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MAN414 - Quin Systems Ltd

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1. Copyright 1995 Quin Systems Limited Page 11 PTS User s Guide Revision 2 3 3 7 Setting Up a Reference Input To select input 1 as a reference input you need to define a reference input Type in one of the following 1 This command defines the reference on input 1 on a falling edge i e the signal switching from high voltage to zero volts 1 This command defines the reference on input 1 on a rising edge i e the signal switching from zero to high voltage Page 12 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 3 8 Saving Parameters Once the reference line has been defined it should be saved in non volatile memory to save repeating the exercise next time the PTS is switched on There is only one save command and it saves ALL PTS parameters at their current values For this reason it must be used with care Saving parameters is only possible in privileged mode Save Parameters This command saves all PTS parameters to non volatile memory When the parameters are saved a number will be displayed on the screen This number is the checksum value calculated by the PTS on the stored parameters The PTS uses this value when it is next switched on to check the non volatile memory If the memory is not working properly then next time the PTS is switched on the error message F will be displayed on the screen Otherwise the number can be ignored
2. Page 62 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 5 2 Maps If the ratio is 1 1 in terms of encoder counts then the axes will be of equal length and the angle of the graph defining the relative positions will be 45 The graphs of master slave positional relationships are known as maps and these can be stored in the PTS A set of maps are often used to define a transmission involving a number of motions A great benefit of this type of transmission is to be able to store different sets of maps in order to provide different transmission systems for a particular machine Copyright 1995 Quin Systems Limited Page 63 PTS User s Guide Revision 2 5 3 Setting Up the Software Gearbox The procedure for creating a simple Software Gearbox transmission between two motions is outlined here Set up the bounds on both master and slave channels Enter the required map for the slave channel Link the slave axis to the master axis Execute the map on the slave axis The procedure will be described in more detail by working through a simple example This example implements a simple 2 1 ratio between two encoders each producing 4000 counts per revolution and it uses channel 1 as the master axis 5 3 1 Setting the Bounds The bounds must be set on both the master and slave channels before commencing with linking the channels together Example System Command Comments 1 gt SB4000 Set the
3. 0 2 x 0 25 7241 3919 2 x 0 25 9461 7241 2 x 0 25 10240 9461 2 x 0 25 10240 9461 2 x 0 25 9461 7241 2 x 0 25 7241 3919 2 x 0 25 3919 0 2 x 0 25 These are the values to be entered into the profile table on the PTS using the enter profile command described later Note that to define the profile as in the above table as changes in position at each time step the system nust be put into the relative position format as mentioned earlier This is done with the set display options word command Please refer to the PTS Reference Manual for more details The alternative absolute position format measures each step end point from the original start and can be more convenient when a spreadsheet is used to create the file of values Copyright 1995 Quin Systems Limited Page 49 PTS User s Guide Revision 2 3 11 2 Profile Velocity The time interval for each time step is set by the profile velocity command nn Set profile velocity When a profile is executed the system steps through the profile table at a rate determined by the value of The shortest time step between profile entries is 1 256 second about 4 ms For the multi axis systems the rate is entered as ticks per second 1 to 256 The basic single axis servos expect a power of 2 exponent 0 to 8 thus PV5 2 5 32 ticks second The value can be changed to shorten or lengthen the time taken for the profile This
4. 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 12 4 Correcting the Reference Error The measured reference error can be used to alter the measured encoder position thus aligning the encoder to each reference signal from the datum The various options for the action taken when the reference input signal is detected are controlled using the IRW reference word command RW 1 Switches ON auto correction RW 0 Switches OFF auto correction NOTE The command is different from those previously described Although looks like a decimal number as shown in the previous example it is in fact entered as a BINARY number Thus 1 is the same as 00000001 and 0 is the same as 00000000 Each BIT in the binary word represents a different function The Auto correction function just described is enabled and disabled by BIT 0 of Copyright 1995 Quin Systems Limited Page 55 PTS User s Guide Revision 2 3 12 5 Limiting the Correction The auto correction can be controlled in many ways For example a useful option is to be able to correct for the proximity detector or registration mark on a printed bag only within a small range of encoder counts from the boundary between cycles This offers the following benefits Filtering out extraneous signals outside that range such as other marks on printed film around the registration mark Only comparing the boundary with the nearest registration mark For example if
5. 1995 Quin Systems Limited Page 69 PTS User s Guide Revision 2 5 5 1 Stopping or Disengaging the Map To disengage the map and stop the synchronisation all that is needed is to switch to the slave channel and execute the stop command Example System Command Comments 1 gt CH2 Switch to the slave axis channel 2 2X ST Stop synchronisation 2 gt Motor2 stopped not synchronised The map can be re engaged at any time by executing the map with the execute map command used previously again making sure that the master axis has come to a rest unless the Software Clutch is in operation Example System Command Comments 2 gt CH 1 Switch to the master axis channel 1 1V ST Stop master motor if still moving 1 gt Motor1 stopped CH2 Switch to the slave axis channel 2 2 gt XM 1 Execute map 1 2M Channel 2 aligning to channel 1 2X Channel 2 in mapped state 5 5 2 Changing Maps A powerful feature of the PTS is its ability to run different maps to implement different transmissions between motions Before a new map is executed it is vital to check if the values of the bounds required for the new map are different If the bounds required are different then the slave must be unlinked from the master axis and the new bounds values entered before re linking the slave back to the master Unlinking a slave from a master is achieved with the command Page 70 Copyright 1995 Quin Systems Limited Revision 2 Example Sys
6. Quin Systems Limited Programmable Transmission System User s Guide Revision 2 December 1995 MAN414 Copyright Notice Copyright 1995 Quin Systems Limited All rights reserved Reproduction of this document in part or whole by any means without the prior written consent of Quin Systems Limited is strictly prohibited Software Version This manual reflects the following software versions e Host software version 3 1 or higher e Servo Module device driver version 18 or higher Servo Module firmware version 27 8 or higher MiniPTS firmware version 1 7 or higher Important Notice Quin Systems reserves the right to make changes without notice in the products described in this document in order to improve design or performance and for further product development Examples given are for illustration only and no responsibility is assumed for their suitability in particular applications Although every attempt has been made to ensure the accuracy of the information in this document Quin Systems assumes no liability for inadvertent errors Suggestions for improvements in either the products or the documentation are welcome Revision 2 Contents 1 Introduction 2 General Description Section A Single Axis Control 3 1 3 2 3 3 3 4 3 5 3 6 3 7 3 8 3 9 3 10 3 11 3 12 Scope of this section Description of PTS 1 Setting Up the PTS 1 Motion Error Handling Differences Between Linear
7. SI lt CR gt Type a carriage return to end sequence gt Ready The sequence can now be run with the single execute sequence command 1 System Command Comments gt XS1 Execute sequence 1 M Index 1 W Wait M Index 2 Ww Wait M Index 3 W Wait M Index 4 Ww Wait gt End of sequence Copyright 1995 Quin Systems Limited Page 29 PTS User s Guide Revision 2 3 8 1 Multi line Sequences More than one command line may be entered as a stored sequence Example System Command Comments gt ES2 Enter sequence 2 S2 SA30000 SV5000 Set acceleration and velocity 52 MA15000 Move to position 15000 counts 2 MR1000 MR 1000 RP2 Oscillate 3 times 52 WT256 DP Wait 1 second then display position S2 MAO Return to zero S2 lt CR gt End sequence gt Ready As shown in this example it does not matter whether commands are all on one line or on separate lines unless there is a repeat loop in the sequence The repeat command only applies to the one command line it terminates In this way a number of different loops can exist in one sequence Sequence 2 can now be run with the 2 command System Command Comments 2 Execute sequence 2 Moving to position 15000 Six oscillations Waiting for one second Display current position Return to zero End of sequence VLLL Page 30 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 8 2 Nesting Sequences You can combine indepen
8. The set output and clear output commands allow individual outputs on the PTS to be set or cleared Example n Set Output n high 24v The line number n is in the range 1 7 n Clear Output n low Ov These commands can be added to the initialise function to signal to an external PLC when the initialisation has completed Example DI2 1 IN 1 When input 2 goes low set output 1 high initialise forwards then clear output 1 PLC PTS Output A ZZ gt Input 2 Time SO1 Input A e Output 1 lt IN CO1 z Output 1 lt This acknowledgement back to the PLC could also be added to the indexing sequence to report that the motion requested is complete Example DI3 XS1 So 1 WT3 co 1 Input 3 going low will trigger sequence 1 then set output 1 wait for 12 ms then clear output again PLC PTS Output B ae gt Input 3 Time xs1 Vv SO1 Output 1 aI WT3 CO1 Output 1 lt 12 ms pulse This sequence also shows that a pulse can be sent to a PLC by using the wait for time command so that the output is cleared ready for the next sequence yet stays high long enough for a PLC to see it Page 36 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide Output 1 could in fact be used in two different sequences acting as a ready line back to the PLC You would not though be able to share input lines between different sequences in the same wa
9. in and should be followed by a carriage return lt CR gt If the commands are not entered correctly then it is likely that the E error will be returned followed by the prompt Just enter the command again Just as in tuning the system system definitions can only be changed when the PTS is set to privileged mode Type in the following lt CR gt You will then be prompted to provide the password If you have not yet entered your own password then the default is just a carriage return Enter Password lt CR gt O K Acknowledgement if the password is correct 3 3 2 Setting the Clock Although not essential it is useful to set the internal clock in the PTS to the current time The command is as follows hh mm ss Set time to hh hours mm minutes and ss seconds The setting can be checked by displaying the setting of the clock in the PTS Displays current time in hh mm ss format Copyright 1995 Quin Systems Limited Page 7 PTS User s Guide Revision 2 3 3 3 Setting Up PTS Limit Switches Before commencing with any motion control it is important to set up position limit switches at the extremes of the motion This is of course in addition to external hardwired switches outside the limit switches just mentioned which should be wired directly to the drive power circuits cutting all power to the motors should they be activated If the resultant motion of the mechanical system is rotary
