CA2201287A1

CA2201287A1 - Control system for a packaging machine

Info

Publication number: CA2201287A1
Application number: CA002201287A
Authority: CA
Inventors: Arde Kirka; Anders Ek; Johan Hegardt; Robert Massey; Olof Stark; Gunnar Drevfors; Ashok Singh
Original assignee: Individual
Current assignee: Tetra Laval Holdings and Finance SA
Priority date: 1994-09-28
Filing date: 1995-09-11
Publication date: 1996-04-04
Also published as: FI971704A0; EP0784568A2; JP4053086B2; DE69517697D1; US5706627A; FI971704A; EP0784568B1; BR9509060A; MX9702346A; DE69517697T2; EP0784568A4; JPH10507724A; US5966897A; NO315416B1; WO1996009970A1; NO972651D0; NO972651L; AU3509195A

Abstract

A packaging machine (20) under control of an electronic control system includes a plurality of servo driven packaging stations (45, 50, and 55) which are driven by one or more servomotors (170) to fill and seal a carton is forth. A plurality of servo amplifiers (160) are connected to the servomotors to control the rotational movement of the servomotors thereby to effect control of the motion of the various components associated with each of the packaging stations. The packaging machine further includes at least two programmable devices connected for communication over a common bus (270). A
programmable axis manager (PAM) (90) is connected to control the plurality of servo amplifiers (160) and, thus, the motion profiles of the servomotors and components of the respective processing station. A programmable logic controller (PLC) (80) is connected to receive and transmit input/output signals associated with the plurality of packaging stations. The PAM and the PLC communicate data variable values over the common bus using predetermined fingerprints assigned to each variable value. Use of the fingerprint/variable value protocol allows high speed communication between the PLC and PAM thereby allowing the PLC and PAM to be viewed as a single control unit.

Description

W09~'03~70 ,~tJ t 2 ~ 7 PCT~S95111443 CONTROL ~Y~-L`-I FOR A P~CR~TNG ~AC~TN~
CROSS~ R~NCE TO RELATED APPT~TCATTONS
This application is a continuation-in-part of U.S.
Serial No. 08/190,546, filed February 2, 1994.

TECHNICAL FT~r.n The present invention relates to a control system for a packaging machine. More specifically, the present invention relates to a control system that utilizes a programmable logic controller and a programmable axis manager that communicate through a high speed communication interface.

RA~K~ROUND
Packaging m~chin~?s are known that integrate the various components 10 necessary to fill and seal a cont~in~r into a single m~chine unit. This p~ck~ging process, generally stated, includes feeding carton blanks into the m~r.hine, sealing the bottom of the cartons, filling the cartons with the desired coll~ell~, sealing the tops of the cartons, and then off loading the filled cartons for shipping. The motion and I/O control of the p~r.k~ginp machine may be undertaken by an electronic control system.

WO9~9~70220 1 28~ PCTIUS9~/11443 ~

Traditionally, control systems for p~cl~ging m~hines have utilized program~able logic controllers (PLC) to effect both motion and I/O control. PLC
system architecture, however, is principally directed to I/O conkol and has onlylimited value as an axis controller. Such a system is described in U.S. Patent No.
55,177,930, issued January 12, 1993. As illustrated in the '930 Patent, a single PLC
is utilized to control both the motion and the I/O.
Trends within the field of p~ck~ging m~r.hin~s point toward increasingly high capacity m~ehines int.?ntl~l for rapid, continuous filling and sealing of a very large number of identical or similar p~ck~ging containers, e.g., c~ nt~iners of the 10type intendecl for liquid contents such as milk, juice, and the like. One suchm~chine is disclosed in U.S.S.N. 08/190,546, filed February 2, 1994, which is hereby incorporated by reference. The m~chine disclosed in the '546 application includes a plurality of processing stations, each station implementing one or more processes to form, fill, and seal the containers. Each of the processing stations is 5driven by one or more servomotors that drive the various components of each of the processing stations.
The increased throughput and decreased size requirements have increased the ~em~n~l~ that are placed on the control systems that are employed. As the number of axes increases, the cl~m~n~l~ on the speed of the control system response 2 oalso increases. The traditional single PLC control system is often inadequate to meet these speed requirements. Accordingly, a more sophisticated control system for a p~cL ~gin~ m~chine of the foregoing type is desirable.

~W096/09970 .;22d.1.2~7 PCT/US95/11443 SUl\II~ARY OF THEINVENTION
A p~ ging m~r,hine under control of an electronic control system is set forth. The p~,k~ging machine includes a plurality of servo driven p~c,k~ging stations that execute the processes required to fill and seal a carton. Each of the p~c~ging stations is driven by one or more servomotors associated therewith. A
plurality of servo amplifiers are connected to the servomotors to control the rotational movement of the servomotors thereby to effect control of the motion of the various components associated with each of the packaging stations. The p~ ging m~rhine further includes at least two programmable devices connected for communication over a common bus. A programmable axis manager (PAM)is connected to control the plurality of servo amplifiers and, thus, the motion profiles of the servomotors and components of the respective processing station. A
programmable logic controller (PLC) is connected to receive and transmit inputloutput signals associated with the plurality of p~r,k~gin~ stations. The PAM
and the PLC communicate data variable values over the common bus using predetermined fingt;l~linl~ assigned to each variable value. Use of the fin~ lhll/variable value protocol facilitates high speed communication between the PLC and PAM thereby allowing the PLC and PAM to be viewed as a single control unit.
2 0 In accordance with one embodiment ofthe p~ ping m~hine, the PLC and PAM may communicate with one another by accessing a common set of memory locations that are, for example, disposed in dual port memory located in the PAMand which are accessible by the PLC over the communication bus. Selected wo ~03~70 ~ ~ 2 2 0 1 ~ ~3 / PCT/US95/11443 ~

memory locations within the common set of memory locations have predet~rrnin~d functions, such as fl~g~ing a message from the PLC or PAM, identifying where fingerprint and variable data are stored for colll",u"ication, and acknowledgingreceipt of the fing~",filll and variable data.
In acco~ ulce with further aspects of the p~ gin~ m~hinP, the PAM and the PLC may effect initialization through an initialization sequence that facilitates an efficient software development platform. Such initialization may be effected,for example, by Pxch~nging selected CRC values between the PAM and PLC, the selected CRC values identifying which variables are to be used in communications0 between the PAM and PLC at runtime. The PLC and PAM may then assign the predetertnin~d fing~".fi~L~ corresponding to the selected CRC values and communicate the fingerprint values to one another. The predetPrrnin~d finge~
are subsequently used to identify each variable in subsequent communications between the PLC and PAM at runtime. Such variables may include variables that allow the PLC to instruct the PAM to execute a production cycle, to instruct certain mech~ni~m~ to go to a pre~let~rrnined position, etc. Such variables may further include variables that allow the PAM to inform the PLC of the presence of power at the various processing stations and, further, inform the PLC of excessive torque requirements from the servomotors indicative of system errors.

~ wo g~ 70 2 2 0 l ~ ~ 7 PCT/US95/11443 BRII~F DESCRIPTION OF THE DRAWINGS
FIGS. lA and lB are sçhem~tic illustrations of a paçk~ging m~r.hine including a plurality of processing stations that each include one or more servodriven mech~ni~m~.
FIG. 2 is a sc.hem~tic block diagram illustrating one embodiment of the control system for controlling the operation of the parl~ging machine illustrated in FIGs. lA and lB.
FIGs. 3 and 4 are sçhem~tic block diagrams of a programmable axis manager including a VME bus interface.
FIG. 5 is a schem~tic block diagram of one embodiment of the servo amplifier that may be used in the control system of FIG. 2.
FIG. 6 is a flow ~ gr~m illustrating the execution of a plurality of tasks by the ha~.lw~e and software of the PLC and PAM.
FIG. 7 illustrates one embodiment of the synchronization task of FIG. 6.
FIG. 8 illustrates one embodiment for the initi~ tion task of FIG. 6.
FIG. 9 is a flow (li~gr~m illustrating operation of the PLC in its run mode.
FIG. 10 is a block diagram illustrating a traditional data tr~n~mi~ion and an exemplary fin~ hll/variable value tr~n.~mi~ )n.
FIG. 11 illustrates one method of OL~ ni7.il~p: the memory locations of the 2 o dual-port memory of the PAM.
FIG. 12 is a flow diagram illustrating one embodiment of the PLC/PAM
variable communications.

Wosç,0~970 22012~ PCT/US95/11443 ~

FIG. 13 is a flow diagram i~ dlillg the tasks p~.r~,l.led by the PAM and the PLC when the PAM transmits data to the PLC.
FIG. 14 is a flow (li~grAm illustrating the tasks ~elrolllled by the PLC and PAM when the PLC lldllslniL~ a variable to the PAM.
FIGs. 15-41 are exemplary motion profiles that may be executed by the meçh~ni~m~ ofthe various package processing stations under control ofthe controlsystem of FIG. 2.
FIGs. 42 and 43 illustrate one algorithm for slip correction.
FIGs. 44 and 45 illustrate a modular circuit configuration that may be used in connection with each a~p~d~us of each processing station.

