal effective to decrement the associated process parameter.
The change in the process parameter causes a change in the analog characteristic of the corresponding displa~ved symbol on the visual display surface.
More particularly the industrial process system herein provides a plurality of process con-trol devices each connected for control thereof to an associated device controller. A common communications buss interconnects the device controllers with a command and :information interface means to permit communication there~etween. The command and information interface is provided ~or enterin~ commands, requests, information, and the like lnto -the s~stem and includes a visual display device such as a cathode ray tube (CRT) and a computer means for generating alpha-numeric characters ~or informa-tion display and pictorial symbols which graphically represent the controlled devices of the process.
The displayed symbols can include graphical representations of push buttons as well as more definite symbols such as a graphical representation of a pump or the like. A transparent or otherwise light -transmitting -touch-responsive panel overlies the CRT screen so that the CRT display surface will be in substantial registration with the touch--responsive panel.
System commands, including sequential-type commands as well as analog-type commands, are entered by manually touching an area of the touch-responsive screen in which a symbol appears. Upon entry of the command, the displayed symbol then changes in a selected manner, e.g., the color o~ the displayed symbol is changed, to indicate that the controlled device has responded in the input command. Other features of the invention include the display of a "hit" indicia to indicate the last position touched by the operator on the screen, a two-step entry procedure for inputting hlgh priority control signals to guard against error, and a procedure for changing the set point of a system parameter as a function of the time that a selected target area is touched.
The industrial process control system in accordance with the present invention advantageously permi-ts a system operator to enter commands, requests, display information, and the like in a manner by which the touch-responsive command entry area is in spatial registration or juxtaposition with a visual symbol of the controlled device to which the command pertains. In this way, commands and the like can be easily entered with a lo~ error rate. The need for entry through a keyboard is minimi~ed and may be eliminated in some applications to provide efficient, high-level system control~

; - 5 -The possibility of mis-stri}ce on the screen is greatly recluced when compared to the possibility of mis-strike in conventiona].
keyboard entry systems.
DESCRIPTION OF THE FIGVRES
The above description, as well as the objects, features, and advantages of the present inven-tion will be more fully appreciated by reference to the following cletailed deseription of a presently preferred but nonetheless illustrative embodiment in aeordanee with the present in-vention when taken in conjunction with the accompanying drawings wherein;
FIG. 1 is an overall system view, in schematic form, of a contre]. system for controlling an industrial p.rocess in aecordanee with the present invention;
Fig. 2 is a diagram, in schema-tie block form, of an input/output interface for the system shown in FIG. l;
Fig. 3 is a pictorial perspeetive of a cathode ray tube display device with a light-transmitting touch-responsive panel overlying the screen of the CRT, the touch responsive panel being spaced somewha-t from the display screen of the CRT for purposes of clarity;
FIG. 4 is a sehematie representation of the organization of the display generation portion of the input/
output in-terfaee shown in FIG. 2;
FIG. 5 is a pictorial map, in perspective, keyed to FIGS. 7 - 12 showing the displays obtained in response to touching of seleeted target areas of the "INDEX" display of FIG. 7;
FIG. 6 is a pietorial represen-tation of a global display portion of an overall display;
FIG. 7 :is a pietorial representation of an exemplary -task specifie "INDEX" display;
FIG. 8 is a p:ietorial representation of a second pa~e of -the "INDEX" display of FIG. 7;
FIG. 9 is a pictoria:L representation of an exe~plary "PROCESS OVERVIEW" task specific display;
~ IG. 10 is a pict.orial representation of an exemplary "PROCESS CONTROL" task specific displa.y;
FIG. 11 ls a pictorial represen-t~tion of an exemplary "PROCESS GRAPHIC" task specific display for a process for removing sulfur from a feed fuel oil;
FIG. 12 is a pic-torial representation of a second page of the "PROCESS GRAPHIC" display of FIG. 11;
FIG. 13 is a pictorial representation of an exemplary "BURNER AREA" task specific display, FIG. 14 is a pictorial representation of an exemplary "AREA SUMMARY" display;
FIG. 15 is a pictorial representation of an exempIary "ALARM SUMMARY" display;
FIG. 16 is a flow diagram representing an instruction set for entering digital-type commands; and FIG. 17 :is a flow diagram representing an instruction set for entering analog-type commands for iricrementing or decrementing an analog set point.
DESCRIPTION OF THE PREFERRED EMBODIMENT
.. . . . _ . . _ .. . . _ ...
An industrial control system in accordance with the present invention is shown in schematic form in FIG. 1 and includes a communications link CL having a plurality of remotely lo¢ated device controllers DCl, DC2, DC3, ...
DCn 1~ DCn connected thereto with each of the device cont.rollers DCn connected to one or more associated or corresponding con-trolled devices CDl, CD2, CD3, ...CD 1' CD such as, but not limited -to, various types of parameter sensors (tempera-ture, posi-tion pressure, and motion sensors, etc.) and various types of controlled devices ~motors, pumps, compressors, valves, solenoids, and relays, etc.)O A system ~ 7 -controlling interface 10 is a:lso connected to the communications link CL and provides a means by which signals (including information and control signals) may be extracted Erom or entered into the process control system. The system configuration shown in FIG. 1 is a distributed open loop or shared global buss-type; however, the inven-tion is equally suitable for application to central systems and central/
distributed hybrid configurations. The system of FIG. 1 is adapted for use in controlling an industrial process, e.g., the operation of an electrical power generation plant.
The organization of an e~emplary system control interface 10 is shown in FIG. 2 and includes a syste~ processor 12 connected -to the communications link CL through an appropriate input/output interface 14 and a memory 16 connected ~o the system processor 12. The memory 16 includes plural 1~ ~12, ...Mn which contain appropriate instruction sets and stored data for use in controlling -the system operation. ~ combined video output and tactile input device 18 is connected to the system processor 12 and functions as a man/machine in-terface as described more fully below with at least one auxiliary or alternate visual display device 20 also connected to the system processor 12. A printer 22 is connected to the visual output and tactile input device 18 to provide a hard copy of alpha-nurneric information or data such as alarm status information and a video copy unit 23 is also connected to the visual output and tac-tile input device 18 for providing a hard copy of the current video display. ln a similar manner, a chart recorder 24 is provided for obtaining a graphical output of a parameter~s) with respect to t:ime. In addition, a keyboard 26 is provided for au~iliary input of alpha-numeric data as described below.
The video display outpu-t and tactile input device 18 is shown in pictorial form in Li`IG. 3 and includes a cathode ~.
~ 8 --ray tube (CRT) having a conventional display screen 18a or surface and a touch-responsive panel. 18b that overlies the display screen. While not specifically shown in FlG. 3, the CRT is connected to the necessary structure and circuitry for the generation of full-color displays as described more fully below. The -touch-responsive device 18b preferably ta~es the form of a light transmitting (preferably transparent) panel that is placed over and overlies the display screen 18a of the CRT and conforms closely to the display surface of the CRT. The touch-responsive panel 18b, for e~ample, may be a flexible, transparent sheet-like panel fabricated from an insulating material such as MYL~R with a light-transmitting conductive coating deposited thereon of uniform resistivity. Plural electrodes (not shown) are deposited or otherwise formed along the horizontal and vertical edges of the touch-responsive panel and connec-ted to a power supply(s) to develop perpendicular elec-tric fields across the conductive coating so that when a surEace portion thereof is touched by a human operator, a signal is derived from the various electrodes which can be decoded or otherwi.se discriminated to provide the coordinates (X,Y) of the touched area. The touch-responsive panel may also take the form of a plurality of spaced parallel conductive traces arranged in columns and perpendicular rows with these rows and columns separated by a suitably apertured dielectric media to define a direct-contact switch matri~. The various rows and columns may be sequentially and synchronously scanned and electrical contact between a row(s) and a column(s) de-tected as a touch and these contact areas when correlated with the scanning information, providing the coordinates (X,Y) that indicate the location of the touched area on the display~ For example, as shown i.n ~IG. 3, the symbol of a control valve CV can be graphicall~ represen-ted on the CRT screen~ The symbol CV