10. MAP SIZE LIMIT OF STANDARD SRV 1 BASED PTS The maximum length of the MASTER axis in any MAP is limited to 14000 counts This should be borne in mind when entering a large MAP In most cases this does not create a problem but if a very high resolution MASTER encoder is needed over a LONG cycle then a MASTER MAP DIVIDE function can be used to reduce the size of the map table This is described in the PTS Reference Manual However entering every point for a large map is extremely tedious for just a simple ratio Fortunately the PTS can linearly interpolate between entered positions reducing the number of positions that need to be entered manually In the case of a simple ratio as the map graph is a straight line anyway only the first and last points need to be entered The distance between entered points in master axis encoder counts is set by the map step command nn Set the MAP STEP to nn counts Using the master bounds setting of 4000 counts from the first example enter a map step of 4000 counts The map step always relates to the master axis but applies to the map executed on the slave axis A map is entered at the step value of the current axis which would usually therefore be the slave to be used However the step value can be defined inside the map see the Reference Manual Example System Command Comments 2 gt MS 4000 Set the map step to 4000 counts 2 gt To enter the map it is now only nece
11. Page 66 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 5 3 4 Execute the Map The last step in synchronising a slave channel to a master is executing the map This is achieved by the execute map command n where n is the number of the particular map to be executed The execute map command must be entered on the slave channel ensuring that the master axis is stopped Example System Command Comments 2 gt XM 1 From the slave channel execute map 1 2X Channel 2 goes to the mapped state If the encoder positions on the master and slave channels are not lined up prior to executing the map then the slave motor moves until the positions align according to the map defined and then goes into the map state NOTE Other options are available to cater for the MASTER axis moving prior to executing a map This facility is called the SOFTWARE CLUTCH and is controlled by the or MAP WORD function described later Example System Command Comments 2 gt XM 1 From the slave channel execute map 1 2X The slave motor aligns its position to the master 2X The slave goes to the mapped state All the time channel 2 is mapped to a master channel the X prompt is displayed indicating that channel 2 is cross linked to a master axis and is in the mapped state Most commands can still be entered while executing a mapping except for other move commands For example display position read inputs and
12. initialising When initialisation is complete the gt prompt is displayed CAUTION The default settings for the velocity and acceleration can easily be changed although it is a good idea to maintain a low velocity during initialisation in case the reference detector is not triggered In an application where the motion is rotary the motor would just continue to run in the direction given in the command In a linear application it is vital that limit switches are set up prior to initialisation as the motor could run into the end stops if the reference point is not detected Page 14 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 4 Motion Before dealing with motion it is important to understand how to stop 3 4 1 Stopping The motion can be stopped at any time There are three main methods of stopping Stop This command causes the motor to decelerate at the preset ramp rate until it comes to a halt ST Velocity Time Abort This command performs an emergency stop using the reverse torque of the motor as a brake AB Velocity Time Motor off This command puts the PTS directly into the motor off state where the motor position is no longer controlled This allows the motor to be stopped by an external brake if required MO Velocity ie Motor freewheels or Fe externally Time The stop commands can be typed in at any time during initialisation or motio
13. Application If an existing appliction is to be worked on first select the appropriate application directory The file type in the filename box is automatically set to PTS and therefore any PTS file in this directory will be displayed Choose the filename with the latest version number It may be necessary to use the scroll bar to search downwards Having selected the latest file it should then be saved with the next version number This will make sure that any modifications are made to a separate file and will allow modifications to be backtracked if required This is done as follows Select FILE SAVE AS The SAVE AS dialogue box will appear If the latest program file name was PRINT_04 PTS for example specify PRINT_05 PTS in the filename box The directory will already be correct 7 6 Off line Program Editing In opening a text file within PTS Toolkit a PTS Note text editor window will be created This is similar to the windows Notepad editor and allows the PTS program to be edited off line Refer to the on line help file for a detailed description of how to use PTS Note The program should be saved to disk periodically This can be done using the FILE SAVE commands in the pulldown menu or by clicking on the floppy disk icon This will save the program with the pathname shown at the top of the PTSnote text editor window It will overwrite the existing file It is often useful to view existing application programs while creating
14. BT4 MW00010000 VM1 New Map Calculation ES10 MSG 3 MST gt MST 1 MST gt XS201 M00 0 Revision 2 Position loop velocity feedforward To correspond with zero position Speed mapping For alignments Rounded down referencing is required For alignments For jogging Prevents TO errors when MB changed Set point High limit Low limit Positive direction clockwise For alignments Position loop proportional gain Position loop velocity feedback Position loop velocity feedforward Speed mapping For alignments Bound value depends on registration length For alignments For jogging Positive direction anti clockwise Nominal bound value Speed averaging to smooth encoder jitter Always speed mapped Runs as a virtual master slave Calculating print drum profile Undefine to allow preset value to be given Preset to 1 prior to running mapgen Continue map generation Master start position M01 LEN 2 5 ECM 100 Half print distance 5mm window M02 REG ECM 200 M04 REG ECM 100 M03 M04 M01 M05 0 S00 0 Half registration distance Registration distance Start of print 5mm window End of map definition Slave start position S01 LEN 2 5 PCM 100 Half print distance 5mm window S02 5 188 S03 10376 S01 S04 10376 F00 1 F01 3 F02 3 F03 1 NUM 1 CH2 ST MTR 1 Start of pri
15. Quin Systems Limited Page 75 PTS User s Guide Revision 2 Vs The Programming Environment Although an application can be developed interactively using a dumb terminal connected to the serial port of the Quin Controller it is better practice to use a PC instead of a dumb terminal This PC should be running the windows based PTS Toolkit software supplied by Quin and which will provide a flexible working environment offering the following features 1 The application program is saved as a master copy on the PC 2 A history of program versions can be maintained 3 Sections of existing programs can be copied into new programs 4 Programs program sections and individual command lines can be commented 5 A terminal window and a text editor window can be open at the same time allowing text to be cut and pasted backwards as well as forwards 6 Motors can be tuned interactively and their performance monitored graphically using a built in scope facility A full description of how to use PTS Toolkit is given as a help file within PTS Toolkit itself and in the handbook supplied with the product In order to master the windows based programming environment for the PTS a knowledge of using windows applications is also required This can be gained from manuals supplied with the PC Page 76 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 7 1 The Program Structure The structure of an application program for a
16. S1 CO1 IN SO1 Sequence 1 S1 to initialise S2 MR3300 3 RP2 Sequence 2 S2 to do one 90 index then wait for filling operation to complete 3 and repeat another 2 times total 270 S3 XS2 MA13200 WI 3 RP Execute above sequence then do last 90 index to complete one revolution wait for next filling operation to complete and repeat indefinitely S4 XS1 XS3 Sequence to run start and control entire machine cycle DI2 XS4 Define Input line 2 to run entire machine cycle DI3 Undefine previous definition of input 3 which will now be used to sense completion of the filling operation NOTES 1 The above sequence now uses WI3 instead of WT128 as used previously This is preferable as the loop is now properly closed on the filling operation and the cycle can recommence as soon as the filling is complete If the filling cannot complete for any reason then the machine cycle will be suspended until it can proceed 2 The precaution has been taken to include at least one absolute move in the sequence to ensure that there are no accumulated errors which may arise if only relative moves are used 3 Input 3 can be used from more than one sequence Page 42 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 9 8 Imitating a Cam Switch Applications like the indexing starwheel need the motion to interact with other elements in the machine For example the filling head val
17. SA30000 SV 5000 S2 MA15000 S2 MR1000 MR 1000 RP2 S2 WT256 DP S2 MAO gt Ready 3 List sequence 3 S3 XS1 XS2 RP gt Page 32 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 8 4 Saving Sequences The sequences you have now entered can be saved in non volatile memory with the same save parameters command used previously to save the reference input line definitions System Command Comments gt PM Enter privileged mode Password lt CR gt Press return default O K Acknowledgement gt SP Save parameters 96 Checksum value will differ after any setup change gt Ready All three sequences have now been saved but so also has every other parameter entered such as and Sv Next time the PTS is switched on the sequences will be there already and can be run directly with the xs 1 XS 2 or XS 3 commands Copyright 1995 Quin Systems Limited Page 33 PTS User s Guide Revision 2 3 9 Linking the PTS to External Switches or a PLC In all the previous examples the PTS needs to be initialised before running a motion sequence This was accomplished previously by calling the indexing sequence after running the initialisation sequence It may be desirable instead to control the PTS externally either with switches or a PLC which could be supervising the whole machine The initialise function and the indexing function can now be allocated to individual input lines Assum