~ w0~0~370 27Q1 2~7 PCI/US95/11443 DET~TT,~.l) DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGs. lA and lB are schPm~tic illustrations of a p~rl~ging m~rhine system such as the one disclosed in the aforementione~l '546 application. The p~cl~gingsystem, shown generally at 20, includes an upper endless belt conveyor 25 and a lower endless belt conveyor 30. The upper endless belt conveyor 25 is driven by a pair of pulley wheels 35 that, for ç~mple, are driven by one or more servomotors.
The lower endless belt conveyor 30 is also driven by a pair of pulleys 40 that, for example, may be servomotor driven. The conveyors may be constructed in accordance with the te~rhings of U.S.S.N. 08/282,981, filed July 29, 1994, 1 o incorporated herein by reference.
A plurality of processing stations 45, 50, and 55 are disposed about the periphery of the endless belt conveyors 25 and 30. The processing stations 45, 50, and 55 each have their respective mechanical components driven by one or more servomotors that control the motion profile of the station components.
The lower conveyor 30 may receive erected carton blanks at end 60 and transport the carton blanks to processing station 45. Processing station 45 may include a lifter mech~ni~m and a bottom sealer mech~ni~m The lifter mech~ni~m may be constructed in accordance with the te~ching~ of U.S.S.N. 08/315,410 (Attorney Docket No.10325US01; col~uldle Docket No. TRX-0043) entitled "Belt Driven Linear Transport Apparatus for a P~ in~ Machine", and U.S.S.N.
08/315,401 (Attorney DocketNo. 10602US01; Corporate DocketNo. TRX-0044) entitled "Lifter Meçh~ni~m Employing a Carton Gripper and Carton Bottom Seal Configuration for Same", both of which are filed on even date herewith. The WO ~ 702 ~ PCT/US95/11443 ~

bottom sealer m~ h~niem may be constructed in accordance with the te~r.hinge of U.S.S.N. 08/315,412 (Attorney Docket No. 10454US01; Co,~..dl~ Docket No.
TRX-0082), entitled "Ultrasonic Carton Sealer", which is likewise filed on even date herewith. Both the lifter mech~ni~m and the bottom sealer mech~niem are 5 driven by re~e-;live servomotors.
In operation, the lifter me~ h~niem transports the erected cartons in groups from the lower conveyor 30 to the upper conveyor 25. At the upper conveyor 25, the bottoms of the cartons are sealed, for example, with previously noted sealing a~dlus using ultrasonic energy.
1 0The upper COllv~;yOL 25 transports the cartons in the direction indicated by arrow 65 to processing station 50. Processing station 50 may include a fill lifter mech~niem, a plurality of filling nozzles respectively associated with each of the cartons, and a top sealer. The fill lifter may be constructed in accordance with the te~rhinge ofthe aforementioned application No. 08/315,410 (Attorney Docket No.
1510325US01; Corporate DocketNo. TRX-0043) and applicationNo. 08/315,401 (Attorney Docket No. 10602US01; Corporate Docket No. TRX-004), while the top sealer may be constructed in accordance with the te~chinge of the aforementioned applicationNo. 08/315,412 (Attorney DocketNo. 10454US01; Corporate Docket No. TRX-0082). At processing station 50, the fill lifter lifts the cartons to a 2 o position proximate the fill nozles and gradually lowers the cartons as product is dispensed into them. Once the cartons have been filled, the top sealer seals the carton into the f~mili~r gabled top configuration.

0 96/09970 ~2 ~ 7 PCTtUS95tll443 After the tops of the cartons have been sealed, the upper conveyor 25 transports the cartons in the direction of arrow 70 to proces~ing station 55.
Processing station 55 may include a bottom forming merh~ni~m and an outfeed mech~ni~m The bottom for~ning mech~ni~m, for example, may be constructed in accordance with the te~chin~ of U.S.S.N. (Attorney Docket No. 10599US01;
Corporate Docket No. TRX-0064), entitled "Vacuum Operated Bottom Former", filed on even date h~,~wilh, and the outfeed meçh~ni~m may be constructed in acco..lal~ce with the te~çhings of either U.S.S.N. 08/315,409 (Attorney Docket No.
10594US01; Corporate Docket No. TRX-0113), entitled "Apparatus for 1 0 Trdl~r~l.;ng Cont~iner.~ to a Moving Conveyor") or U.S.S.N. 08/315,404 (Attorney Docket No. 10610US01; Corporate Docket No. TRX-0118), likewise entitled "A~p~lus for Transferring C~ i to a Moving Conveyor", both of which are filed on even date herewith. At processing station 55, the bottom forming mech~ni~m forms the bottom of the cartons to allow them to sit plu~c~ly in an erect state. After the bottoms have been formed, the outfeed mech~ni~m transfers the cartons to a distribution system, shown here as a dual line conveyor 75. FIG.2 is a sçhem~tic block diagram illustrating one embodiment of a control system forcontrolling the operation of the p~k~gin~ m~hine illll~tr~te-1 in FIG. 1. The control system includes a PLC 80, an industrial PC 85, a PAM 90, and an I/O
2 o interface unit 95, all of which are disposed in a bus rack 100 for con~ ication with one another. The bus rack 100, may be a VME bus, a SIMATIC S5 bus, or any other bus that is capable of supporting multiple processors.

WO 9~ 0~70 ~ 2 br l 2 ~ ~ pcrluss5lll443 ~

As illustrated, the PLC 80 includes a ROM 105 and a RAM 110. The ROM
105 incl~ s the software that is required to program and run the PLC 80 and, forexample, may include E2 PROM for storing the ladder logic prog".."",i,~g and, aswill be described in detail below, the PLC communication program. The PLC 80 is in co,-""ul,ication with the I/O int~ ce unit 95 which receives and sends I/Osensor and control signals along lines 120 and 125. Additionally, the I/O interface unit 95 receives signals, such as keypresses, from an operator control panel 130along one or more lines 135. The industrial PC 85 is also connected for co,lln,ullication with the opeldLol control panel 130 which, for example, can send detailed graphic information to a display on the operator control panel 130 thatadvises the m~hine operator of the status of the m~t~hinP
The PAM 90 includes a ROM 140 and a RAM 145. The ROM 140 includes the programs nt-cçc~ry to operate and program the PAM 90 and, for example, may include E2 PROM for storing the user program. The PAM 90 further includes a dual port memory, shown here as DPRAM 150. The PLC 80 and PAM 90 may both access the memory locations in the DPRAM 150, the PLC 80 ~ccessing the DPRAM 15 along the VME bus.
The PAM 90 is connected for communication with a plurality of servo amplifiers 160 along one or more lines 165 which may constitute an optical ring 2 o network. The servo amplifiers 160, in turn, are each connected for control of a respective servomotor 170 along lines 180. The servomotors 170, in turn, are connected to drive, for exarnple, gear shafts 190, either directly or through a wo~6~70 ~ 2~7 PCT/US95/11443 ;~e~;Li~e gear box. The drive shafts 200, for example, each con~tit~lte one or more components of one of the processing stations 45, 50, and 55.
By way of example, the servo amplifiers 160 may each be a Model ST-l servomotor and the PAM 90 may be a programmable axes manager, both of which 5 are m~nllf~ctllred and available from Socapel. Similarly, by way of example, the PLC 80 may be a Model 9070 progr~mm~kle logic controller that is available from GE Fanuc.
In the case where one or more Model ST-ls are used to implement the system, the servomotors 170 may be used to sense and propagate I/O signals 10 through, for example, I/O int~rf~ce circuits 210. The status of sensor inputs as well asthecontrolof~r,tl~tingoutputstoandfromthe l/Ocircuit210arecl-"""ll"icated along the optical ring network.
A sçh~m~tic block ~ gr~m of one embodiment of a PAM 90 is set forth in FIG. 3. Central to the operation of the PAM 90, is a central processor 220 that, for example, may be an INTEL 80960 RISC processor. Programs and data for use by the central processor 220 are stored in a main memory 230. The main memory 230, as illustrated, may include EPROM, E2 PROM, DRAM, and/or SRAM memory.