occupies a corresponding surface area CV' of the touch-responsive panel 18b with -this area being identi~ied along -the X-axis tabsclssa) between the coordinates xl and x2 and along the Y-a~is (ordinate) be-tween the coordinates Yl, and Y2. Thus, if a human operator -touches the touch-responsive panel 18b at a position (X,Y) within the control valve CV' "target" area (that is, x1<X<x2 and Y1~Y<y2)~ the touch or "hit" will be within the area de~ined by the symbolically represented control valve CV. As explained in more detail below, this coordinate information (X,Y) can be employed by the system processor 12 to provide command inpu-ts to the system to effect a change in the control valve operation.
In the preferred embodiment, the system of FIGS. 1 - 3 can be utilized to permit the system opera-tor to call-up selected dlsplays as well as effect control of the system. The manner in which the system can be used for display call-up can be apprecia-ted from a consideration of the system architecture shown in FIG. 4. When an area of the touch-responsive panel 13a tx,Y) that corresponds to a predetermined graphical display is con-tacted, the coordina-tes of the "hit" are formatted at 23 and inputted to the display processor 30 which, in the case of the preferred embodiment, is an INTEL 8036 microprocessor with an associa-ted clock 32 and support integrated circuits (not shown). The processor 30, operating under the control of an instruction set 34 that evaluates the touched target, assesses the formatted X, Y
coordinate information to provide an X, Y display-label look-up pointer, symbolically represented at 36. The pointer 36 is used to designate or address the X, Y display-label table 33 which then provides an address te.g. "IND~X") to the d:isplay look-up table 40. The so-addressed display sub-routine ti.e.
"INDEX") is then provided -to a disp]ay generator 42 which generates -the called up display. In addition, a "HIT"