18. You can remain in privileged mode for the entire session but it is a good idea to return to normal mode to prevent the possibility of overwriting a previous setup Normal Mode This command returns the PTS to the normal protected state Once in normal mode most setup commands will be ignored and return the error message R which means that you are trying to use a restricted command Copyright 1995 Quin Systems Limited Page 13 PTS User s Guide Revision 2 3 3 9 Initialisation You can now initialise the position to the proximity switch Lug belt IN Initialises the motor to the zero position in the positive direction clockwise Proximity switch Lug belt IN Initialises the motor to the zero position in the negative direction anticlockwise Si Proximity switch The motor now accelerates up to the set speed of 1024 counts second default at an 2 acceleration of 1024 counts second default until the proximity switch is detected At that point the position is immediately set to zero and the motor decelerates at 2 1024 counts second until it stops 2 The velocity of 1024 counts second and the acceleration of 1024 counts second can be changed by using the and commands respectively These will be described later The motor now moves back to where the zero position was detected During initialisation the prompt changes to P which indicates that the PTS is
19. a new application More than one PTSnote window can be opened at any one time These windows can be split or tiled on the screen and text can be copied from one window to another Refer to the on line help file for full details Page 80 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 7 7 On line Programming Procedure PTSmotion allows a terminal window to be opened alongside one or more PTSnote text editor windows This provides an RS232 connection from a serial port on the PC to the programming port PORT A on a PTS Refer to the PTS Toolkit User Manual for information on a suitable serial lead TOOLS TERMINAL The COM ports can be selected from the OPTIONS menu With a terminal window open it is possible to communicate directly to a PTS and to make changes to parameters and to any existing program on the PTS While this is very convenient and allows parameter values to be changed immediately on the PTS for testing and experimentation it is important that any on line changes which need to be kept should be made to the program text file in the PTSnote window This will maintain a master copy of the program on the PC It is normal programming practice to make more significant changes in the PTSnote window and to then copy them into the terminal window This then ensures that the master copy is maintained and that the program in the PTS is kept up to date with it Refer to the PTS Toolkit help file for informati
20. bounds 24 map step 65 position error 21 profile velocity 50 reference correction limit 56 timeout 22 velocity 18 window 20 set bounds in mapping 64 set output 36 set position control mode 9 setting the clock i simultaneous motion 60 slave axis 61 SO 36 software cam 47 software clutch 67 70 software gearbox 61 SP 13 33 37 68 speed control 45 SR 56 ST 15 25 45 70 72 stop 15 70 72 stop on external signal 37 stored sequence 29 string of commands 25 SV 14 18 46 50 SW 20 27 switch channels 59 S wrap rollers 74 T T error message 22 tension control 73 89 time between profile points 50 time set 7 timeout 22 TO 22 trapezoidal move 16 triangular move 16 trigger variables 88 TS 7 Page 101 PTS User s Guide U U error message UL unlink using inputs in sequences V VC velocity velocity control velocity profile vibration virtual channel W wait for input wait for time wear WI worked examples WT X X prompt XM XS Z zero position Page 102 37 70 70 41 45 18 45 47 47 88 41 28 47 41 86 28 67 67 70 29 30 31 11 14 53 Revision 2 Copyright 1995 Quin Systems Limited
21. bounds on channel 1 to one revolution 1 gt CH2 Change to channel 2 2 gt SB8000 Set the bounds on channel 2 to two revolutions 2 gt As the example is only a simple linear ratio you do not necessarily need to define the cycle length of the master over a complete revolution since the ratio is constant For example a roller or conveyor belt which has a uniform surface can be started and stopped in any position and therefore you only need to define the ratio between master and slave axes The minimum requirement is to define the ratio of the master bound to the slave bound Example System Command Comments 1 gt SB100 Set the bounds on channel 1 to 1 40 of a revolution 1 gt CH2 Change to channel 2 2 gt SB200 Set the bounds on channel 2 to 1 20 of a revolution 2 gt If you decide to only define the cycle over part of a revolution it must be remembered that absolute position only applies within the range of the bounds defined So if you need to know the position of channel 1 or 2 to the nearest revolution then you must set the bounds to a complete revolution Page 64 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 5 3 2 Entering a Map It is possible to enter a slave encoder position for every master encoder position thus forming the line of the graph in a map This makes the synchronisation very accurate and allows very fine control of the profile of the map graph as will be described later NOTE
22. code for printing 1 constant velocity Function code for limp 3 sine squared Function code for limp 3 sine squared Function code for printing 1 constant velocity Master position start of map 0 Master position end of print Master position at half cycle point Master position start of print Master position end of cycle SB Master position end of map definition 0 Set to force map recalculation if map parameter is changed Map number Slave position Start of map 0 Slave position end of print Slave position at half cycle point Slave position start of print Slave position end of cycle SB Copyright 1995 Quin Systems Limited Revision 2 Sequence Definitions PTS User s Guide 10 New Map Calculation 91 Channel 1 error sequence 92 Channel 2 error sequence 93 Channel 3 error sequence 99 Tension error sequence 100 Start Machine 102 Start machine Right to Left 104 Start machine Left to Right 110 Stop Machine 111 Stop machine if not printing 112 Stop machine if printing 113 Check if master slowed down 150 Inch start stop machine 160 Inch start machine 162 Inch start Right to Left 164 Inch start Left to Right 170 Inch stop machine 200 Initialisation sequence 201 Continuation of initialisation after map generation 255 Autostart sequence PM Prepare for download ED For edit mode Global parameters AS255 Ru
23. command as described in Section A can be used to ascertain the free memory available at any particular time Page 68 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 5 5 Mapping Having linked a slave channel to a master and then executed a map the two axes are now synchronised All that is necessary is to switch to the master channel and execute any commands The slave channel follows the master according to the map being executed on the slave Example System Command Comments 2 gt CH1 Switch to the master axis channel 1 1 gt SV5000 VC Set the master velocity to 5000 counts second and run at that velocity 1V Motor2 should now follow in the same direction at twice the velocity about 10000 counts per second This can be observed by switching back to channel 2 and measuring the velocity with the display measured velocity command Example System Command Comments 1V CH2 Switch back to the slave channel 2 2X DV Display measured velocity 10240 Measured slave velocity 2X The motion can be stopped at any time in the normal way by switching back to the master channel and stopping the master motor As the master motor stops the slave remains synchronised to it Example System Command Comments 2X CH1 Switch to the master axis channel 1 1V ST Stop the master motor 1S Stopping 1 gt Stopped 1 gt CH2 Switch to the slave axis channel 2 2X The slave is still mapped to the master Copyright
24. cycle time is more adjustable than using a profile alone In this application the virtual channel is used to avoid a particular problem Page 88 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide The figure shows the machine layout The print drum needs to be synchronised to the motion of the web This is monitored by the encoder which is driven by the web Instead of the print drum being position mapped directly to the encoder it is position mapped to a virtual channel which itself is speed mapped to the encoder This is done for the following reason During printing the print characters on the print drum must contact the paper If the web is disturbed in any way during printing then the encoder will be affected If the print drum is directly mapped to the encoder this would feed back to the motion of print drum This would provide a closed loop with positive feedback By speed mapping the virtual channel to the encoder it is possible to apply speed averaging using the BT command This averaging then filters out any encoder disturbances and the print drum channel can then be mapped to the now steady virtual channel This use of a virtual channel can be extended to applications where a servodriven machine has to be synchronised to the motion of a large conveyor which because of its size will not necessarily be running smoothly Providing the amount of speed averaging is not excessive these variations in conveyor speed ca
25. display reference error can be used in the mapped state The speed and acceleration commands may be entered while in mapping but have no effect on the slave motor The values entered are however stored for future use in any later move commands Copyright 1995 Quin Systems Limited Page 67 PTS User s Guide Revision 2 5 4 Saving Maps Saving maps is achieved in exactly the same way as saving any other parameter sequence or profile by using the Save parameters command as described in Section A of this manual The same precautions have to be taken because when the command is executed all parameters are saved including all the maps that have been entered As the maps can contain a large amount of data the save operation may take considerably longer than previously Only the map positions entered are stored so if a map step of greater than one is used while entering the map then much less non volatile memory space is used For the standard multi axis PTS systems each entered point uses 2 bytes of non volatile memory and the system has a maximum of approximately 30 000 bytes of free memory when switched on The working points are calculated when the map is transferred or first executed the limit then is 30000 bytes each axis for expanded maps The MiniPTS uses 4 bytes per entered point to a maximum of about 20000 bytes of memory in total and 10000 bytes per map no expansion occurs up until an interpolation at run time The
26. in R to L direction Set jog speed then run Machine inching If not printing make sure CH2 not mapped Correct sense of tension loop amp integral Compensates for size of target Set jog speed then run Machine inching If not printing make sure CH2 not mapped Machine stopping Stop machine when F3 released Turn off integral gain Machine stopped E stop contactor out Enable drive for RH spool Enable drive for print cylinder Enable drive for LH spool Speed mapped to encoder Prevent any referencing CH2 MW00010000 SM2775 7958 XMO0 Speed map to match web speed MSG 4 CH3 SS8000 CH1 SS8000 CH1 MI1 7 CH1 ST AM1 AW11110001 XMO CH1 EI1 7 MSG 1 CH1 DC100000 CH1 ST AW11000001 SS 1000 XMO CH1 DC40000 MSG 2 CH1 DC40000 CH3 SV8000 CH3 VC CH2 WI11 1 WI1 1 WI1 1 CH3 ST CH2 ST SV 1000 CH2 VC WI11 14 WI1 1 ST Page 96 Calculating start up ratio Slow speed for start up calculation Slow speed for start up calculation To prevent tension errors Calculate ratio To allow tension errors Aligning tension arm High decel for small decel distance Accurate alignment Normal decel value Driving to print drum proximity For normal running Slow speed for initialising Run web forwards right to left Wait for prox to switch on Stop web Take out of mapping Drive off proximity Copyright 1995 Quin Systems Limited Revision 2 C