The central processor 230 is in communication with several dirl~ lt 2 0 int~rf~e circuits. An optical ring interface circuit 240 is used to allow the central processor 220 to coll-lllunicate with the servo amplifiers 160 over the optical ring network lines 165. A serial int~rf~ce circuit 250 may be provided to allow connection between the PAM 90 and a t~rmin~l or a colll~uLel for application wo ~ 70 ~ 2 O 1 2 ~ ~ PCT/US95/11443 ~
tli~ nosi~ and debugging. A D/A convertor circuit 260 provides analog signals atlines 265 and 270 that may be used for monitoring or debugging purposes.
The central processor 220 connects to VME bus 270 using a PAM/VME
interface circuit 275, the details of which are shown in schem~tic form in FIG. 4.
A connector block 280 includes the connectors and drivers that are directly connPcte~l to VME bus rack 100. The interf~ce further includes a signal control and wait state generator 300, an address decoder 310, and the dual-port memory 150.
The PAM 90 fimction~ as a slave device on the VME bus 270. As such, the PAM 90 does not have direct access to the bus 270. Rather, all co~ ie~tion between the PAM 90 and the PLC 80 takes place through the dual-port memory 150 which is ~ccec~ihle by both the PAM 90 and the PLC 80. Access to the dual-port memory 150 over the VME bus 270 is controlled with the ~ t~nce of the signal control and wait state generator 300 and address decoder 310. Access by the central processor 220 to the dual-port memor.v 150 is controlled by the signals on the signal control lines 320, the address lines 330, and the data lines 340.
FIG. 5 is s~.hem~tic block diagram of one embodiment of a servo amplifier 160 that may be used with the PAM described above. In the illustrated block (li~gr~qm, the servo ~mplifier, has been functionally divided into software functions shown on side 350 and haldw~e functions shown on side 355. On the hardware side 355, the position and speed ofthe servomotor 160 is obtained by monitoring signals sent from a resolver 360 disposed on the shaft of the servomotor 170. These signals are supplied to a resolver hardware/software int~rf~e 365 that converts the signals into position and angular speed measurements. These measurements are WO 96109970 ~ ^Z 8 7 PCI/US9S/11443 sent to position/velocity controller 370 and a phase controller 375 software. The position/velocity controller 370 interf~ces with ramp generating software 380 and central unit software 390. The central unit software 390 receives motion profile information from the PAM 90 through a process interface 400. The central unit 5 software 390, in turn, sends the requisite motion profile data to the ramp genPr~ting software 380 and the position/velocity controller software 370. This data is ultimately sent as digital signals to a D/A convertor 410. The output of the D/A
convertor 410 is supplied through a s.l..llll;llg circuit 420 to a current controller 430 that, in turn, drives an inverter array 440 that supplies the n~cess~ry power signals to move the servomotor 170 to the desired position in accordance with the programmed motion profile. The central unit software 390 may also int~rf~e with a test board 450 that provides the n~cec~ry connections for a personal co~ ulel thereby allowing debugging and monitoring of the servomoamplifier 160. Faults are ~letecte-l by a fault detection circuit 460 and coll"nullicated to the PAM 90 through the central unit software 390 and the process interface 400. Such faults may then be ct ~ ~ "u~ icated to the PLC 80 over the VME bus 270, for example, in the manner described below.
The hardware and software of the PLC 80 and the PAM 90 execute a plurality of tasks, illustrated here in FIG. 6. In accordance with this embodiment, the PLC 80 and PAM 90 first execute a synchroni_ation task 470. During synchlolli~lion, the PLC 80 and PAM 90 advise one another that they are active (i.e., that they each have power supplied and have completed their own int~rn~l initial checks). After synchroni_ation, an initi~li7~tion task 475 is executed in WO 96/09970 ~ Z O 1 2 ~ 7 PCTIUS95/11443 .-, . , --which the PLC 80 and PAM 90 ~xch~nge cyclical re~-ln~ncy check values (CRC) and finge~ lL values for the data variables that will be collllllL~llicated between them at runtime. Once the CRC and fin~,elyl;llt values have been exchanged, the fin~ ,flllL values are used to exch~nge initial values for the variables that will be collllllullication between the PAM 90 and PLC 80 at runtime. This task is illustrated at block 480. After the colll.llullication fingtll,flllL and initial variable data values have been established and exch~nged, the PLC 80 enters a run mode 485 during which, for example, it executes its ladder logic processing and PLC/PAM communications program, the PAM 90 executing tasks under the direction of the PLC 80.
FIG. 7 illustrates one manner in which synch~ulli~Lion between the PLC
80 and PAM 80 may be executed. As illustrated, the PLC 80 first requests an active status signal from the PAM 90 at 495. The PLC 80 then waits a predetermined period of time for receipt of the active status signal. If the active status signal is not received within the pre~letermined period of time, the synchronization program flags an error to the main PLC program at 500 thereby preventing further operation of the system. If the PLC 80 receives the active status signal from the PAM within the pre~leterrnined period of time, the PLC 80 transmits its own active status signal to the PAM 90 which must be acknowledged by the PAM at 505 within a preclete~ined period of time. If the PAM 90 fails to acknowledge receipt of the PLC's active status signal, the synclllolli~Lion prograrn will flag an error to the system's software at 500. If the PAM 90 acknowledges ~ w0~ 970 2 7 0 ~ ~7 PCTnUS95/11443 receipt of the PLC active status signal within the precl~l~ ....i .~ed period of time, the cycle is again repeated.
Upon completion of the synchlolli~lion task 470, the initiali_ation task 475, shown here in FIG. 8,iS executed. During initi~li7~tion, the PLC 80 first sends 5 CRC values to the PAM 90 ofthe PAM variables that it wants c~."""~ ic~te~l from the PAM 90 during runtime. This is shown at block 5 l 5. The PAM 90 receives the CRC values and CO~ 'eS them at 520 to a software table in the PAM's memory and, based on that comparison, assigns fingc~fi~ values to each of the CRC values that were tr~n.~mitte~l by the PLC 80. The PAM 90 then ll~ls~lliL~ the fingcl~l;
values for each of the PAM variables back to the PLC 80 at 525. The PLC 80 stores these finge,~,;n~ values at 530 for later use during subsequent communication between the PLC and PAM at runtime.
After the PLC 80 has identified the PAM variables that it desires to use during runtime and has received the collc~onding fing~.~,;lll values, the PAM 90 sends CRC values to the PLC 80 at 535 of the PLC variables that it wants communicated from the PLC 80 during runtime. The PLC 80 compares these CRC
values to a table stored in its memory and assigns a finge,~l;l,l value to each CRC
value that it received as shown at 540. The PLC 80 then kansmits the fing~ ,fillt values co~,e~onding to each ofthe CRC values received from the PAM back to the 2 o PAM 90 at 545. The PAM stores the fin~,e,~,illl values for each PLC variable for later use during PLC/PAM co.~ .ic~fions at runtime as shown at 550. After the CRC values have been exch~n~e and the corresponding fingel~l;nL values have 2201 2~7 r WO 96/09970 PCT/US95/11443 ~

been ~ ne~1, the PLC 80 and PAM 90 exchange initial values for each of the variables that have been ~signPd a fingt;lpr"lL
FIG. 9 illuskates PLC operation at runtime when it is placed in the run mode. In the run mode, the PLC 80 executes several non-user defined tasks 560, 565, 570 and 580, which are part of the PLC's architect .re, as well as a user program, drsi~n~ted here at block 585. After enterin~ run mode at 560, the PLC
80 executes a series of housekeeping tasks at 565. The PLC 80 then reads and stores the real world inputs that are detectecl at the input ports of the PLC 80. Once the real world inputs have been stored, the PLC 80 executes the user program at 585 1 0 which, for example, includes ladder logic proce~in~ and PLC/PAM
cn" ., . .u~ic~tion~. After completing its tasks, the user program returns conkol to the non-user defined task at 575 which updates the PLC real world outputs based on data received from the ladder logic processing of the user program at 585. A
watchdog circuit is then updated at 580. A failure to update the watchdog circuit 1 5 within a predeterminP~l period of time will reset the PLC 80 and/or kigger an error signal that may be used to shut down the packaging m~r.hine.
FIG. l0 illustrates a comparison between a kaditional data tr~n~mi.~ion, shown here at 600, and the kr~n.cmi~ion of variable data as implemented in the p les~lllly disclosed system shown here at 6 l 0. In accordance with kaditional data 2 o k~n~mi~ions, the data packet includes a start byte 6 l 5 variable, identification bytes 620, data bytes 625, a CRC byte 635, and an end byte 635. The CRC byte is, for example, a check sum of the variable identification bytes 620 and data bytes 625.
The CRC byte 630 is calculated by the k~n~mitting station immediately before the ~ wo 96/09970 2 2 0 1 2 8 7 . ~1US95/1 1443 trAn~mitfing station sends the data trAn~mi~ion to a receiving station. The receiving station calculates its own CRC value and co~ ~es it to the CRC byte 630 that it received from the transmitting station to detPrmine whether there have been any tr~n~mi~ion errors. Such continuous calculation and re-calculation of the CRC byte 630, as well as the use of a start byte 615 and end byte 635, may wastevaluable system time and resources. Such waste may not be tolerable in a PLC/PAM system that controls a high speed p~ckAging machine that includes a substantial number of motion axes.
In contrast with the illustrated traditional data trAn~mi.~ion 600, the exchange of variable data between the PLC 80 and PAM 90 of the present system ensues via a pre~let~rmined variable fmg~ inl 640 which is followed by the variable value that is ~ d in one or more (usually one) data bytes 654. This protocol fAcilitAtes high speed co~ llllicAtion between the PLC 80 and the PAM
90 since it involves fewer trAn~mitted bytes and, further, does not require continuous calculation and re-calculation of the CRC byte 630. TncteAd, the variable fingt;l~,hlt of each variable that is to be commullicated between the PLC
80 and the PAM 90 has been predetermined prior to runtime, for example, in the initiAli7Ation task 475.
As previously noted, data trAn~mi~ion between the PAM 90 and the PLC
2 o 80 takes place through the dual-port memory 150. FIG. 11 illustrates one method of OlgAI ~ the memory locations of the dual-port memory 150.
In accordance with the illustrated memory ol~AI~ ion, the dual-port memory 150 includes a ll~lslllil memory area, shown generally at 660 and a receive -WO 9~ 09~70 ! PCT/US95/1 1443 memory area, shown generally at 670. The transmit memory area 660 includes a PLC transmit flag 675, a L~ llil address start location pointer 680, a PLC transmit flag acknowledges a location 685, and transmit data memory 690. Similarly, the receive memory area 670 inchl(les a PAM LldllSmi~ flag 695, a receive address start location pointer 700, and receive data memory 705.
FIG. 12 is a functional flow diagram of one method of implementing the PLC/PAM variable cr "l",ll"ications. The variable ct ",l~,l.llications task includes a periodic update of a collllllullications watchdog at 720. If this watchdog is allowed to time-out, the variable co~ ications program will flag a system error that may be used to shut down the p~cl~ging m~chine. After updating the communications watchdog, the PLC 80 checks the PAM transmit flag 695 in the receive memory area 660 of the PAM 90 at block 725 to ~lett?rmine whether the PAM has new data to Ll~lsnlil to the PLC 80. If the PAM transmit flag 695 is set, the fingt;l~lilll and PAM variable value are transferred from the PAM 90 to the PLC
80 as shown at 730.
After this transfer has occurred, the PLC 80 checks the PLC variable that is pointed to by a PLC variable pointer. If the PLC variable that is pointed to has changed, the fing~l~lh~l and the changed PLC variable value are sent to the PAM
90. A check is then made of the PLC variable pointer to cletermine whether the end of the PLC variable table has been reached. If the end of the table has been reached, the PLC/PAM variable c( l l ll ~ ications are termin~te~l and the PLC ladder logic program is allowed to continlle~l, or control of the PLC processor is returned to the PLC non-user program. If the end of the table has not been reached, the PLC