indicator display generator 4~ uses the formatted coordina-te information (X,Y) to generate a small cross s~mbol "-~" so that -the system operator(s) will always be informed of the last target area touched.
An exemplary process for control by the industrial process control system of FIG. 1 involves -the removal of sulfur from sulfur-containing fuel oil prior to using the so--treated oil to fire a conventional steam generator; it being understood the described process is merely representative~ Selec~ed overall displays associated with this process and suitable for use in demonstrating the present invention are shown in FIGS. 6 - 12. E~ch overall display includes -two portions:
a lower global display portion and an upper task-specific portion. FIG. 6 illustrates the global display, which is common to all of the displays, and shows a hori~ontal row of hollow, labelled target rectangles for effecting an input into the system. Exemplary touch-responsive rectangles include "INDEX", "ALARMS", "ALT" (an abbreviation for 'alternate'), "CLEAR", "PAGE", ''BACK'I, "ALM SUM" (an abbxeviation for 'alarm summary'), "RETURN", "COPY", and "EXE" (an abbreviation for 'execute').
The ''INDEXI' target is used to call-up the first page of a multi-page 'index' file; the "Al,A~MS" target is used to acknowledge all unacknowledged alarms on a currently displayed page of the 'alarm summary' file (described in more de-tail below); the "ALT" target is used to control the alternate display 20 of FIG. 2; the ''CLEAR'I target is used to clear (that is, remo~e) the current display on the screen;
the "PAGE" target is used to increment by one the page of the currently displayed file; -the "BACK" target is used -to decrement by one the page of the curren-tly displayed file;
the "ALM SUM" target is used to call-up -the first page of the 'alarm summaxy' file; the "RETURN" target is used to return the clisplay to the first page of the last successive display from an "N" deep display stack; the"COPY" target is used to actuate the prin-ter ~2 of FIG~ 2 to pro~7ide a hard copy of -the display; and the "EXE" target is used in -the en-try of two-step commands as described more fully below.
Of the above target areas of the global display, -the "INDEX", "ALA~S", "~LM SUM", "~LT", and the "E~E" targe-ts are discussed more fully below in connection wi-th the ~arious task-specific displays.
Touching the "INDEX" target of the global display causes formatted coordinate informat:ion (X,Y) identifying the touched area to be provided to the system processor 30 of FIG. ~. These coordinates are then used to generate a loo]c-up pointer 36 for appropriate display la~el (IN~EX) in the display table loo~-up table 38 with the so-looked up label used to address the appropriate set of display-generation instructions (INDEX) in the instruction table 40. These instructions then are provided to the display genera-tor 42 which then provided ths requested display (INDEX) on the cathode ray tube screen l~a~ In addition, the indicia display generator ~4 uses the formatted coordinate information to display a cross symbol "+" in ~he touchec~ area. In this way, the system operator(s) will always be informed of the last target area touched on the touch-responsive panel 18b.
The first page of the 'index' file called-up in response to touching the "INDEX" target of the global display is shown in FIG. 7 and, as shown therein, includes a plurality of labelled target rectangles. An exemplary second page oE
the 'index' file is shown in FIG. 8 and, as in the case of the fiLst page shown in FIG. 7, also includes a plurality of labelled target rectangles. The second page of the 'index' display is accessed by touching the "PAGE" target of the global display to cause -the display to increment one page in the 'index' file. Preferably, the pages of -the 'index' file, as well as the other display files di.scussed below, are looped end-to-s-tar-t so that incrementing past the last page of -the display will cause the display to yo to -the first page of the file~
A.s shown in FIG. 7, the lower portion of the 'index' display includes the following target areas: "CHART RECORDER
SEL" which permits selec-tlve operation of the chart .recorder 24 shown in FIG. 2 to provide a graphical record of the change in a selected parameter with respect to time, and a ~'SYSTEM
CONFIG" target which calls-up the first page of a 'system configuration' flle. The "ENTER TIME" and "ENTER DAY" target areas permit entry and updating of time and date data showr on the lower right~hand side of the displays of FIGS. 6 -12. The time and date information is entered using a two-step entry p.rocedure. For example, to enter or update the time, the "ENTER TIME" target is -touched and the appropriate time information is entered through the conventional keyboard 26 (FIG~ 2~ and thereafter the return key of the keyboard is depressed to effect entry of the time information. In a similar manner, the date information is entered. The "VIDEO
TREND" and "VIDEO TREND GROUP" target areas call-up historical information in graphical form from these files while the "REMOI'E STATUS" target area calls-up the 'remote status' file with informa-tion as to the various remote devices and their respective device controllers. The upper portion of the first page of the 'index' file includes target areas that permit the system operator to select speclfic files relating to the controlled process (in this case, a system for desulfurizing fuel oil). The operator may select -the first page of a 'plant overview' file, a 'process graphic' file, a 'log' file, and an 'area surnrnary' file for various portions of the specific process incl.uding the "PLANT", the "BURNER", and t.he "DESUL,FUR"