27. n and display its state System Command Comments gt Read all inputs 12345678 Line numbers O 1 1 1 1 1 1 1 Input line status 0 low 1 high EEMEEEEE Line maskstatus M masked E enabled gt Page 40 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 9 7 Using Inputs in Sequences It is often very useful to be able to scan an input in a sequence before commencing with the next action This reduces the number of input lines necessary as one line can be used for checking at different stages in the sequence If the line is scanned only at the relevant time then there will be no inadvertent triggering of a function Using an input line in this manner is called wait for input and can be put into any sequence Example nt Wait for input n to go high ve 24 V or low ve 0 V The use of wait for input can best be described by way of an example Consider the starwheel example described earlier Filling Empty cans gt Coe gt Full cans ga The indexing starwheel QO Initialise position First can enters First index 2 Wait for filling lt First can exits to complete Second index Wait for filling of second can Copyright 1995 Quin Systems Limited Page 41 PTS User s Guide Revision 2 The following sequences and parameter values could be used SB 13200 Set the machine cycle length to 13200 counts 4 x 90 indexes of 3300 counts each
28. no sudden changes in the motor speed Velocity SV 2000 Distance total area 10000 counts 2000 Time Copyright 1995 Quin Systems Limited Page 19 PTS User s Guide Revision 2 3 4 5 Setting the Position Window If the motor stops with the M prompt still being displayed without returning to the gt prompt the PTS is reporting that it cannot complete the move to within the range set by the set window command The set window command does not affect the accuracy of the move but simply prevents the next operation following the move from being carried out until the motor is within a set number of counts of the position requested To return to the normal prompt gt then type either or The value of the window can be changed but only in privileged mode The command has the following syntax nn Set the position window to nn counts Example 12 Set the window on the final position to be 12 counts default 10 The incompletion of a move often happens if you have forgotten to type in after switching on the PTS so that the position offset is larger than the window allows Page 20 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 5 Error Handling If for any reason the move cannot be fully accomplished one of several errors may have occurred 3 5 1 The Concept of Position Following Error If during the move the short error message G appears or the l
29. output is simply proportional to the diameters or circumferences of the pulleys Slope pulley ratio Slave Slave position Master Master position The Software Gearbox defines the ratio between the input master axis and output slave axis in exactly the same way The circumference of the either the master or the slave axis has already been used before in Section A to define a cycle This is called the bounds value For example one cycle of the input gear master must complete at the same point as one cycle of the output gear slave even if the cycles are not the same length If the cycles are the same length then the gear ratio is 1 1 or unity NOTE If the resolution or gearing of the encoders is different for each axis this MUST be taken into account when determining the BOUNDS of the master and slave axes to achieve the required ratio The bounds as before are used to set the cycle length in terms of encoder counts The master and slave cycles can be represented by the axes of a simple graph whose lengths are equal to their respective bounds The increments along the axes will therefore be encoder counts starting from position zero in each case and ending at their respective bound values The graph thus defines the relative positional relationship between the 2 axes A fixed ratio between a master and slave is given by a straight line on the graph Slope ratio Slave position Master position
30. program for a PTS Controller MAP A textfile containing a list of position values for use as a map table PRO A textfile containing a list of position values for use as a profile table PAN A textfile containing an uploaded configuration for the operators panel A full description of the content and structure of each filetype is given later Before developing any PTS software on the PC create a specific directory for each application in order to group all the files together and thereby keep them separate from any other work This will then allow the 8 character filename to be more explicit Reserve the last 2 characters in the 8 character filename for the program version number Keeping previous versions allows backtracking If for example the application is for a printing press the initial PTS program filename might be PRINT_00 PTS A subsequent version of the same program would then be PRINT_01 PTS 7 3 Maintaining a Program History As an application is developed the application program will necessarily undergo a number of changes These changes may be additions modifications or fixes to problems It is suggested that the Program History section of the program file PTS is maintained conscientiously as the application is developed Page 78 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 7 4 Getting Started The following step by step procedure is suggested as being the best way to program the PTS syst
31. rather than linear and it is difficult to place limit switches appropriately then the motor should be disconnected from the mechanical system This is assuming that the encoder is mounted on the rear of the motor such that closed loop control may be maintained Without limit switches in place it must be expected that the motor could run at full speed at any time until all the settings have been made Once setting up is complete the motor can be reconnected to the mechanical system Encoder Ballscrew oe BP a a Limit switch 1 Limit switch 2 The PTS has digital inputs digital outputs either per axis or shared between 4 axes Any inputs on a given controller module can be used for limit switches for its axes The command to define a limit switch function on an input is f nt Define a limit switch input The limit switch may be activated when the input line goes high ve or 24 V or goes low ve or 0 V Examples 6 This defines a limit switch on input 6 active low 7 This defines a limit switch on input 7 active high If the limit switch is activated the PTS switches to the motor off state removing torque to the motor A relay contact in the PTS also closes when it goes to motor off and this can be wired to a brake or drive inhibit signal if required The Ln n line number limit switch detected error message is then di
32. relay can be wired to a brake or to the enable input on the drive amplifier so that the motor is disabled when the PTS goes into the motor off state Page 22 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 6 Differences Between Linear and Rotary Machines Two pulleys connected by a lug belt is a simple example of a rotary machine The motion of the motor can be continuously in one direction Lug Da C Lug Pulley A ball screw mounted on the end of a servo motor is an example of a linear machine The motor is constrained to operate only within the length of the screw Ballscrew an The count range of the move commands of 4 000 000 counts is usually more than adequate for most linear systems For a rotary system though if you had done thousands of forward moves and you then wanted to return to the original reference zero position you could well be out of range As most rotary actions repeat themselves on a cyclic basis it is reasonable to assume that if you wish to move back to zero position you only need to move to the zero position in the current cycle This is certainly the case with the lug belt example In a typical example of a belt having three lugs the machine cycle can be defined either as one index length 1 3 of the belt rotation or a number of indexes In this example three indexes make one complete rotation of the belt You need to set t
33. the bounds on the lug belt are set to cover 3 lugs then it is important to only correct on every third lug not on every one The maximum range of counts around the boundary within which correction will take place is set with the command The command also sets the maximum correction value allowed nn Set range around boundary to nn counts The limiting function is enabled with by setting bit 1 to 1 Example 11 Set auto correction on with bit 0 and limit the maximum correction to with bit 1 1 Set auto correction on with bit 0 as before with values exceeding being discarded Any reference errors larger than will either be ignored or the PTS can correct up to the maximum value set by and wait until the next reference signal to apply the remainder of the correction This function is enabled by setting BIT 1 of There are many functions and options with referencing which are described in more detail in the PTS Reference Manual Please refer to the section on Reference Commands Page 56 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 4 Section B Multi axis Control 4 1 Scope of this section This section of the manual refers to the multi axis systems from the four channel MiniPTS to the 48 channel PTS 12 and in particular covers the multi axis or multi channel capabilities Familiarity is assumed with the single channel operation covered in section A All prompts fo
34. until end repeat or abort AX Copyright 1995 Quin Systems Limited Page 25 PTS User s Guide Revision 2 In order to carry out 5 indexes of the lug belt the following sequence could be used System Command Comments MR7500 RP4 Index once and repeat 4 times 5 in total Index 1 Index 2 Index 3 Index 4 Index 5 Finished V 65 555 The above sequence will make the motor perform 5 indexes of either a triangular or trapezoidal shape depending on the velocity or acceleration previously selected The sequence can be up to 255 characters long which allows many commands to be executed automatically one after another A typical example is using a forward and backward repeating sequence to make the ballscrew mimic a cam driven reciprocating motion Example SA100000 SV20000 MA12000 MR 2000 SV3000 MAO RP2 This sequence also includes the setting and resetting of the velocity so that the forward and first part of the reverse is at high speed and the remaining return travel is at slow speed The cycle then repeats twice more going forwards fast and subsequently slowing down SV 20000 Forward 12000 Velocity Return to zero at SV 3000 Reverse 2000 Next cycle Page 26 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 7 2 Display Position Although the PTS always knows where it is it is often useful to display the current position on the terminal The comm
35. H2 RW00001000 RM1 IN CH2 RV5 RW1 PTS User s Guide Initialise to proximity Running referencing commands IF NEW 1 XS10 EL XS201 Calculate new map if required Continuation of initialisation after map generation ES201 IF NEW 1 amp amp MST 0 MSG 15 BK Stop if new map not correct NEW 0 New map not required next time CH5 SB MSB Set new master bound MSG 1 Aligning tension arm CH1 ST AW11000001 SS 1000 XMO Accurate alignment CH2 MP MSB MW 1 SM1 1 Tell slave new bound master bound then map POS gt CH2 MB POS MSB 360 To allow CH2 phase change as degrees MSG 5 Machine initialised Autostart Sequence ES255 SPD DSP Set required speed to default speed CH1 AYC AC Current set point CH1 DEA DA Current DA CH1 ML3 Fixed master slave relationship CH2 ML5 Fixed master slave relationship CH5 ML4 Virtual master slave always mapped to 4 CH2 RM1 Referencing required on print drum CH4 RM1 Referencing required on encoder PEC NEW 1 Force new map generation DEC 9000 Declare value for DEC MST gt Continue map generation INI gt XS200 To initialise machine INC gt XS 150 To inch start stop machine RUN gt XS100 Start machine STP gt XS110 Stop machine SPD gt CH3 S V MAX SPD 100 To set speed as of maximum TEN gt CH1 AC TEN 9 400 CH3 AC TEN 9 400 REG gt NEW 1 Force map generation during init next time LEN gt NEW 1 Force map gener