w0 9~ 70 2 2 0 1 2 ~ 1 PCT/US95111443 variable pointer is updated and the variable col,llllul~ications cycle is again executed.
FIG. 13 illu~Lldles a more detailed implement~tion of the data tr~n~mi~ion of a PAM variable. The PAM tasks are illustrated generally at 800, while the PLCtasks are illustrated generally at 810. The PLC tasks 800 and PAM tasks 810 are being run con~ lclllly by the PAM 80 and PAM 90 respectively.
With reference to the PAM tasks 800, the PAM 90 first reads the PAM
transmit flag 695 in the PAM dual-port memory 150. A set PAM transmit flag 695 indicates that the PLC 80 has failed to complete reading of the immediately prece.ling fing~l~lhll and variable value and, as such, the PAM 90 is not free to send a further fin~ lhlL and variable value. Accordingly, the PAM 90 waits untilthe PAM ll~lsll~il flag 695 is cleared. Once the PAM transmit flag 695 is cleared, the PAM 90 stores the start address location at the receive address start location pointer 700 in the transmit memory area 670 of the dual-port memory 150. The 1 5 value stored in the receive address start location pointer 700 points to the address at which the PAM 90 will store the finge~l;lll and variable value in the receivememory area 670 of the dual-port memory 150. After storing the start address location, the PAM 90 sends the fing~ l and variable value to the receive memory area 670 of the dual-port memory 150 beginning at the start address 2 o location identified by the PAM 90 in the pointer 700. Once the fingel~l;lll and variable value have been stored, the PAM 90 sets the PAM transmit flag 695 in the receive memory area 670 of the dual-port memory 150. The PAM 90 then returns, W096/09970 ;~;~ a l -~ 8 ~ PCT/US95/11443 ~

for example, to check for further PAM variables that must be sent by the PAM 90 to the PLC 80, or to read variables that have been ~ .ni~lecl from the PLC 80.
With respect to the PLC tasks 810, the PLC first reads the PAM transmit flag 695 in dual-port memory 150. If the PAM transmit flag 695 is not set, there 5 is no PAM variable data to be read by the PLC 180. If, however, the PAM l.,..~.c.,,il 695 flag is set, the PLC 80 gets the location of the finge.~ t and variable value from the location pointed to by the receive address start location pointer 700 in the receive memory area 670 ofthe dual-port memory 150. The PLC 80 acknowledges receipt of the fingerprint and variable value by clearing the PAM transmit flag 695.
The PLC 80 then returns from the tasks 810 to, for example, transmit its own variable data values, or read further PAM variable values.
FIG. 14 is a more iet~ile~ full ~ gr~m of the tasks that are executed by the PLC 80 and PAM 90 in l~ g a PLC variable from the PLC 80 to the PAM
90 PLC tasks are illustrated generally at 850 while the PAM tasks are generally 5 illustrated at 860.
With respect to the PLC tasks 850, the PLC 80 first reads the PLC transmit flag 675 from the dual port memory 150. If the PLC transmit flag 675 is set, the PAM 90 has failed to complete reception of the immediately prece~ling PLC
variable value that was sent. Accordingly, the PLC 80 does not attempt to send a 2 o further PLC variable.
Once the PLC transmit flag 675 has been cleared, the PLC 80 sets the PLC
transmit flag 675 in the transmit memory area 660 of the dual port memory 150.
A check is then made to det~rmine whether the PAM 90 has acknowledged the ~ W096/09970 ~DI2~;7 PCT/US95/11443 receipt of the PLC transmit flag 675. Once the transmit flag has been acknowledged, as intlic.~tecl by a ready of the acknowledge flag 685, the PLC gets the L~ lliL address start location pointer 680 from the transmit memory area 660ofthe dual port memory 150. The PLC 80 then stores the finger print and variablevalue to the dual port memory 150 beginning at the start address location i-l~.ntified in the transmit address start location pointer 680 identified by the PAM 90. ThePLC 80 then returns from the transmit variable data tasks 850, for example, to receive PAM variable data or, to Lld-lsllliL fi~ther PLC variable data, execute further ladder logic proce.~ing, or exiting the user program.
With respect to the PAM tasks 860, the PAM 90 first reads the PLC
transmit flag 675 to determine whether it is set. If it is in a set state, the PAM 90 icl~ntifies the location to which the PLC 80 is to store the finger print and variable data by placing the start address location in the Ll~lsllliL address start location pointer 680 in the transmit memory area 660 of the dual port memory 150. The PAM 90 then acknowledges the PLC transmit flag 675 by setting the PLC transmit flag acknowledge 685 thus allowing the PLC to send the finger print and variablevalue to the identified location. Once the request has been acknowledged, the PAM
90 reads the finger print and variable value beginnin~ at the location identified in the lld-l~nliL address start location pointer 680. The PAM 90 then clears the PLC
2 o Ll~l~llliL flag and returns to other tasks such as, for example, receiving further PLC
variable data, I,,....~;.n;~ g PAM variable data, or executing further motion profile comm~nrlc wog~ 7o ~2 0 i 2 ~ / PCT/US95111443 ~

The data variables that are co~ ,ic,~ted bclw~ell the PAM 90 and the PLC
80 may have a wide variety of functions. Fxempl~ry data variables that are tr~n.~mitte~l from the PLC 80 to the PAM 90 include:
(a) a system production variable that instructs the PAM 90 to begin 5 rxe~ g a continuous procl~lction cycle upon detection of a start switch depression by the PLC 80 through the I/O int~.rf~e 95;
(b) a system production stop variable, transferred upon the detection of a stop switch depression by the PLC 80 through the I/O interface 95, that instructs the PAM 90 to control the plurality of servo driven p~c~ging stations to stop 0 execution of a continuous production cycle;
~ ) a system step production variable that instructs the PLC 80 to control the plurality of servo driven p~ck~gin~ stations to execute a single production cycle; and (d~ a home variable that instructs the PAM 90 to place one or more of 15 the servo driven p~cl~ging stations at a predetermined reference position.
Exemplary values that may be colllll,ullicated from the PAM 90 to the PLC 80 include:
(a~ a power ON variable, transferred upon detection by the I/O 210 of power supplied to one or more servo driven p~k~gjng mech~ni.cm, that informs the 2 o PLC 80 that power is supplied to the particular servo driven p~c.k~ging mech~ni~m;
(b) a position error variable that informs the PLC 80 that at least one of the servo driven pac~ging mech~ni~m~ has failed to reach a position within an allotted period of time; and S 220 1 2~7 ,; . ~ .
WO~G~ 70~ PCI1US95/11443 ~ ) a torque error variable that informs the PLC 80 that at least one of the servo motors driving the plurality of servo driven p~rl~ing stations requires an excessive amount of torque to execute a predetermin~cl movement.
The foregoing variable data structure and its corresponding implt?ment~tion provide numerous advantages overtraditional inter-processor c~.,.. l~"ications. For example, the present system facilitates high speed communication between the processors in a resource efficient manner.
Further, system development may be made more efficient. In this respect, it should be noted that each version of the PAM software must be re-compiled 10 before it is implement~cl within the PAM while the corresponding PLC software does not require such compil~tion. During system debugging, it may be desirable to limit conllllunications between the PAM 90 and PLC 80 to only several variables. With the present system, both the PAM 90 and PLC 80 may be provided with a complete list of all system variables. During debugging, the PLC software 15 may be used to identify those variables which are to be used during debugging without the necessity of re-compiling the PAM software.
The PAM 90 may be programmed to execute any number of motion profiles to carry out the various p~c~inp process steps implemente~ by the p~c.kslging m~hine illustrated in FIGs. lA and lB. The motion profiles may be stored in the 2 o PAM or may be sent using the communicators described above, from the PLC in an "on the fly" fashion. Exemplary motion profiles are set forth in FIGs. i5-41.
These motion profiles are applicable to filling, for example, a 70x70mm gable top wo g~ o~70 2 2 0 1 2 ~ 7 PCT/US95/11443 ~