porti.on of the process~
A descriptlon of al.l of the files available -through the first and second pages of the Ir~DEx display of FIGS. 7 and 8 is not necessary to a full unders-tandlng of the presen-t inven-tion, and, accordingly, a description and discussion of only some of the files is provided with this selected description being sufficient to provide an understanding of -the present invention. The relationship of the various display files described below to t.he target areas of the first page of the 'inde~' file may be best appreciated by a consideration of -the display map shown in FIG. 5. The touching of the "PLA~lT
OVERVIEW" target for either the "PLANT", the "BURNER", or the "DESUL,FUR" portion of the process will bring up the first page of the so-reques-ted file with the display having the format shown in FIG. 9. This display includes a plurality (e.g. four) of labelled rectangles each of which include a plurality of bar graphs (Gl - G83 distribu-ted along a horizontal line in each rectangle. The various bar graphs (Gl - G8) in each of the labelled rectangles represent a selected parameter including an analog parameter (e.g., the deviation of a measured value from a set point or the relative position of an adjustable controlled device) or a digital parameter (e.g., the open or closed position of a valve).
Preferably -the bar graphs Gl - G8 are colored differently rom one another, and, if desired displayed a-t different brightness levels. Also the display brightness of some of the bar graphs, viz., those that are in an alarm condition, can cycle between two different brightness levels to provide a blinking or flashing effect.
Each of the labelled rectangles of FIG. 9 constitutes a target area for calling up another display. Thus, if the system ope:rator(s) requires additional informa-tion regarding the parameters of one of the "LABEL-2" bar-graph targe-t 5 ~

D~ ~

rectangles of FIG. 9, he merely touches that bar-graph rectangle to call-up the appropria-te 'process control' file having the format shown in FIG. 10.
The 'process control' file of FIG. 10 includes five sets of ver-tically aligned and labelled bar graphs wi-th each set including three individual bar graphs G'l - G'3 in a slde-by-side relationship. In addition, two push-but-ton target areas are provided on each side of the bar graph sets with -the left-hand push button area PBl representing ON/OFF control and the right-hand push button area PBZ representing a sys-tem safety control including an "A~ED" target area and a "TRIPPED"
target area. The bar graph sets of FIG. 10 each represent the output of a control loop. In the representative bar graph groups of FIG. 10, each left-hand bar graph G'l represents the magnitude of the measured value of a selected parameter, the intermediate bar graph G'2 represents the magnitude of the desired set point for that measured parameter, and the right-hand bar graph represents the operative position of an associated controlled device. For example, the right-hand bar graph G'3 can represent the analog position of a valve as a function of the height of the bar graph G'3. Beneath the various bar graph sets of F'IG. 10, various control information is provided including quantitative alpha-numeric information as to the set point and measured value of a parameter and an indication of the status of the respective PID (Proportional-Integral-Differential) control loop, that is, whether or not the associated PID loop is under the control of the system operator (e.g. manual control indications) or responsive to the output of another loop (e.g. cascade indications).

The touch-responsive panel l~b and the 'procass control' display oE ~IG. 10 can be used to efPect entry of commands of both a digital and analog na-ture. ~or example, ' - 15 -digital-type commands may be entered by touchiny the "START"
-target rectangle on the lef-t-hand side of the display of FIG. 10. Appropriate coordlnate ~X,Y) information in formatted form is presented to the processor 30 (FIG. 4) which then evaluates the coordinate infoxmation to generate an appropriate STA~T-command. Thereafter, the "EXE" target is touched to provide the actual START control signal to the appropriate controlled devicc (e.g. a pump). In a like manner, touching the STOP rectangle causes a STOP command to be generated with subsequent touching of the "EXE" -target causing the STOP
control signal to be provided to the controlled device. When the contro]led device responds to the control signal (i.e., by STARTING or STOPPING) that response then causes the appropriately -touched target rectangle to change to indica-te -the controlled device's response. Such changes may include, e.g., changes in illumination intensity, color, or the like, to indicate the correct "ON" or "OFF" status. An exemplary flow diagram representing an instruction set for effecting the above-described start/stop digital-type command signal entry and subsequent change in the controlled device's displayed symbol is shown in FIG. 16. In a similar manner, the safety-system "ARMED" and "TRIPPED" targets shown :in the right-hand side of FIG. 10 can be actuated -to also cause digital-type command entries. In order to enter analog-type commands, such as changing the set point of selected parameter for one of the loops, the upper portion of the appropriate bar graph set or the other designated area, for example, the area ATA-I (Analog Target Area-Incremen-t) shown in -the dot-ted line illustration in FIG. 10 is touched. The coordinate information in formatted form is provided to the processor 30 (FIG. 4) which then continuously increases the set point toward a maximum value for as long as -the target area ATA-I
is touched. For example, briefly touchin~ the ATA^-I area of the set point bar graph G'2 will cause t.hat set point toincrease a small amount, and touching the saMe -target area ~A-I for a longer period of time will cause the set point to increase proportionally. I'he change in the set point will then cause a resultant increase in the vertical he:ic~h-t of the set point ba.r graph G'2. Conversely, the se-t point may be lowered by touching a designated area ATA-D (Analog Target ~rea-Decrement) as shown in dashed li.ne below the set point bar graph G'2 with the set point being continuously lowered toward a minimum value ox as long as the area ATA-D is touched. The change in the set point will then cause a resultant decrease in the vertical height of -the set point bar graph G'2. As can be appreciated, -the set point may be raised and lowered in a very simple manner by merely touching, for the requlred amount of time, the appropriate -target area ATA-I or ATA-D with the requested change in the set point being visually displayed to the system oparator by the associated graph G'2 and the change in the measured value thereafter being i:ndicated by the associated graph G'l. An exemplary flow diagram representing an instruction set for effecting the above-described increment/decrement analog-type command signal entry and the subsequent change in -the set point is shown in FIG. 17. As can be appreciated by those skilled in the art, it is not necessary, as in the case of prior art systems, to manually enter alpha-numeric mnenomics identifying particular set points to be changed and then entering the new set point data. The display of FIG. 10 also includes, as shown therein, selected numerical information relating to the controlled. loop and other information indicating the particular mode the loop is operatincg in, as explained below.
The display of FIG. 10 is also usecl by the system operator(s) to chanye the overall control loop configuration.