36. If these variables are already defined as trigger variables then the commands attached to these trigger variables will be executed on startup This generally is not required 11 ML commands can be in the autostart sequence provided the channel bounds are fixed parameters But note that ML for a differential map has a clean up function for wrapped around bounds so may then be needed later 12 Use upper case for the PTS program in the PTS file It is often necessary to search through a program file for occurances of specific commands By forcing the search to be made specifically on upper case the search will not select any comment characters Copyright 1995 Quin Systems Limited Page 83 PTS User s Guide Revision 2 7 9 Programming Tips 1 If an operation is required to take place at a particular point in a machine cycle configure a position trigger output to switch on at this point and wire the output to an input on the PTS Configure a defined input on the PTS to execute a command or sequence when the input becomes active This approach is far more efficient than using a wait command and also allows phase advance to be applied to the position trigger output refer to the PA command in the PTS reference manual for more details Later firmware will allow the use of a virtual i o bit 2 If the display mode DM is not showing any reference errors when reference signals are known to be coming in check to see if the SR reference w
37. Programming Operator s Panel P parallel operation parameter save password pause PC PLC control PM PO position control position error position mapping position offset position switch Revision 2 11 61 65 51 68 66 15 45 21 8 9 15 21 38 72 22 9 16 45 16 16 23 16 65 58 30 67 31 79 13 13 29 10 81 88 60 13 28 34 43 44 21 63 20 43 Copyright 1995 Quin Systems Limited Revision 2 position trigger output position window power supplies privileged mode product registration profile velocity Program Structure Programming Tips prompt characters gt I x PTS Toolkit software PV R R error message RD read data from nvm read input s recursion reference correction reference error reference input reference mode reference options reference position reference word relative position format relay repeat command line repeat in a sequence restricted command reversed encoder RI RM RO rotary machine RP runaway RW S SA save parameters saving input line definitions maps Copyright 1995 Quin Systems Limited 47 12 32 22 13 33 14 18 13 43 20 38 37 52 50 77 84 14 16 67 76 50 13 37 37 40 31 55 54 53 54 55 53 55 47 38 25 30 37 40 54 54 23 25 56 50 33 37 68 PTS Users Guide sequences 33 SB 24 44 70 SE 21 separator 25 set acceleration 18
38. Quin Controller is unlike that of a conventional high level program written in C for example and its execution is certainly unlike that of a PLC program This radical approach to programming has been taken to provide a number of benefits It is important to undertand the hows and whys of Quin programming before actually spending any time developing an application A failure to understand these basics could result in an application program being written which provides the necessary functions but fails to provide sufficient positioning accuracy or response time for example A Quin motion program is based around the use of 2 letter mnemonic commands which will have been introduced earlier in this User s Guide These commands can be used to specifiy controller settings which either remain constant throughout the application or can be made to execute as and when the application demands Some of these commands apply to individual channels axes whereas others apply globally to the complete PTS system The 2 letter mnemonic commands can provide both low and high level functions A single command can be used for example to simply change the state of a digital output whereas another single command can be used to initialise a machine axis which requires specific motions input recognition and internal counter adjustments being made automatically It is important to fully understand the range if not the specific details of the b
39. able on the system is 1 256 second about 4 ms The profile velocity in ticks per second is set using the PV command In this example we shall use eight time steps for the complete profile giving a time interval of 1 4 second per step This corresponds to a profile velocity value of 4 The intermediate velocity values along the required curve can be calculated in this case since the required profile is a known mathematical function However they are in general quite arbitrary Velocity counts second 10240 9461 7241 3919 o 0 25 0 50 0 75 1 00 1 25 1 50 1 75 2 00 Time seconds The required profile table entries represent the area under the curve in encoder counts for each of the eight steps These areas can be determined by integration but only from a mathematical function A simpler technique numerical integration can be used with arbitrary profiles as well We shall use this technique here Velocity counts second 10240 9461 7241 3919 o 0 25 0 50 0 75 1 00 1 25 1 50 1 75 2 00 Time seconds Page 48 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide The approximate area for each step is equal to the average velocity over the step multiplied by the time interval for the step This gives the following results Step number Value 490 1395 2088 2463 2463 2088 1395 490 Total distance 12 872 counts ONNNBWNYN Calculation 3919
40. and Rotary Machines Single Line Sequences Sequences That Can Be Saved Linking the PTS to External Switches or a PLC Speed Control Profiles Automatic Referencing 4 Section B Multi axis Control 4 1 Scope of this section 4 2 Description of the Multi axis Systems 4 3 First Steps 4 4 Changing Channels 4 5 Simultaneous Motion 5 The Programmable Transmission System 5 1 Software Gearbox 5 2 Maps 5 3 Setting Up the Software Gearbox 5 4 Saving Maps 5 5 Mapping 5 6 Software Line Shaft 6 Tension Measurement Considerations 6 1 Tension Control using a Dancing Arm 6 2 Tension Control using S wrap rollers 6 3 Tension Control using a Linear Roller 6 4 Tension Control using a Loop 6 5 Tension Control using a Loadcell 7 The Programming Environment 7 1 The Program Structure T2 Filename Conventions 7 3 Maintaining a Program History 7 4 Getting Started 7 5 Continuing Work on an Existing Application 7 6 Off line Program Editing Jot On line Programming Procedure 7 8 Good Programming Techniques 7 9 Programming Tips Copyright 1995 Quin Systems Limited PTS Users Guide Page 1 PTS User s Guide Revision 2 8 Discussion of Worked Examples 86 8 1 Worked Example 1 86 Page 2 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 1 Introduction The of this manual is to give the user an accurate but concise picture of the scope of the PTS Programmable Transmission System and its application to industrial machine
41. and to display the position value is and it can be typed at any time whether stopped or moving System Command Comments gt MA10000 Move to position 10000 counts from zero M Moving gt DP Display position 10001 Current position its accuracy depends on mechanics gt MAO Return to zero M Returning DP Display position while moving 6321 Current instantaneous position M gt At zero position can also be included in sequences like the previous example SA100000 SV20000 MA12000 MR 2000 DP SV3000 MAO DP RP2 The above sequence will print the position of the motor at approximately 10000 counts at the end of the forward move and again when it has returned to zero This method can be used as a visual check on the accuracy of the machine Remember that the position is displayed as soon as the motor is within the set window range at the end of the move If the set window is a large value then the position reading displayed by the function may differ from the target position of the preceding move command by up to the window value Copyright 1995 Quin Systems Limited Page 27 PTS User s Guide Revision 2 3 7 3 Putting In a Delay It is often useful to put a dwell or delay in a sequence of motions For example if a starwheel is being used to index cans under a filling head putting a delay between successive indexes of the starwheel allows time for the filling operation to complete before the next i
42. ap 1X Channel is mapped to channel 2 The command may be used to scale the output of a map table before it is used for the slave channel For example the master encoder above might have 2500 line resolution against a slave of 1024 Example System Command Comments 1 gt SM1024 2500 Scale the slave axis channel 1 1 gt XMO Start mapping 1X Mapped Page 72 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 6 Tension Measurement Considerations The principle of tension control using the PTS and the Tension Controller itself is relatively straight forward The material whose tension is to be controlled is driven both before and after a device which is used to measure the tension Motion software in the controller speed matches one drive to the other with a speed ratio The tension measurement is compared to a set point and the tension error is then used to modify the ratio to correct the arm position The example in section 8 includes axes linked for tension control and illustrates the programming commands The ability of the machine to maintain a consistent tension depends on the performance of the machine in driving the material before and after the tension measurement The ability of the machine also depends on the way in which the tension is measured The following considerations should be made when designing a tension system There are 5 basic ways in which tension can be controlled Each is described b
43. arefully If the map requires any short or steep acceleration ramps choose a map step value which allows the ramp to be defined with several points If only a few points are used the acceleration ramps become a succession of step changes in velocity Increasing the number of points unnecessarily will use up too much memory 11 Make sure that channel commands are correctly used prior to I O commands On the PTS the I O is allocated per channel and II CO SO commands for example must be preceeded by the relevant CH command This is less important with the Mini PTS where the I O is global Many input definitions like DR and output definitions like PO still require the use of the correct channel command 12 Use a short wait command eg WT32 between the PC command and the ID This will allow the drive time to enable and for the motor to hold its position and be stopped before the ID command calcuates the require offset to the command signal to provide a small position error at standstill 13 A logical AND can be performed on two or more inputs by using two II commands For example CH 1 II1 II2 VC will run channel 1 at a constant speed if both inputs 1 and 2 are high 14 A logical OR can be performed on two or more inputs by using the II command on separate lines For example CH1 Il1 VC BK CH1 I1I2 VC BK Channel 1 will run at a constant speed if either input 1 is high or input 2 is high The BK command at the end of the fir
44. ation during init next time CH3 II1 8 MSG 10 EL MSG 14 Startup message Input Definitions CH2 DR1 1 Reference input for print cylinder prox CH3 DI1 7 GF GX XS99 Tension error CH3 DI1 8 GF MSG 10 If E stop contactor drops out CH3 DI1 84 MSG 11 E stop released Output Definitions CH1 AE1 Tension error output GO To take out of edit mode Copyright 1995 Quin Systems Limited Page 97 PTS User s Guide Revision 2 Page 98 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide Index prompt 9 delimiter gt prompt 9 demand offset 1 1 mapping 72 DF DI A display input state AB 15 25 45 measured velocity abort 15 position absolute position format 47 reference error absolute zero position 53 tme acceleration 18 Be alignment move 67 ee analogue offset 10 PE auto correction 55 PR drive inhibit auto referencing 53 i autostart sequence 58 orivesoise DT B DV dwell binary number 55 bounds 24 44 45 53 62 70 E brake 8 15 E error message C EM emergency stop cam switch 43 enable relay CH 59 enter change channels 59 map changing velocity while moving 18 46 ee clear output 36 EP clock set 7 error messages CO 36 E combined sequences 31 F command string 25 G cycle length 24 43 52 53 62 L cyclic system 23 U D error reporting dancing arm 73 error signal aati 52 errors during a move DE 38 ES define execute error output 38 command on external signal input function 35