carton using proces~in~ stations 45, 50, and 55 such as those set forth in the foregoing identified patent applications.
The use of gearboxes and cams, driven by constant velocity motors, to effect mech~ni.~m motions usually c~ the mech~ni~m motions to co~ t velocity, 5 or sinusoidal acceleration, or "modified sine" acceleration profiles. The present system is not constrained in this fashion. Rather, the present system f~cilit~tes implement~ti~ n of motion profiles that enable, not just the movement of a mech~ni~m from point a to point b in time t, but also profiles with accelerations and velocities that can be tailored to ~ illli7e the collsl~ that, for example, 10 amplifier current and voltage limits or product viscosities impose.
Motion profiles to be rxe~ ed by, for example, the disclosed system using Socapel products, are coded as sequences of positions p; that vary from O to l.
Prior to execution of any particular motion profile the PAM 90:
l) multiplies each PI by a signed (+/-) scale factor equivalent to the m~xi~ angular (1i~t~nre that we want the motor to rotate during any one m~r.hine cycle; and 2) adds to each scaled PI a signed offset magnitude that shifts the initial PI (and all subsequent PI) fol~ d or backward from the motor zero position.
2 o The PAM 90 then assumes:
l) that the sequence of positions to be achieved by the motor during runtime will be spread out over the time of one machine cycle; and ~ 2 0 1 2 ~ ~
wog~ 70 , ~ PcrluS9~/11443 2) the time interval between two adjacent PI is the same as any other two adjacent PI-Then the PAM 90 associates:
po with to Pl Witht1 =to + /~ t P2 with t2 = t1 + ~ t pf with tf = tf-l + /~ t where lo /~ t = m~rhine cycle time/(#pI -1).
An ideal motion profile may be defined in terms of the accelerations (sinusoidal, cosinusoidal, and constant) and positions that the motor is to achieve over the time of a m~rhine cycle. Data points along the ideal position, velocity, and acceleration profiles may then be selected to preserve the shape of the acceleration curve. In practice, this may be between 90 and 360 samples per profile.
To ensure that the PAM 90 and the servomotors 16 are programmed with position profiles that they can execute smoothly, it is presently desirable to create position profiles that are derived from sequences of constant accelerations. To achieve this, the velocity profile that satisfies the initial acceleration and position 2 o profiles is ~ltili7P~ .sllming that each velocity (v;) will be achieved via a constant acceleration, each necessary acceleration (s;) is calcnl~terl The position points p;
are then determined based on the following equation:

wo9~ 970 2~ O ~ PCT/US95/11443 ~

PI = pI 1 + (vI l* ~ t) + (l/2 *sI 1* ~ t)2.

The following motion profiles may be implemented using the foregoing method.

Infeed Conveyor Motion Profile:
The motion profile for the infeed (or lower) conveyor 30 is set forth in FIGs.
15-17, which illustrate the position, velocity, and acceleration profiles respectively.
Sinusoidal accelerations are ~ltili7~-1 instead of more rapidly rising accelerations, to 111 jl~illli7t? jerking ofthe pulleys 35, 40. The time of deceleration is made longer than the acceleration time to reduce the magnitude of deceleration. Higher pulley decelerations may cause the conveyor band to slip fo~ l with respect to the pulley when the band is loaded with cartons thereby causing indexing errors.

WOg~5~70 22~ Pcr/uss5/11443 Upper Conveyor Motor Profile:
The upper collv~yol 25 motion profile may proceed in accordance with the motion profile illustrated in FIGs. 18-20. This profile is basically a 1/3rd, 1/3rd, 1/3rd l,d~ oidal velocity profile. Higher accelerations may outstrip the ability of 5 the servo amplifier to supply current and voltage. During the time of any acceleration (or deceleration) 20% of the time is spent ramping up to constant acceleration and 20% of the time is spent ramping down to zero acceleration. The ramping of accelerations was implement~d to limit jerking of the driven mech~ni~m~

Lifter Motion Profile:
The lifter me~ h~ni~m of station 45 is constructed in accordance with the te~çhing~ of the previously noted 08/315,410 application (Attorney Docket No.
10325US01; Corporate Docket No. TRX-0043) and inr.llltles a bottom lifter and top 15 pre-folder, each driven by a Le~e.;liv~ servomotor. The motion profiles ofthe lifter mech~ni.~m are set forth in FIGs. 21-26.
The motion profile for the bottom lifter is set forth in FIGs. 21-23 and consists of three moves. The first motor move lifts the forks up to the bottoms of the cartons in the lower conveyor band 30. The second move drives the forks up 2 o through the lower conveyor band 30 and into the upper conveyor band 25 so that the bottom sealing areas are of the cartons in the same plane as the jaws of the horn and anvil of the ultrasonic bottom sealer. The third move returns the forks down wo 9~ 970 ~ 2 ~ ~ 2 ~ 7 PCT/US95/11443 ~

to their home position. The third move begins when the jaws of the sealer make contact with the bottom sealing areas of the cartons.
Each move of this profile is basically a l/3rd, l/3rd, l/3rd trapezoidal velocity profile. However, during the time of any acceleration (or deceleration) 5 20% of the time is spent ramping up to constant acceleration and 20% of the time is spent ramping down to zero acceleration. The ramping of accelerations was implement~d to limit jerking of driven mech~ni~m~.
The motion profile for the top pre-folder is set forth in FIGs. 24-26 and consists of four moves. The first motor move drives the prefolder forks down 0 through the upper conveyor band 25 into the lower conveyor band 30 to the level of the carton tops. Since the bottom lift forks arrive at the carton bottoms at the same time, the boKom lift forks and the prefolder forks secure the cartons. The second move draws the prefolder back up through the upper conveyor band 25.
This second move is similar to the second move of the bottom lift but in the opposite ~direction so that the cartons remain secure in the grips of both sets of forks. The third move drives the prefolder down a length sufficient to keep the bottom sealing surfaces of the cartons in the same plane as that of the bottom sealer jaws during jaw closure. Without this downward move of the prefolder, the bottom sealing surfaces of the cartons would slide over the sealer jaws during their closure.
2 o The third move begins when the sealer jaws have made contact with the bottom sealing surfaces of the carton. The fourth move draws the prefolder clear of the carton tops and up to its home position sometime before the upper conveyor band ~ wo ~ g~o 2 2 0 1 2 ~ 7~ PCTIUS95/11443 25 moves. The retraction move begins after the sealer jaws have firmly gripped the carton bottoms.
Each move of the profiles of FIGs. 21-26 is basically a 1/3rd, 1/3rd, 1/3rd tld~e~oidal velocity profile. However, during the time of any acceleration (or deceler~tion) 20% ofthe time is spent r~mping up to col~l~ll acceleration and 20%
of the time is spent ramping down to zero acceleration. The ramping of accelerations was implementto~l to limit jerking of the driven merh~ni~m~.