Each of the PID .loops may be l~laced :in one o:f severaL operatiny rno~e~s incluc1i.ng a 'cascac~el or 'single~ mode and a 'marlu~l' or 'autoi mocle. Whi.le a cle~.ailed underst.aflcling of the operation of each mode is not essen-tial ro an unclerstanding of the present invention, t.he 'cascacle' mode permits a loop to receive, clS i-ts input, the output of another PID loop, ~hile the 'single' ~ode permits that sarne l.oop to operate in response to a precdetermined set poin-t, and the 'manual' mode permits the Joop ~.o operate as an open-loop follower without loop contxol, while the lauto' mocle permi-ts that same loop to opexa-te as a cl.osed loop. A particular PID loop can be switc~hed between the 'cascade' ancl Isingle' n10des by touching the target area DTA-C/S (Dis~ital Y'a.rget Area-Cascade/
Sirlgle] shown in dotted line illustration below the appropriate bar graphs. A small hit indicia "-~" will -then be displayed in the touchedtarget area ancl, if desired, -the brightness of -the touched l~TA-C/S target area can be rnade to cyclically vary between t.wo b:r:ightness levels to provide a flashi.ng or blinking effect. 'l'hereafter, the operator touches -the '~,XE"
~0 target of -the global display t.o enter the cornmand~ ln response thereto, the selected PID loop is then changed from its present mode (e.g., the 'cascade' mode) to the other available rnode (e.g., the '.sinyle' moc1e). In a li.ke manner, the system operator can switch a selectecl PID loop bet~eerl the 'rnanual' and 'auto' modes by touching the DTA-M/A (Di.gital Target. Area-Manua:L/Auto) under the appropriate bar graph set. A hi-t indicia ~ will then be displayed i.n the touched -target area and thereaEter, the operator touches the "EXE" targe-t of the globa:L di.splay 1:.o ente:r the command; the selectecl PID loop being then placed in the desired mode (e.g., manual or auto).
As can ~e appreci.ated from the fo:regoincJ desc:rip-ti.on, -c.ouching a "PLAN'r OVERVIEW" target- area of the 'inde~' dlsplay of lIG. 7 calls~-up the cli,splay of EIG. 9 W~liCh/ .ir~ turn, _ J~ .

permits -the ca~ up of lhe 'process control' display of Fl~. 10 which t:hen permits both digital. and analog ~ntry to effect process conL~ol changes wi.th -the so-requested chdnge~
being di.sp]ayed on the CRT d:isplay screen 1$R~
In a manner similar to -the Eunction of -the "~-~L~NI' OVERVIEW" target a:rea described above the "PROCESS GRAP~IIC"
taryet are~s of -the 'index' di play of FIG. 7 will call-up graphical representati.ons of the process. lor exarnple tollching the "PROCESS GRAP~-IIC" target area -~or the "DESULE~UR"
porti.on of the 'index' display will call-up the first page of a graphic displa~ file as shown in F:[G. 11 with the second page of the file (FIC 12) available for display by touchi.ng the "PAGE" target area o the global display.
The exemplary process shown in FIGS. 11 and 12 removes sulfllr from input fuel oil by mixiny the fuel oil with hydrogen gas heating the fuel oil and hydroqen Qlixture and then passing the so-heatecllllixture over a ca-talyst bed where ~.he hydrogen combines with -the sulfur in the fuel oil to form hydrogen sul~ide gas and the clesixed desulfured ~uel oil. As shown in FIG. 11 the con-trolled devices for effecting the desulfuri~ation of the fuel oil include a feed pump 1.00 which receives Euel oil from an input :Line :I.02 and del.iv~rs the fuel oil under pressure alonc~ l:ine 104 throu~h a f.Low meter 106 a flow contcol valve 108 alld a safety valve 110.
Hydrogen gas is provided along ].ine 112 and is mixed with the feed oil at junction 108. The temperature of -the ~as~oil mi.xture is measured by sensor 114 and tile mi.xture passed ~hrough a heat exchanger 116 where the mixture is preheated and then passed into a main hea-ter 118 throucJIl line 120 that includes a thermal sensor 122 and a control. valve 124. The heated mixture is passed to a cata:Lyst be~d 126 which contains a catalyst that causes the hydro~n gas to xeact with sulrur contained in the f~le.l o-i.l to form hyclrocJell sulE:ide gas and . - 19 ~