45. b element of the motion if possible This greatly simplifies programming the system and the use of the input and output lines Copyright 1995 Quin Systems Limited Page 43 PTS User s Guide Revision 2 The cycle can be redefined in length by using the set bounds command It was previously set to 13200 counts for the starwheel application If the set bounds is now set to 3300 counts the absolute position returns to zero after each 1 4 turn of the starwheel E o i a Position zero Position 3000 Position 3300 Position 3320 gt 0 gt 20 Output line 1 cycle gt 0 20 3000 3300 20 gt 0 3 9 9 Position Trigger The command for defining the filling inhibit output signal is position trigger nt activate position deactivate position where n is the output line number and the two position values define the range of positions over which the output signal is true Example The starwheel again 1 20 3000 Set output line 1 low 0 V between absolute position 20 counts and absolute position 3000 counts NOTE This definition has exactly the same meaning as setting output line 1 high between absolute positions 300 counts and 20 counts Once a position trigger output is defined it will remain active until it is undefined It does not matter what motion commands are subsequently used the position trigger activates at the predefined positions To undef
46. boundary with the occurrence of a signal from the reference input in this case the proximity detector Copyright 1995 Quin Systems Limited Page 53 PTS User s Guide Revision 2 3 12 3 Measuring Reference Error It is useful to first measure what reference error may occur This is achieved by activating the auto reference facility with the command 1 Reference mode on This switches on auto referencing and enables current reference inputs This is described more fully later This mode is switched off with the 0 command Once is on then any motion can be started While the motor is running the most recently measured reference error can be displayed with the command Display last measured reference error in counts The reference error is defined as the difference between the expected encoder zero point as defined by the bounds value and the position where the reference input was detected the proximity detector The measured error is automatically updated and the value stored every time the proximity detector is triggered allows you to observe the value stored Example System Command Comments gt RM1 Enable auto referencing gt VC Set belt running at constant velocity V DF Display last measured reference error 0 V DF 2 etc V V RMO Disable auto referencing V ST Stop gt NOTE and other reference commands can also be entered at any time even while the motor is moving Page 54 Copyright
47. commands while moving limit switch input 8 map position trigger output 44 Sequence reference input 12 external switches delay 28 Copyright 1995 Quin Systems Limited 25 10 54 35 40 69 27 54 21 27 12 10 69 28 65 15 22 65 51 29 51 13 21 13 22 37 38 38 21 29 35 46 54 67 67 70 29 34 Page 99 PTS User s Guide F F error message fault condition filename convention filtering out extra reference signals FM following error free memory G G error message I I prompt ID IN initialise demand offset initialise position L L error message LI limit on auto correction limit switches line shaft linear interpolation linear machine linear ratio link slave axis to master axis list input and output definitions sequence loop LS lug belt M M prompt MA machine cycle map alignment move link size limit step word Map Generator map zero Page 100 51 13 38 78 56 68 21 51 21 14 20 14 10 14 39 56 12 65 23 64 66 39 32 25 32 23 16 16 23 marker signal master axis master map division memory space ML MO motor errors motor off motor off relay motor runaway move absolute at constant velocity relative move profile move range MR MS multi axis system prompts multi line sequence MW N nested sequences new application NM normal mode numbered sequence O offset On line
48. dent sequences to form more complex operations rather than writing one large sequence Example System Command Comments gt ES3 Enter sequence 3 S3 XS1 XS2 RP Execute sequence then sequence 2 and repeat indefinitely S3 lt CR gt End sequence This nesting of sequences calling sequences from within sequences also has the benefit of allowing small sections of the complete operation to be changed without having to re enter all of the commands for the complete sequence CAUTION While it is quite possible to write a sequence that calls itself this is not allowed This is because each time the command is executed the system pushes the current sequence state on the stack to allow it to return to this state when the new sequence ends If the new sequence called is the same as the current sequence then it never ends because it again calls itself and eventually the system runs out of memory This is called infinite recursion Copyright 1995 Quin Systems Limited Page 31 PTS User s Guide Revision 2 3 8 3 Listing Sequences Having now entered the sequences it is useful to list them to remind yourself of their contents The command list sequence is used System Command Comments gt List sequences currently stored in the PTS Sl S2 S3 gt To review the contents of specific sequences System Command Comments gt 1 List sequence 1 S1 MA3300 WT128 RP3 gt Ready 2 List sequence 2 S2
49. der within the PTS file During a program download from the PC the PTS will accept sequences in any order However to make the program easier to read and to be able to find specific sequences easily in a listing the PTS sequences should be written into the file in ascending order 3 Group the sequence functions together Up to 255 sequences can be defined in a PTS Since an application never needs this many it is useful to use this overall range of sequence numbers to allow specific ranges to be used for specific functions For example sequence numbers to 90 could be used for product selection sequences 91 to 99 as error sequences 100 to 199 for starting inching and stopping and sequences 200 to 255 for initialisation and power up The allocation is arbitrary and should suit the application but the grouping makes for a tidy and easy to read program Sequences are able to execute other sequences It makes sense to allow these sequence calls to be within the group to prevent the sequence executions jumping backwards and forwards within the PTS file 4 Use 3 character variable names Although the PTS will accept single character and two character variable names the variable useage is more meaningful if 3 characters are used 5 Comment why the program is written the way it is Using the 2 letter mnemonic commands makes the program easy to understand because the choice of mnemonics reflects the function of the command It is possible to und
50. design The manual is designed to be used by operators and engineers as a guide to the PTS system although it does expect the PTS to have been correctly installed A full guide to the installation procedure is outlined in the PTS Installation Manual and the MiniPTS Installation Manual The manual provides a guide and a quick reference but is by no means an exhaustive document A full reference and detail of all the functions is provided in the PTS Reference Manual and the MiniPTS Reference Manual Copyright 1995 Quin Systems Limited Page 3 PTS Users Guide Revision 2 2 General Description The PTS provides a novel method of designing machines The PTS range controls from 1 to 48 servo motors depending on the model and can be used to replace commonly used mechanical components such as geartrains clutches brakes and indexing boxes The required motions in the machine can now be driven directly by servo motors resulting in stiff low inertia mechanics capable of outstanding performance with high accuracy Unlike a traditional gear or chain transmission all end motions can be programmed to produce any uniform or cam like action within the capability of the motor used Recent developments in servo motor technology have increased this capability to new heights making motions with very high accelerations possible in a continuous machine cycle Page 4 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide This ma
51. e MST which is written to by the map generator software an error message is reported and the sequence execution is aborted 8 1 8 Conditional Program Flow The IF statement is used in a number of sequences to select appropriate error messages to call specific sequences and to pause sequence execution until a particular requirement is met Sequence 112 tests the machine speed by using the IF statement to keep the test looping using the repeat command until the speed is less than a critical value Example Program 1 TENRIGO2 PTS Channel Definitions 1 Right Hand Spool Speed mapped to CH3 with tension loop 2 Print Cylinder Position mapped to CH5 with map1 3 Left Hand Spool Master 4 Encoder Driven by web 5 Virtual axis Speed mapped with averaging to CH4 Program History Date Initials Modification Mar 95 GCB First written to specification Apr 95 GCB Tuning modified Tension alignment problem solved Maximum speed increased Jun 95 GCB Wind on function added th te He OH OH OH Copyright 1995 Quin Systems Limited Page 91 PTS User s Guide Operator Panel Variables DIR DSP ECM INC LEN MAX PCM POS PRI REG RUN SPD STP TEN HH OH OH HH HH HH HH HH OH Revision 2 Web direction 1 L to R Display page 1 field 3 Default Speed Encoder counts mm x100 Inch start stop machine Print length mm Maximum speed counts s Print counts per mm x100 Position o
52. e of the material around the roller can change more with arm rotation This can be reduced by positioning the idler rollers further away from the dancing arm roller This though adds to the amount of space required by the overall system Copyright 1995 Quin Systems Limited Page 73 PTS User s Guide Revision 2 Whatever length of arm is used the arm itself will only rotate through a fraction of a revolution If the potentiometer is directly driven at the arm pivot then the voltage swing will only be a proportion of the overall voltage across the potentiometer The PTS will accept a swing of up to 10V This swing should be as high as possible within the 20V limit to provide the best resolution of the arm position This could be achieved by applying a large voltage across the potentiometer such that its resultant angular movement producesa healthy swing To make use of the full range of the PTS s AtoD a bipolar power supply should be used If one is not used then the arm resolution is immediately halved since the input can only swing through O to 10V If a large voltage is applied across a potentiometer to provide a good output swing some over voltage protection should be fitted to its output to prevent anything outside of 10V being applied to the PTS input This could be achieved using Zener diodes and resistors A 10V 1 3W Zener diode with a 1k resistor will suffice An alternative way of increasing the voltage swing is to gear up