Bottom Sealer Motion Profile:
1 0 The bottom sealer of station 45 may be consl- ucl~d in accordance with the teachin~.c of the previously noted 08/315,412 application (Attorney Docket No.
10454US01; Corporate Docket No. TRX-0082). The ultrasonic bottom sealer disclosed therein includes a cam merh~ni~m that is driven by a servomotor.
The motion profile for the bottom sealer is set forth in FIGs. 27-29 and includes two moves. The first motor move rotates the cams so that the sealer jaws close. The first motor move begins far enough in advance so that the jaws make contact with the carton bottoms just after the carton bottoms arrive in the plane of the jaws. The second motor move rotates the cams so that the sealer jaws open.
Each move spends 15% of the move time accclc.dlh~g, 70% of the move time at 2 o constant velocity, and 15% of the move time decelerating. The cams are shaped to move the jaws during the constant velocity portion of the move. Thus, the possibility of adding torques required to move the jaws to torques required to accelerate the cams is avoided.

wog~0~370 ~Z'012~i'' PCTIUS95/11443 ~

Eachmove ofthis profile is basically a 15%, 70%, 15% trapezoidal velocity profile. However, during the time of any acceleration (or deceleration) 20% of the acceleration time is spent ramping up to constant acceleration and 20% of the acceleration time is spent ramping down to zero acceleration. The ramping of accelerations was impl~me~te~l to prevent jerking of the driven meçh~ni~m~

Fill Lifter Motion Profile:
The fill lifter of processing station 50 may be constructed in accordance withthete~chin~softheO8/315,410application(AttorneyDocketNo.10325USOl, Corporate DocketNo. TRX-0043) and the 08/315,401 application (Attorney Docket No. 10602USOl, Corporate Docket No. TRX-0044). Each of these applications, as previously noted, is incol~oldled by reference.
The motion profile for the lifter merh~ni.~m is set forth in FIGs. 30-32 and includes four moves. The first motor move drives the fill lift up through the upper conveyor band 25 and the cartons into the fill chambers of the filling stations proximate the fill no771es. The distance moved is sufficient to bring the cartonbottoms within a few mm of the bottom of the fill no7 les. The first move drivesthe lift up as quickly as possible. The accelerations have been ramped and made as small as possible to both il.;ll;lll;~ stress on the bands and couplings and to 2 o minimi7~ ~lem~n~l~ on servo amplifier current.
The second move draws the lift down from the fill nozzle. It begins slightly after filling begins. The second move draws the lift down from the fill nozzle at velocities sufficient to keep the fill nozle close to the level of the liquid as the ~ WO 96/09970 2 2 D ~ 2 .~ 7 PCT/USg~/11443 liquid is dispensed. For hygienic reasons, the lifter me~h~ni~m moves down fast enough to prevent the liquid level from rising to levels that immerse the outside of the no_zles in the liquid. To minimi7e splashing and foam, the lift meGh~nicm moves down slow enough to keep the liquid level close to the bottom of the 5 nozzles. The second move ends when the top sealing areas of the cartons are in the plane of the top sealer jaws.
The third move drives the fill lift up a length sufficient to keep the top sealing surfaces of the cartons in the same plane as that of the top sealer jaws during jaw closure. Without this upward move of the fill lift, the top sealing surfaces of l o the carton may slide under the sealer jaws during their closure. The third move begins when the sealer jaws have made contact with the bottom sealing surfaces of the carton.
The accelerations of the third move have been limited to ~.5 g to assist in preventing carton bulging and food spray. Food sprays are undesirable for hygiene 15 reasons. Bulging cartons are likewise undesirable. First, they are difficult to handle without damage, because the bulging implies an int~rn~l pressure that can abet carton leaks. Further, bulging implies extra oxygen in the carton that can degrade product taste.
The fourth move draws the fill lift down to its home position sometime 2 o before the upper conveyor band 25 in(1exec The retraction move begins after the sealer jaws of the top sealer have released the carton tops.
Each move ofthis profile is basically a 40%, 20%, 40% trapezoidal velocity profile. However, during the time of any acceleration (or deceleration) 20% of the w096/09970 ~20 1 ~ / PCI/US95/11443 time is spent ramping up to constant acceleration and 20% of the time is spent ramping down to zero acceleration. The ramping of accelerations was implemt?ntedto limit jerking of the driven m~r.h~ni~m~.

Fill Pump Motion Profile:
The proces~ing station 50 may include a fill pump that pumps liquid from a storage tank into the cartons. The fill pump includes a piston that reciprocate back and forth to alternately fill and empty a pump chamber. The piston may be driven by a screw mech~ni~m that, in turn, is driven by a servomotor.
The motion profile for the fill pump is illustrated in FIGs. 33-35 and includes two moves. The first move - the fill move -drives the pump piston forward to drive liquid down through the fill nozzle and into the carton. The second move -the recharge move - drives the pump piston backward to draw liquid from the storage tank into the pump chamber.
The aim of the fill move is to get liquid into the carton as fast as possible.
However, pump velocities must be kept below those velocities that cause unacceptable splash and foaming. During the first part of the fill move (the "acceleration" part of the move) the velocities can be, and are, increased dramatically as the liquid depth increases. After some ch~r~rteristic depth is 2 o achieved, the rate of increase in liquid velocities must be slowed to keep splash and foaming to acceptable levels. This defines the second part (the "almost-constant-velocity" part) of the move.

~ Wo 9~a~70 2 2 0 1~2 ~ 7 PCT/US95/11443 During the third part of the fill move, deceleration is done as quickly as possible. The m~nitl-(le of the deceleration is related to the time required to close the outlet valve so that the liquid flow reaches zero at the same time that the outlet valve is closed. If the valve closes too early, an incorrect volume will be delivered to the package. Additionally, if the pump piston cc ntinlles its stroke after the outlet valve closes, the increased fluid ~les~ulcs will force a spray of liquid through the pump housing and diaphragm and out to various parts of the m~r.hine. Such an event con~rolllises the hygiene of the machine. If the valve closes too late, then air will enter the nozzle and the pump chamber which will, again, cause an il~collc~iL
volume to be delivered to the package. The faster the deceleration, the more precise the timing of the valve closing has to be.
During the rcchalge move, accelerations and velocities are limited to prevent gasses from coming out of solution due to pressure reductions. Gas bubbles in the fill pump chamber may cause inaccurate liquid volumes to be delivered to the package. Pump accelerations are kept below those that keep flowaccelerations below 1 g. Pump velocities are kept below those that enable flow velocities of 2 m/s or greater in the recharge pipes.

Top Sealer Motion Profile:
2 o The top sealer of station 50 is, for example, constructed in accordance with the te~çhings of the 08/315,412 application (Attorney Docket No. 10454US01;
Corporate Docket No. TRX-0082). That application, as noted above, is incorporated by reference.

wog~ 970 ~0i2a7 PCTIUS9S/11443 The motion profile for the top sealer is set forth in FIGs. 37-39 and includes two moves which drive the cam. The first move of this profile closes the top sealer jaws. It is an atypical move con~i~ting ofthree polynomial splines. The first spline rotates the cams so that the jaws make contact with the top sealing areas of the 5 cartons ~imlllt~n~ously with their arrival at the jaws. The cams arrive at that point with a very low velocity. The low cam velocity is selected so that the jaw velocities are small enough to give refold merh~ni.~m~, such as those described in U.S.S.N.
08/315,400 (Attorney DocketNo. 10455US01, Co,~oldle DocketNo. TRX-0047), entitled "Al.p~dLus for Sealing the Fin of a Gabled Co~ e~", incol~ldled herein 1 o by reference, time to shape the carton tops for proper folding. At the same time it is desirable to have a velocity greater than zero so that the subsequent acceleration can be instituted without having to overcome static friction.
The second spline ofthe move rotates the cams until the jaws - and thus, the carton tops - are about 5 mm apart. It is desired that this move last lOOms to 15 continue giving time to allow the refold mech~ni~m~ to fold the cartons and, further, to allow excess air to escape from the cartons. It is also desired that the velocity at the end ofthe second spline be as low as possible while still enabling the jaws to finish closing in the next lOOms via the third spline. The low velocity at the end of the second spline (and, thus, at the beginning of the third spline) extends the 2 o time for air esc~lllent into the third spline. The third spline has to decelerate as fast as possible to complete the cam rotation and jaw closing in the allotted l OOms.
The second move opens the top sealer jaws and is the same as the move that opens the bottom sealer jaws. That is, the move spends 15% of the move time wog~ 70 ~ PCr/Uss5/11443 accclcl~ling, 70% ofthe move time at constant velocity, and 15% ofthe move time decçlc~ .g During the time of any acceleration (or decel~r~tiQn) 20% of the timeis spent ramping down to zero acceleration. The ramping of accelerations is implemente~l to reduce jerking of the driven merh~ni~m~.

Bottom Former Lift Motion Profile:
Proces~in~ station 55 inrlll<les a bottom former that forms a fl~tt~n~l seating area from the gabled bottom of each carton. The bottom former may be constructedin accordance with the te~ching~ of the 08/315,403 application (Attorney Docket 0 No. 10599US01; Corporate Docket No. TRX-0064). The bottom former thus includes a cup array that forms the carton bottoms and, further, I .21~ ,~r~. ~ the cartons from the upper conveyor 25 to the outfeed me~ h~ni.cm The cup array is moved by a linear activator (lifter) that is driven by a servomotor.
The motion profile for the lifter is set forth in FIGs. 39-41. The motion profile begins with the cartons already in the cups of the array. At this point the cups can move down ~ll~lcæ the cartons can not move down any further. The first motor move drives the cups down a sufficient (1i~t~nce to allow the ejecting mech~ni~m~ to drive the cartons from the cups and æsure that the top edges of cups cannot "trip" the cartons when they are pushed hol ;~",I;1lly out of the station. The cups have to remain at that level long enough for the pusher of the outfeed mechanism to shove the cartons out and then retract back out of the upward path of the cups.