desu:lfured feed oil.. This rnixture is t:hen provide~ alony outlet li.ne 128 past pressure sensor 130 ancl temperatu~e sensor l32 to the heat exchanger :L:L6 where hea-t energy from the mi~ture is provided to the incoming fuel oil ancl hydrogen yas mixture. The somewhat ccoler rnixture i.s thell conducte alony li.ne 1.34 past temperature serlsv~ 136 -to the appara-tus shown on the seconcl paye of the 'process graph:ic display.
As described above the second paye of the 'process yraphi.c display (FIG. 12) is call.ed-up hy touching the PAGE tarc3et area of the global display. As shown ln F`IG~ 12~ the fuel oil mixture is passed to ano-ther hea-t exchanger 138 where additional heat energy is removed and pas-t a ternperature sensor - 140 to a gas/liquid separator 142. In the separator 142 the hydrogen sulfide gas i5 removed along line 144 thro~gh val.ve 146 with its flow rate and pressure being measured dt 148 and 150. The desulfured fuel oil is remo~ed along discharge line 152 through valve 156 with -the flow rate be:i.ng measured at 158. Also shown in FIG. 12 a llne 160 with pressure and fl.ow rate sensors 162 and 16~1 is provi.ded through which recycled process gas is provided to -the burners 1~6 of the heal:c-r 118 (I;lIG. 11) with the flow being c:on-trolled at valve 168.
A bar yraph rectangle is shown in the upper l.e:Et-hand side of FIG. ll and illustrates various parameters i.n bar graph form .ror the process shown in the remaininc3 portion of FIG. 11.. The bar graph area is also d target area and when -touched will call-up -the display of .FLG. lO to permit the system operator to effect. con-trol charlges with:in the system as clescribed above.
The operation of -the b~rner area of E~lG. 1.1 may be shown in greater cle-tail by depressiny the appropriat:e process graphic tar~Jct area fo.r the burrler on -the i.ll(k~`X pdyt' to provicle the clisp.l.ay shown i.n l;`:LG. 13. ille 'burller' displcly ~ 20 -includes the burners l66 whic~l se:Lectively rece~ve fuel gas along line 170, fuel oil along llne 172, pressurized steam along line 174, and fuel Eor the burner p:ilot along line 176.
The fuel lines 170 and 172 bo1-h lnclude control valving and pressure and temperature sensoxs that provide inputs to the associa-ted PID loops. The 'process controll clisp:l.ay of FIG~ 10 d:irectly corresponds wi-th the process graphics of FIGS. 11 - 13. More specifically, the push button control area PB1 on the left-hand side of F'IG. 10 controls the operation of the feed pump lQ0 of FIG. 11 with the three-bar graph set of FIGo 10 labelled 'product oil. feed' indicating the flow rate of the feed oil through line 104 in re:la~.lon - to the de.sired set point. The three-bar graph set of FIG~ 10 labelled 'burner ternperatu:re' :Lllustrat.es the measurecl temperature of the burners 166 of EIGS. 11 and 1~ in relationship to their deslred set poi.nt. The two three-bar graph sets labelled 'fuel oil pressure' and 'fuel gas pressure' graph:ical.ly illustrate the measured and set point val.ues for the fuel in ]ines :L70 and 172, respectively, of FIG~ 13 while the three-bar graph set labelled 'atomiza-tion steam pressure' indicates the pressure of the steam in line 174. As is ]cnvwn in the art, pressurized steam is introduced with fuel oil to assis-t in atomiziny the fuel oil. In -the norrnal operation of the burners 166, fuel gas .is a preferred fuel with fwel oil and associated steam being used when desired or when dictated by operating circumstances. As can be appreciated, commands inputted to the appropriate target areas oF
FIG. 10 directly control the various controJ. devices discussed above in connection wi.th ~IGS. 11 -- 1.3O
The "I.OG" target areas of the 'in~ex' Eile (~IG. 7) for the "PLAN'["', "BIJRNER", and "DESULE'UR" portions o~ the process provide a ti.me--tagged l.isting of events in the process. While a 'log' display has not been i:llustrated ,,, in the Figures, a typical 'log' d:isplay would i.noll.lde a listing o:F command changes and o-ther events along w.ith the -time and da-te -that thes~ changes or events occurred. If desi.red, a cumulat:ive log can be printed on the printer 22 (FIG. 2) at periodic interval.s, e~g., every hour-on-the-hou.r to provide an hlstvrical record of the process.
The "ARE~ SUMM~RY" target area of the lindex' file (FI~. 2) calls-up a display with a current status information of various of -the control loops and other paraMeters. An e~emplary 'area summary' display shown in FIG. 15 and as shown therei.n includes an alpha-numeric identifier for the con-trol.
loop or parameter, a short explanatory -title, the quantitative value, and the associated units.
The "ALARM SIJMMARY" t:axget area of the global display (FIG. 7) is used to call-up a listing oi thvse parame-ters or control loop outputs that are or have been in an alarr condition (that is, the measured val.ue is ei-ther above or below a predetertilirlec1 alarm limi.t). An exsmplary lalarrn summa.ry' display is shown in FIG. 15 and includes time and date informat;orl to indicate when the parti.cular parameter en-tered the alarin condltion, an alpha-numeric identifier, a short explanatory -title, the quanti.tative val.ue, an(l t~le associated units. Those part:icu.lar pararneters that are in alarm condi-tion in -the display of FlG. 15 may be highlighted for the operator's attention by ~arying their brightness le~el between two ~alues -to provi.de a blinking or flashirlg effect.
If the sys-tem operator wishes to acknowledge t.hose parameters in alarm condi.tion, he may touch the "ALARMS" target area oE the ylobal display to acknowledge the alarms and to cause the blinking or flashirlg to stop. :[n this way~ the operatur, by perloclically acknow:ledging ala.rms, can l~ent.ify -those parameters which most recently enter the a.l.arm cond:ition.
The "ALT" target of -the global display controls the display shown on the alte~rnate display device 20 ~IIG. 2). Fo.r e~ample, -touchirlg the "Al.T" target area and.
then touching the "COPY" target area will cause the prin-ter 22 (FIG. 2) to provide a hard copy of the display showrl on -the alterna-te clisplay device 20. Also, touching the "AI..'r' target area Eollowed by touching the targe-t areas "Cl.,E.~R", "PAGE", or "BACK" wouk~ cause these Eunc-tional responses -to take place on the al-terna-~e display~ Thus, by use o~ the "ALT" -target, differen-t displays can be called up for the visual display device 18a and the alternate display 20.
The pre~erred embodiment o:E the industrial process described above is merely exemplary of a wide varie-ty of - inciustrial. processes to which the indus-trial con-t.rol syste.rn of the present invention can be applied. As can be appreciated from the above, an indust.rial process control system in accordance w.ith the present invention permits a system operator -to effect quick and accurate control. of an entire system by merely touc:hing the appropriate area on a visual. display screen. The controlled devices of -the system and parameters ~0 are graphically and symbolically displayed on t:he screen ancl the command input device is spatially jux-taposed with the d:isplayed symbols so that command in~uts, including command inputs of both an analog and digital nature, can be easily and quickly ente:red into the system.
As will be apparent -to those skilled ln the art, various changes and modifications may be made to the present invention without departing from the spir.it and scope of -the invention as recited in the appended claims and their legal equivalent.