53. ed to an accuracy of 2 decimal places to provide sufficient accuracy in the expressions in sequence 10 a scale factor of 100 is used in the panel configuration Refer to the Operator s Panel Reference Manual for more details on scaling A value of 65 79 for example specified through the panel will write the value 6579 to a variable when a scale factor of 100 is used Having scaled the value of one of the variables in this way it is then necessary to divide the expression by the same scale factor to produce the correct result This division is deliberately done at the end of the expression in order to provide the highest accuracy See tip number 6 Copyright 1995 Quin Systems Limited Page 87 PTS User s Guide Revision 2 The map generator software takes a few seconds to calculate a new map it runs at a lower priority than motor control so takes longer if the motor task is busy It is important to know when the generation is complete Variable MST is used for this purpose When the map generation is complete the map generator software writes to MST either with an error code or with a value of 0 if the generation was completed successfully By setting MST up as a trigger variable a sequence can be made to run when the map generation is complete In this case sequence 201 Sequence 10 also sets MST to 1 prior to running the map generator This value can never be set by the map generator itself and hence the value of MST must change T
54. elow together with a list of the pros and cons 6 1 Tension Control using a Dancing Arm A dancing arm in its simplest form consists of a single roller supported and free to rotate at one end of a cantilevered arm which itself can pivot about its other end relative to the machine frame A torque is applied to the arm It is this torque which is resisted by the material and which therefore produces its tension This is probably the simplest mechanical solution and probably the lowest cost solution The tension signal can be produced from a potentiometer which is driven at the arm pivot by its rotation As well as providing tension to the material the movement of the arm can be used to provide a buffering or accummulating effect In the latter case the change in tension in relation to the arm angle can be kept small This can be achieved by using a counterbalance weight a spring whose variation in length is small relative to its length an air spring or a hair spring The length of the arm will depend on how much buffering is required or whether the arm position needs to be respecified while the machine is running in order to provide a new tension set point The swept volume of an arm can be significant a dancing arm is not the most compact solution The amount of arm movement also depends on how well the material can be driven or how significant are the eccentricity or slip effects Smaller arms are less linear than larger arms since the angl
55. ems It allows the PTS to be programmed either offline or online and makes full use of all the programming environment features 7 4 1 Off line Programming Procedure Start PTS Toolkit running Refer to section xx above if required Once PTS Toolkit is running select FILE OPEN TEXT FILE PTSmotion will present a dialogue box allowing the required text file to be selected The procedure at this point will depend on whether a new application is being started or whether an existing application is to be worked on 7 4 2 Starting a new Application If a new application is being started select the file NEW PTS from the Application Pack floppy disk supplied This file contains the basic structure for a new application program Since this file will be required again for subsequent applications don t work directly with this file Instead save it with its new application name e g PRINT_00 PTS Make sure that the directory for the application programs exists If the directory doesn t exist at this point switch to the windows FILEMANAGER and create the directory Switch back to PTS Toolkit and save the file using the commands FILE SAVE AS The SaveAs dialogue box will appear Select the new directory and specify the new filename e g PRINT_00 PTS in the filename box Note that the version number has been set to 00 Copyright 1995 Quin Systems Limited Page 79 PTS User s Guide Revision 2 7 5 Continuing Work on an Existing
56. en entered points can be entered before or after entering the profile and may even be changed while the profile is running This is performed by the profile velocity command 3 11 4 Free Memory A number of different profiles can be entered into the PTS depending on the amount of free memory each point uses 4 bytes of memory It is therefore useful to find out how much memory space is available The command to display the free memory space is the free memory command Example System Command Comments gt FM Display free memory available 13677 PTS returns number of bytes available gt Copyright 1995 Quin Systems Limited Page 51 PTS User s Guide Revision 2 3 12 Automatic Referencing 3 12 1 Introduction When the PTS was switched on the position needed to be initialised in order to reference the encoder counts to a datum position on the machine It is very useful to be able to continually check the encoder position against the datum without stopping the motion This gives a number of benefits e The encoder signal can be continually verified to check correct operation and if required apply automatic correction If the cycle length of the machine does not quite match an exact number of encoder counts then the PTS can apply automatic correction to maintain alignment with the datum If instead the datum used is on the product rather than on the machine then the cyclical motion can be kept in continual align
57. erstand what an uncommented program is doing but not why it has been written in such a way The comments for the sequences and individual sequence lines should describe why specific parameter values and bit settings have been used 6 If the application uses a PLC then use it to handle the logic side of the application A PTS is able to handle logic and can perform motion control and logical operations concurrently However it simplifies the system if the logic is grouped into the PLC and the motion control and real time PTS operations are performed by the PTS Page 82 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 7 Use digital I O between a PTS and a PLC to handshake Where a PLC is used in an application to trigger digital inputs on the PTS to perform specific motion tasks allocate a PTS output to signal back to the PLC when the PTS is busy actioning the request and therefore when it is complete Serial data links such as Modbus or Data Highway are of value for initial setup but are too slow in this context for most real time controls 8 On the PTS as opposed to the Mini PTS select the useage of specific inputs carefully Choose inputs on a specific channel to be configured with defined inputs which run commands required on that particular channel For example if the speed of channel 2 needs to be incremented choose an input on channel 2 to be configured with a defined input to execute the IP command Some comma
58. f print rel to mark Print option O NO 1 YES Setup menu 1 Operation Setup menu 2 Engineering Function key F2 Setup menu Operation Setup menu 2 Engineering Setup menu 2 Engineering Display page 1 field 4 Setup menu Operation Display page 1 field 2 Registration pitch mm Setup menu 1 Operation Run machine Function key F3 Current Required Speed Display page 1 field 1 Stop machine Function key F4 Tension set point Display page 2 field 1 Message List Unqueued using associated variable MSG 1 CeAIADUMNHWNY 9 10 11 12 13 14 15 16 17 18 th tH HH HH HH HHH HHH HH HOH PTS Variables AYC DEA DEC F00 FO1 F02 F03 M00 M01 M02 M03 M04 M05 NEW NUM S00 S01 S02 S03 S04 tH OH HH HH HH HH HH HH HH HH H Page 92 Aligning tension arm Driving to print drum proximity Calculating print drum profile Calculating start up ratio Machine initialised Machine running Machine inching Machine stopping Machine stopped Emergency stop contactor out Emergency stop released Tension error high limit reached Tension error low limit reached Machine power up complete Error generating map Channel 1 motor error Channel 2 motor error Channel 3 motor error Current reading of AC Current reading of DA Snapshot speed of CH3 used in stopping Function
59. further Copyright 1995 Quin Systems Limited Page 9 PTS User s Guide Revision 2 3 3 5 Offset in the Drive Quite often there will be a certain amount of analogue offset in the drive amplifier This is difficult to adjust out permanently However the PTS is able to measure the effect of the analogue offset and adjust the position offset accordingly This is achieved by using the command If this command is always entered after the unit is switched on then the offset in the drive will not matter even if it has changed in between times Page 10 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 3 6 Preparing for Initialisation When the PTS is switched on it assumes that where it is switched on is the zero position until told otherwise For most applications it is necessary to initialise the encoder to some external reference point This can be the marker signal on the encoder or a proximity detector detecting a datum point on the machine or product to which the machine needs to reference a Lug belt with Linear encoder with proximity switch reference marker The encoder marker signal is connected to the Z and Z inputs on the encoder connector If some other zero position signal is used then it can be connected to any of digital inputs 1 4 In the following examples input 1 is used Reference input signal from proximity switch o a
60. h bits are set in the analogue word later firmware uses the slave channel values and analogue port for both the measurements The spools are driven at a speed specified by the value of the SS parameter when searching for the high and low limits while calculating the SM at startup This value of SS specifies an angular velocity The web speed and hence the speed at which the arm moves depends on the diameter of the spool The value of SS has been chosen to provide an acceptable arm speed in the worst case when the spool is full The value of DC is set deliberately high to prevent the spool and hence arm running on significantly while decelerating once the high or low point has been sensed The value of SA is also used during these moves The analogue error output facility is enabled using the AE command This output signal in this application is linked back into a digital input on the Mini PTS which has a defined input configured on it in order to run the tension error sequence 99 This allows the machine to shutdown cleanly and to display the appropriate high or low error message on the operator s panel by comparing the analogue input to its setpoint 8 1 6 Referencing A proximity is fitted to the machine to provide a once per revolution once per print cycle signal from the print drum The proximity switches on when the print characters are at top dead centre This allows it to initialise when it is off print Printing takes place when
61. he length of the cycle to accomplish one or a number of complete indexes of the lug belt Each index will be equal to the distance between lugs measured in encoder counts 1 index Copyright 1995 Quin Systems Limited Page 23 PTS User s Guide Revision 2 3 6 1 Set Bounds The command to set the length of the machine cycle is set bounds The set bounds command has the following syntax nn Set the machine cycle repeat length to nn encoder counts If the distance between successive lugs on the lug belt in this example is say 7500 counts then the value of can be set to 7500 counts 15000 counts or 22500 counts etc as required Example 7500 Set bounds value of the position counter to 7500 counts You can carry out the following sequence System Command Comments gt SB7500 Set Bounds Set position bounds to 7500 gt MR7500 Move relative Index the lug belt M Moving gt Index completed gt MR33956 Move Relative Index the lug belt again M Moving M AB Abort Emergency stop gt Stopped gt MAO Move Absolute Move back to beginning of cycle If you use the command MA7500 instead of MAO as the last instruction the lug belt will now move forwards to the beginning of the next machine cycle from wherever it stopped instead of moving backwards to the beginning of the current machine cycle Although this example may seem trivial this setup is the basis for enabling the PTS to recover from an error c