WO 9~ 70 ~ 2 ~ ~ 2 8 / PCT/USg5/11443 The second move ofthe profile begins as soon as the pushers are clear ofthe upward path of the cups. The second move drives the lift up as fast as the servo ~mplifier can allow. Within the accelerations (or decelerations) of this move 20%
of the time is spent ramping up to constant acceleration and 20% of the time is 5 spent ramping down to zero acceleration. The ramping of accelerations is implemente(l to reduce jerking of the driven mecll~. ,ix" l~ After the lift has finished the move up, it must dwell there long enough to allow the cup vacuum to drive the carton bottoms firmly into the cups.
After the dwell, the third move takes the cup array down as quickly as is 10 nece~ry to reach a level at which the cartons are below any mech~ni~m that would otherwise collide with the cartons and/or lift when the conveyor in(lexes. The ~m~ ost accelerations that enable the avoidance of collisions are desirable, first, to prevent the cups from leaving the cartons behind and, second, to keep the bottom folds of the carton as tight against the cup bottoms as possible.
The fourth move does not have to cope with any abnormal (lem~nfl~ and, thus, is a leisurely drop down to the home position.

Slipping Correction:
For a servo controlled packaging m~hine such as the one disclosed to 2 o perform properly, the m~chine's repeatability of motion should be within design specifications. In most cases, the specification for all motion axes to stop is ~ O.S
mm of the designated stop position. For a well adjusted servo system motor operating freely, this stopping repeatability is not a problem. However, when the ~ wo 9~0~3370 2 2 0 ~ 2 ~ 7 PCr/USs5/11443 motors are linked via belts, chains, and gearboxes to actual physical mech~ni~m~, the b~r~ h and wear of gearboxes and the flex in the belts and chains may cause the final stopping position to be outside the acceptable tolerance limits.
Correction may be accc mpli~hP~ in the servo program through a correcting 5 algol;L~"l, such as the one described below, which detects slippage while the motor is in operation, increases or decreases the motor speed to correct this slippage, and brings the motor to a halt at the correct position. This algol;Ll~", works in conjunction with the normal "motion profile" of the servo motor, and corrects for slippage on-the-fly during the normal operation and thus is able to complete the 0 move in the (le~ign~tecl time. The total m~rhinP cycle time is not altered due to this correction, and the m~rhin.? is able to contim-~lly meet its production requirements.
In addition, the correction algol;Ll~," also monitors the amount of slippage, and if the actual slippage exceeds a preset ms.xi.,.l,,,, allowance, the program may warn the opeldlol of this excessive slippage. The operator, in turn, could check for 15 mechanical damage or problems, and take corrective action.
The operation of the correction algol;Ll.,n is as follows and is understood with reference to FIGs. 42 and 43. Assuming that the distance the mech~ni.~m M
moves is d in time t. The meçh~ni~m M contains a target flag F, which is noticed by the sensors A, B, and C positioned at certain intervals along the distance d. The 2 o width of the flag F is w, which is also the distance between the sensors B and C.
Under normal operation, the mech~ni.cm M is comm~n~le~l to move the distance d in time t, and when it comes to a halt, sensors B and C must be ON in order to ~,u~lee that the merh~ni~m did indeed move the rli~t~nr.e d. However, if sensor 2;2D.1 2~/' WO 96/09970 ' PCT/US95/11443 ~

B and C or both are OFF when the mech~ni~m M completes the move, we can assume that the stop position of M is outside the acceptable limits for the nextmotion to continlle This is where sensor A is used. Sensor A is placed at a distance d, from the start of the move of the m~rh~ni~m M, and the flag F turns it ON briefly during its move after time t,. The time t, when sensor A is turned ON is used to determine whether the motion of me~h~ni~m M is on-track as comm~n-le~l or if there is someslippage. In essence, time t, is compared to a value t,efheld in a register in the servo program, a value that is calculated from theoretical means if the merh~ni~m M were to move as clecigne~l However, due to slippage, t~ could be dirr~le-ll from tref.
If tl>t,~f the mech~ni~m M is lagging during its move tl<t,Cf the mech~ni~m M is leading during its move By co~ ;llg the value of t, to trcf, we can determine the amount and direction of slippage in the mech~ni~m M, and correct for it.
The correction is accomplished in a manner that may be understood with rer~ ce to FIG. 43. Under normal operation, position updates are provided to themotor, and the motor carries out the co"""~"-l However, when the correction algorithm is engaged, an error term is calculated when the sensor A becomes ON.
When sensor A is ON, the time t~ value is noted and coll~a.ed to the trcfvalue. The 2 o difference is then applied to a correction generator algorithm which converts the time difference to position difference, and adds the correction term to the normal input of position updates. This in turn is downloaded to the motor, which carries WO 9G,'~970 2 2 ~ & ~ PCT/US95/11443 out this modified position update in order to reach the lçsi~n~tecl position at the right time.
FIGs. 44 and 45 illustrate a modular-type connection box that may be associated with each a~p~dLus of each procç~in~ station 45, 50, and 55. As 5 illustrated, each a~dLus may have a connection box 1010 that in~hlcles a plurality of signal and power connections. The box 1010 may include a noise shield 1020 disposed between the side 1030 of the box 1010 receiving power and side 1040 of the box 1010 receiving the signal and control lines.
Although the present invention has been described with reference to a o specific embodiment, those of skill in the art will recognize that changes may be made thereto without departing from the scope and spirit of the invention as set forth in the appended claims.

Claims

WE CLAIM AS OUR INVENTION:

1. A packaging machine comprising:
a plurality of servo driven packaging stations, each of the packaging stations executing one or more processes to fill and seal a carton and having one or more servomotors associated therewith;
a plurality of servo amplifiers, each of the servo amplifiers being connected to a respective servomotor for control of the respective servomotor;
a programmable axis manager connected to control the plurality of servo amplifiers;
a programmable logic controller connected to receive and transmit input/output signals associated with the plurality of packaging stations, the programmable axis manager and the programmable logic controller being connected to a common communication bus; and communication means for transferring data variable values between the programmable logic controller and the programmable axis manager over the common bus using predetermined fingerprints assigned to each variable value.

2. A packaging machine as claimed in Claim 1 and further comprising initialization means for placing the programmable axis manager and the programmable logic controller in a predetermined initialized state.

3. A packaging machine as claimed in Claim 2 wherein the initialization means comprises:
exchanging means for exchanging selected CRC values between the programmable axis controller and programmable logic controller, the selected CRC values identifying which variables are to be used in communications between the programmable axis manager and programmable logic controller at runtime; and assigning means for assigning the predetermined fingerprints corresponding to the selected CRC values, the predetermined fingerprints being used to identify each variable in subsequent communications between the programmable logic controller and programmable axis manager at runtime.

4. A packaging machine as claimed in Claim 1 wherein the communication means comprises:
flag means for allowing the programmable logic controller to signal the programmable axis manager that the programmable logic controller has a data variable to send to the programmable axis manager;
identification means for identifying one or more memory locations that are disposed in the programmable axis manager to which the programmable logic controller is to write the predetermined fingerprint and the associated variable value, the identification means being responsive to the flag means; and transfer means for transferring the predetermined fingerprint and the associated variable value from the programmable logic controller to the one or more memory locations identified by the identification means.

5. A packaging machine as claimed in Claim 1 wherein the communication means comprises:
programmable logic controller transmit flag memory disposed in the programmable axis manager and accessible by the programmable logic controller over the common bus for storing a digital signal indicating to the programmable axis manager that the programmable logic controller has a data variable to send to the programmable axis manager;
transmit data memory disposed in the programmable axis manager and accessible by the programmable logic controller over the common bus for storing the fingerprint and associated data variable that is to be sent from the programmable logic controller;
transmit address identification memory disposed in the programmable axis manager and accessible by the programmable logic controller over the common bus for identifying the start address location of the transmit data memory to which the programmable logic controller is to write the predetermined fingerprint and associated data variable that is to be sent by the programmable logic controller; and transmit means for transmitting the predetermined fingerprint and the associated data variable to the transmit data memory address locations identified in the transmit address memory.

6. A packaging machine as claimed in Claim 5 wherein the receive data memory and address memory are located in dual port memory disposed in the programmable axis manager.

7. A packaging machine as claimed in Claim 6 wherein the programmable logic controller transmit flag memory is located within the dual port memory.

8. A packaging machine as claimed in Claim 1 wherein the communication means comprises:
programmable axis manager flag means for allowing the programmable axis manager to signal the programmable logic controller that the programmable axis manager controller has a data variable to send to the programmable logic controller;

identification means for identifying one or more memory locations that are disposed in the programmable axis manager from which the programmable logic controller is to read the predetermined fingerprint and the associated variable value, the identification means being responsive to the flag means; and read means for reading the predetermined fingerprint and the associated variable value from the one or more memory locations identified by the identification means.