Claims (10)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A system for controlling an industrial process comprising:
a plurality of control means operable to effect changes in parameters of said process, said control means each operable to effect changes in a different one of said parameters;
a cathode ray tube; and computer means to simultaneously define a plurality of target areas at different locations on the face of said cathode ray tube each corresponding to a different one of said process parameters, said computer means being responsive to said parameters in said process to control said cathode ray tube to display the status of said parameters at the corresponding target areas, said computer means being responsive to a finger touching of a screen of said cathode ray tube to generate coordinate signals representing the position of said finger on said face of said cathode ray tube and responsive to said coordinate signals representing a position in one of said target areas to cause the corresponding control means to effect a change in a corresponding parameter of said process, -the change being displayed by said cathode ray tube at the corresponding target area.

2. A control system for controlling an industrial process, said system comprising:
a plurality of controlled devices and associated device controllers for effecting control of process parameters including rate of flow of materials in said process, said controlled devices and associated device controllers interconnected through a communications link means to a control interface, said interface including a visual display means having a visual display surface associated therewith and means for simultaneously generating symbols thereon representative of a plurality of said process parameters;
a finger touch-responsive means overlying said display surface and through which said symbols are visible;
computer means defining target areas at each of said symbols, said computer means detecting the touching by a finger on said touch-responsive means and for generating coordinate signals in response thereto representing the position of the touch on said display surface, said computer means being responsive to the coordinate signals representing a position in any one of said target areas to generate a command signal effective to cause a change in the process parameter represented by the symbol at such target area, the change of said process parameter causing a change in the displayed symbol representative of such process parameter on said visual display screen.

3. A control system for controlling an industrial process, said system comprising:
a plurality of controlled devices and associated device controllers for effecting control of process parameters, said controlled devices and associated device controllers interconnected through a communications link means to a control interface, said interface including a visual display means having a visual display surface associated therewith and means for generating symbols displayed simultaneously thereon representative of different process parameters of the system, said symbols each having a displayed analog characteristic representing the value of an associated process parameter;
a touch-responsive means overlying said display surface and through which said symbols are visible;
means for detecting the touching of selected target areas on said touch-responsive means corresponding to said displayed symbols, said target areas including a first area located at each symbol for incrementing the associated parameter and a second area located at each symbol separate from said first area for decrementing the associated parameter; and means for generating a signal in response to the touching of said first area and another signal in response to the touching of said second area, said first signal effective to increment the associated process parameter and the second signal effective to decrement the associated process parameter, the change in said process parameter causing a change in the analog characteristic of the corresponding displayed symbol on said visual display surface.

4. A control system for controlling an industrial process system, including:
a plurality of controlled devices and associated device controllers for effecting control of process parameters, said controlled devices and associated device controllers interconnected through a communications link means to a control interface, said interface including a visual display means having a visual display surface associated therewith and means for generating symbols thereon representative of the system process parameters;
a touch-responsive means overlying said display surface and through which said symbols are visible and means for detecting the touching of selected surface areas on said touch-responsive means corresponding to a selected displayed symbol representing an associated parameter, said selected areas including at least a first area for incrementing the associated parameter and at least a second area for decrementing the associated parameter;
means for generating a first signal in response to touching the first area and a second signal in response to touching the second area, said first and second signals varying as a function of the time that said first or second respective area is touched, said first signal effective to increment the associated process parameter as a function of the time that the first area is touched and said second signal effective to decrement the associated process parameter as a function of the time that the second area is touched;
the change in the process parameter in response to said signals causing a change in said selected display symbol on said display screen;
said first and second areas being linearly displaced from one another along a line, said symbol being displayed linearly therebetween and increasing lengthwise in response to said first signal and decreasing lengthwise in response to said second signal.

5. A control system for controlling an industrial process, said control system comprising:

(claim 5 cont'd) a plurality of controlled devices and associated device controllers for effecting control of said controlled devices, at least one of said controlled devices having operating states consisting of a first state and a second state, said controlled devices controlling parameters of said process including the flow of materials in said industrial process;
said controlled devices and associated device controllers interconnected through a communications link means to a control interface, said interface including a visual display means having a visual display surface associated therewith and means for generating symbols simultaneously on said visual display surface at different locations on said display surface representative of said controlled devices;
a finger touch-responsive means overlying said visual display surface and through which said displayed symbols are visible;
computer means defining a plurality of target areas on said display surface with at least one target area at each of said symbols;
said computer means detecting the touching by a finger on said touch-responsive means and generate coordinate signals representing the position of the touch on said display surface, said computer means being responsive to said coordinate signals representing a position in any one of said target areas to cause a change in the controlled device represented by the symbol at such target area, said target areas including at least one first area at one of said symbols representative of a first operating state of the corresponding controlled device represented by said one of said symbols and at least one second area representative of a second operating state of said corresponding controlled device;

said computer means generating a first control signal in response to said coordinate signals representing a position in said first area and a second control signal in response to said coordinate signals representing a position in said second area, said first control signal effective to cause said corresponding controlled device to enter its first operating state, and said second control signal effective to cause said corresponding controlled device to enter its second operating state, the change in operating state of said corresponding controlled device causing a change in said one of said symbols on said visual display surface.

6. A control system for controlling an industrial process, said control system comprising:
a plurality of controlled devices and associated device controllers for effecting control of said controlled devices, said controlled devices being proportionally operable through an operating range between first and second operating states;
said controlled devices and associated device controllers interconnected through a communications link means to a control interface, said interface including a visual display means having a visual display surface associated therewith and means for simultaneously generating symbols on said display surface representative of said controlled devices, said symbols each including a displayed analog characteristic representing the proportional state of the controlled device represented thereby;
a touch-responsive means overlying said display surface and through which said displayed symbols are visible;
means for detecting the touching of selected areas of said touch-responsive means corresponding to displayed symbols on said visual display surface including at least one first area located at each symbol and at least one second area located at each symbol; 29 means for generating a first control signal in response to the touching of said first area and for generating a second control signal in response to the touching of said second area, said first control signal effective to cause the controlled device represented by the corresponding symbol to move toward said first operating state and said second control signal effective to cause the controlled device represented by the corresponding symbol to move toward said second operating state, the response of the controlled device being displayed on said visual display screen as the analog characteristic of the corresponding symbol.

7. A control system for controlling an industrial process as claimed in claim 6 wherein:
said means for generating said control signals generates control signals proportional to the time that a selected area is touched.

8. A control system for controlling an industrial process, said control system comprising:
a plurality of process control loops each of which includes a controlled device and associated device controller for effecting control of process parameters, each of said process control loops having a first operating mode or a second mode, said process parameters including the flow of materials in said process;
said process control loops interconnected through a communications link means to a control interface, said interface including a visual display means having a visual display surface associated therewith and means for generating symbols on said visual display surface representative of said process control loops;

(claim 8 cont'd) a finger touch responsive means overlying said visual display surface and through which said displayed symbols are visible;
computer means for detecting the touching of said touch-responsive means by a finger to generate coordinate signals representing the position of the touch on said visual display surface, and responsive to said coordinate signals representing a position within a plurality of selected areas of said touch-responsive means corresponding to said displayed symbols on said visual display surface, each selected area being positioned at its corresponding displayed symbol, said selected areas including at least one first area at each of said symbols corresponding to the first operating mode of the process control loop represented by such symbol and at least one second area at each of said symbols corresponding to a second operating mode of the process control loop;
said computer means generating a first control signal in response to said coordinate signals representing a position in one of said first areas, and a second control signal in response to said coordinate signals representing a position in one of said second areas, said first signal effective to cause the corresponding process control loop to enter the first operating mode and said second signal effective to cause the corresponding process control loop to enter tile second operating mode, the change in operating mode of the process control loop causing a change in the corresponding symbol displayed on said visual display surface.

9. A control system for controlling an industrial process as claimed in claim 6 wherein the first area and the second area located at each symbol are linearly displaced from one another along a line, the corresponding symbol being displayed linearly therebetween and increasing lengthwise in response to said first control signal and decreasing lengthwise in response to said second control signal.

10. A control system as claimed in claim 6 wherein said at least one of said controlled devices controls a process parameter in accordance with a set point applied to the associated device controller, the displayed symbol representing said at least one of said controlled devices including a second displayed analog characteristic representing the value of said process parameter and a third displayed analog characteristic representing the set point applied to the associated device controller.