9. A packaging machine as claimed in Claim 1 wherein the communication means comprises:
programmable axis manager transmit flag memory disposed in the programmable axis manager and accessible by the programmable logic controller over the common bus for storing a digital signal indicating to the programmable logic controller that the programmable axis manager has a data variable to send to the programmable logic controller;
receive data memory disposed in the programmable axis manager and accessible by the programmable logic controller over the common bus for storing the fingerprint and associated data variable that is to be read by the programmable logic controller;
receive address identification memory disposed in the programmable axis manager and accessible by the programmable logic controller over the common bus for identifying the start address location of the transmit data memory from which the programmable logic controller is to read the predetermined fingerprint and associated data variable that is to be sent to the programmable logic controller; and read means for allowing the programmable logic controller to read the predetermined fingerprint and the associated data variable from the receive data memory address locations identified in the receive address memory.

10. A packaging machine as claimed in Claim 9 wherein the transmit data memory and address memory are located in dual port memory disposed in the programmable axis manager.

11. A packaging machine as claimed in Claim 10 wherein the programmable axis manager transmit flag memory is located within the dual port memory.

12. A packaging machine as claimed in Claim 1 wherein the plurality of packaging stations comprise a carton lifter mechanism.

13. A packaging machine as claimed in Claim 12 wherein the communication means transfers a lifter mechanism home variable from the programmable logic controller to the programmable axis manager that instructs the programmable axis manager to place the lifter mechanism at a predetermined reference position.

14. A packaging machine as claimed in Claim 12 wherein the servo amplifier that is connected to control the lifter mechanism is further connected to sense that power is supplied to the lifter mechanism.

15. A packaging machine as claimed in Claim 12 wherein the communication means transfers a lifter mechanism power on variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that power is supplied to the lifter mechanism.

16. A packaging machine as claimed in Claim 12 wherein the communication means transfers a lifter mechanism position error variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that the lifter mechanism has failed to reach a position within an allotted predetermined period of time.

17. A packaging machine as claimed in Claim 12 wherein the communication means transfers a lifter mechanism torque error variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that the servomotor driving the lifter mechanism requires an excessive amount of torque to execute a predetermined movement.

18. A packaging machine as claimed in Claim 1 wherein the plurality of packaging stations comprise a carton pre-folder mechanism.

19. A packaging machine as claimed in Claim 18 wherein the communication means transfers a pre-folder mechanism home variable from the programmable logic controller to the programmable axis manager that instructs the programmable axis manager to place the pre-folder mechanism at a predetermined reference position.

20. A packaging machine as claimed in Claim 18 wherein the servo amplifier that is connected to control the pre-folder mechanism is further connected to sense that power is supplied to the pre-folder mechanism.

21. A packaging machine as claimed in Claim 18 wherein the communication means transfers a pre-folder mechanism power on variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that power is supplied to the pre-folder mechanism.

22. A packaging machine as claimed in Claim 18 wherein the communication means transfers a pre-folder mechanism position error variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that the pre-folder mechanism has failed to reach a position within an allotted predetermined period of time.

23. A packaging machine as claimed in Claim 18 wherein the communication means transfers a pre-folder mechanism torque error variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that the servomotor driving the pre-folder mechanism requires an excessive amount of torque to execute a predetermined movement.

24. A packaging machine as claimed in Claim 1 wherein the communication means transfers a system production variable from the programmable logic controller to the programmable axis manager that instructs the programmable axis manager to control the plurality of servo driven packaging stations to execute a continuous production cycle.

25. A packaging machine as claimed in Claim 1 wherein the communication means transfers a system production stop variable from the programmable logic controller to the programmable axis manager that instructs the programmable axis manager to control the plurality of servo driven packaging stations to stop execution of a continuous production cycle.

26. A packaging machine as claimed in Claim 1 wherein the communication means transfers a system step production variable from the programmable logic controller to the programmable axis manager that instructs the programmable logic controller to control the plurality of servo driven packaging stations to execute a single production cycle.

27. A packaging machine as claimed in Claim 1 wherein the communication means transfers a home variable from the programmable logic controller to the programmable axis manager that instructs the programmable axis manager to place one or more of the servo driven packaging stations at a predetermined reference position.

28. A packaging machine as claimed in Claim 1 wherein the communication means transfers at least one power on variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that power is supplied to at least one servo driven packaging mechanism.

29. A packaging machine as claimed in Claim 1 wherein the communication means transfers a position error variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that at least one of the servo driven packaging mechanisms has failed to reach a position within an allotted period of time.

30. A packaging machine as claimed in Claim 1 wherein the communication means transfers a torque error variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that at least one of the servomotors driving the plurality of servo driven packaging stations requires an excessive amount of torque to execute a predetermined movement.

31. A packaging machine comprising:
a plurality of servo driven packaging stations, each of the packaging stations executing one or more processes to fill and seal a carton and having one or more servomotors associated therewith;
a plurality of servo amplifiers, each of the servo amplifiers being connected to a respective servomotor for control of the respective servomotor;
a programmable axis manager connected to control the plurality of servo amplifiers, the programmable axis manager including PAM program memory and dual port memory;

a programmable logic controller connected to receive and transmit input/output signals associated with the plurality of packaging stations, the programmable logic controller including programmable logic controller program memory, the programmable axis manager and the programmable logic controller being connected to a common communication bus, the programmable logic controller accessing the dual port memory over the common communication bus; and communication means for transferring data variable values between the programmable logic controller and the programmable axis manager over the common bus using predetermined fingerprints assigned to each variable value, the communication means comprising the dual port memory, code in the programmable logic controller program memory, and code in the programmable axis manager program memory.

32. A packaging machine as claimed in Claim 31 and further comprising initialization means for placing the programmable axis manager and the programmable logic controller in a predetermined initialized state.

33. A packaging machine as claimed in Claim 32 wherein the initialization means comprises:

exchanging means for exchanging selected CRC values between the programmable axis manager and programmable logic controller, the selected CRC values identifying which variables are to be used in communications between the programmable axis manager and programmable logic controller at runtime, and assigning means for assigning the predetermined fingerprints corresponding to the selected CRC values, the predetermined fingerprints being used to identify each variable in subsequent communications between the programmable logic controller and programmable axis manager at runtime.

34. A packaging machine as claimed in Claim 31 wherein the communication means comprises:
transmit flag memory disposed in the dual port memory for storing a digital signal indicating to the programmable axis manager that the programmable logic controller has a data variable to send to the programmable axis manager;
receive data memory disposed in the dual port memory for storing the fingerprint and associated data variable that is to be sent from the programmable logic controller, address memory disposed in the dual port memory for identifying the start address location of the receive data memory to which the programmable logic controller is to write the predetermined fingerprint and associated data variable that is to be sent by the programmable logic controller; and transfer means for transferring the predetermined fingerprint and the associated data variable to the receive data memory address locations identified in the address memory.

35. A packaging machine as claimed in Claim 31 wherein the communication means comprises:
programmable axis manager transmit flag memory disposed in the dual port memory for storing a digital signal indicating to the programmable logic controller that the programmable axis manager has a data variable to send to the programmable logic controller;
transmit data memory disposed in the dual port memory for storing the fingerprint and associated data variable that is to be sent to the programmable logic controller;
address memory disposed in the dual port memory for identifying the start address location of the transmit data memory from which the programmable logic controller is to read the predetermined fingerprint and associated data variable that is to be sent to the programmable logic controller; and transfer means for transferring the predetermined fingerprint and the associated data variable from the receive data memory address locations identified in the address memory to the programmable logic controller.

36. A packaging machine as claimed in Claim 31 wherein the communication means transfers a system production variable from the programmable logic controller to the programmable axis manager that instructs the programmable axis manager to control the plurality of servo driven packaging stations to execute a continuous production cycle.

37. A packaging machine as claimed in Claim 31 wherein the communication means transfers a system production stop variable from the programmable logic controller to the programmable axis manager that instructs the programmable axis manager to control the plurality of servo driven packaging stations to stop execution of a continuous production cycle.

38. A packaging machine as claimed in Claim 31 wherein the communication means transfers a system step production variable from the programmable logic controller to the programmable axis manager that instructs the programmable logic controller to control the plurality of servo driven packaging stations to execute a single production cycle.

39. A packaging machine as claimed in Claim 31 wherein the communication means transfers a home variable from the programmable logic controller to the programmable axis manager that instructs the programmable axis manager to place one or more of the servo driven packaging stations at a predetermined reference position.

40. A packaging machine as claimed in Claim 31 wherein the communication means transfers at least one power on variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that power is supplied to at least one servo driven packaging mechanism.

41. A packaging machine as claimed in Claim 31 wherein the communication means transfers a position error variable from the programmable axis manager to the programmable logic controller that informs the programmable logic controller that at least one of the servo driven packaging mechanisms has failed to reach a position within an allotted period of time.

42. A packaging machine as claimed in Claim 31 wherein the communication means transfers a torque error variable from the programmable axis controller to the programmable logic controller that informs the programmable logic controller that at least one of the servomotors driving the plurality of servo driven packaging stations requires an excessive amount of torque to execute a predetermined movement.