62. ime Copyright 1995 Quin Systems Limited Page 45 PTS User s Guide Revision 2 The velocity can be altered without stopping simply by entering the command while in motion Example System Command Comments gt VC Run at constant velocity forwards V Prompt indicating velocity control mode V SV 500 Change velocity to 500 counts second while moving V DP Display current position 5635 Current position V ST Decelerate to a stop gt Stopped NOTE In fact most commands can be entered while the machine is in motion Speed change is one very frequently used but many others are useful such as display position or read inputs for example Page 46 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 11 Profiles 3 11 1 Calculating a Profile So far in this manual position moves with the or commands have followed a trapezoidal or triangular velocity profile depending on the speed acceleration and distance moved These profile shapes are often not ideal for high performance machinery as the sharp changes in speed cause very high changes in acceleration This leads to excessive vibration and premature wear in the machine mechanics The PTS provides facilities for defining other velocity profiles as well These profiles are user defined and may follow a mathematical function such as a sinusoidal or parabolic curve or may be completely arbitrary This facility is called the Software Cam A veloc
63. indow is active This will filter out the reference signals if they come in outside of the SR window The commands WE DF RP can also give a useful check 3 If the display mode DM is showing too many reference errors per machine cycle and the reference errors are varying check to see if the marker pulse has been configured as a valid reference input with the DZ command Electrical noise or a faulty sensor can give similar symptoms 4 Don t use variables with the following names V1 V2 V50 These are reserved for access from Modbus and Data Highway NUM MST MTR MO00 MO1 M99 S00 S01 S99 SIZ SVMD ASM MSB SSB NPT VSM F00 FO1 F99 W01 W99 These are reserved for use by the PTS map generator Certain functions of the map generator also use A01 A99 B01 B99 CO1 C99 X01 X99 Y01 Y99 Z01 Z99 5 Don t attempt to save parameters on the PTS using the SP command while sequences are being executed or if inputs are changing state It is important to save a coherent set of values fit to run from power up 6 In expressions perform multiplications before divisions Expressions are used to perform arithmetic operations on variables and constants These both hold integer values When a division is performed on two integers any remainder is lost By performing divisions on larger numbers the remainder represents a smaller proportion and therefore the accuracy is improved It is imp
64. ine a position trigger output simply enter the n command without any sign or position values 1 Undefine position trigger on output line 1 Page 44 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 10 Speed Control The PTS can be used as a very accurate closed loop speed controller The velocity control mode produces a very similar motion profile to that produced when a move command has been entered The only difference is that the move has no end point unless one of the stop commands is entered The velocity is measured in counts second and is constantly monitored using the normal closed loop feedback from the position encoder As the encoder is still used in velocity control mode the current position of the motor is continually updated in the normal way If the bounds are set to match the cycle of a machine then however long the machine has been running in mode it can still be stopped and moved to a defined position in the current machine cycle To run the motor at a constant velocity needs to be set to the required velocity as with a normal move command can also be used to preset the ramp rate used when accelerating to the required velocity The command to enter the velocity control mode is Enter velocity control mode Accelerate motor to speed set with and maintain it until it is changed with or one of the stopping commands is entered AB or MO Velocity SV 500 Kea T
65. ing input 1 has already been defined as the reference signal with the command input 2 could be used for the start initialise sequence signal and input 3 as the start index sequence signal PLC PTS Reference Output A Output B Page 34 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 9 1 Defining Inputs The define input command tells the PTS which input line activates a particular function n Define an action on a rising or falling electrical input signal A rising input occurs when the voltage goes from 0 V to 24 V A falling input occurs when the voltage goes from 24 V to 0 V The line number n defines by which input line 1 to 7 the action is going to be triggered This command is restricted so it can only be used in privileged mode Example System Command Comments gt PM Enter Privileged mode Enter Password lt CR gt Press carriage return O K Acknowledgement gt gt DI2 IN Input 2 going from high to low will start the initialisation Input 3 can be defined in much the same way so that the index motion can be triggered externally by the PLC Example 3 MR3300 Input 3 going from high to low will index once Input 3 could instead be made to trigger a complete sequence Example 3 XS1 Input 3 going from high to low will trigger sequence 1 Copyright 1995 Quin Systems Limited Page 35 PTS User s Guide Revision 2 3 9 2 Setting Outputs
66. ion and 2 velocity values 1024 counts second and 1024 counts second respectively The command is used to alter the set velocity and the command is used to change the acceleration or ramp rate for a move The and commands have the following syntax nn Set acceleration This command sets the acceleration and deceleration ramp rates nn Set velocity This command sets the maximum velocity during a move Velocity SV SA SA Time Here are a few examples 2 10000 Set acceleration deceleration to 10 000 counts second 20000 Set velocity to 20 000 counts second If the above moves are now tried again they will take place in a much shorter time Once you have changed and or all subsequent moves are calculated with the latest settings The stop deceleration may also be set 2 15000 Set stop deceleration to 15 000 counts second Page 18 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 4 4 Changing Velocity on the fly A very useful feature which will be explored in other ways later is the ability to change the velocity of the profile while the motor is moving The command is simply entered while the prompt is M Example System Command Comments gt MA10000 Start a move to position 10000 counts M SV2000 Change the velocity to 2000 counts second gt Move completed The maximum speed can be raised or lowered during the move resulting in a stepped velocity profile with
67. ity profile is defined simply as a table of positions against time The PTS allows the user to enter a profile table in either absolute or relative position formats In absolute position format the profile is defined as a list of successive cumulative positions relative to the start position of the profiled move In relative position format the profile is defined as the change in position in encoder counts at each time step relative to the previous position in the table Please refer to the PTS Reference Manual for more details The profile table entries in each case are simply a list of signed integer values in encoder counts The time taken for the PTS to complete a profile is determined explicitly by the number of entries in the profile table and one other parameter the profile velocity which is discussed later The profile is made to execute in a predetermined time by defining it over the required number of steps As an example we shall define a sinusoidal velocity profile over a two second period with a maximum instantaneous velocity of 10240 counts per second This example shows the use of the relative position format in entering a profile Velocity 10240 counts second 0 0 Time seconds Copyright 1995 Quin Systems Limited Page 47 PTS User s Guide Revision 2 The profile period is first divided into a number of equal time steps The profile table requires one entry for each time step The shortest time step us
68. lly a dancing arm without the arm Instead a roller is allow to move vertically and may or may not be counterbalanced This type of measurement can provide a lot of roller movement and is good for accumulation Some form of linear position sensing is required e g an LVDT or a linear potentiometer 6 4 Tension Control using a Loop Tension control also includes situations where the material must remain slack as a loop under its own weight This is to allow product to be transferred from one process to the next if the two processes are not synchronised Feedback on the loop height can be provided by an ultrasonic sensor which can vary the speed ratio in exactly the same way as described above in order to maintain a constant loop height Some material is perhaps too delicate to be wrapped around a roller 6 5 Tension Control using a Loadcell A loadcell is a very accurate way of measuring tension but can be expensive Mechanically it can provide the simplest solution whereby a single roller can be supported on one or more loadcells An amplifier is required to provide a suitable voltage swing This range can be selected within limits but is generally unipolar Unlike any of the tension control solutions above a loadcell does not provide any buffering A small change in speed ratio produces a large change in tension A loadcell should not be considered if the position and hence speed control of the drive motors is not good Copyright 1995
69. machine if not printing ES111 CH3 ST CH1 AW1xxxx0xx MSG 9 Stop machine if printing ES112 CH3 DEC DV CH3 WI1 14 ST CH1 AWOxxxxx0xx MSG 9 Copyright 1995 Quin Systems Limited Stop machine Turn off integral gain Machine stopped Read current master speed IF DEC lt 0 DEC DEC 1 IF DEC gt 8000 CH3 S V8000 IF DEC gt 8000 XS 113 RP Take modulus in case its going backwards If greater than 8000 then reduce to 8000 Wait until speed is less than 8000 Wait until off print then stop Turn off integral gain Machine stopped Page 95 PTS User s Guide Revision 2 Check if master slowed down ES113 CH3 DEC DV IF DEC lt 0 DEC DEC 1 Inch start stop machine ES150 Read current master speed Take modulus in case its going backwards IF INC 1 XS160 EL XS170 Start or stop machine Inch start machine ES160 IF DIR 0 XS162 EL XS164 Use correction sequence for direction Inch start Right to Left ES162 CH1 AW1xxxx1xx CH2 RFO CH3 SV2000 VC MSG 7 IF PRI 0 CH2 ST Inch start Left to Right ES164 CH1 AWOxxxx1xx CH2 RF945 CH3 SV2000 VC MSG 7 IF PRI 0 CH2 ST Inch stop machine ES170 MSG 8 CH3 ST CH1 AWOxxxxx0xx MSG 9 Initialisation sequence ES200 CH3 II1 8 MSG 10 BK CH1 ST PC WT32 ID CH2 ST PC WT32 ID CH3 ST PC WT32 ID CH5 PC XMO CH2 RWO Correct sense of tension loop amp integral Initialises
70. may be before or during the profile execution Example 4 Set time increment between profile points to 1 4 second If the profile velocity is set to a higher number than you have chosen for your table of values then the speed of the profile is increased to a maximum of 256 steps per second For the single axis controller each time PV is increased by one the speed doubles Conversely if PV is set lower the speed is reduced halving each time PV is reduced by one This gives a degree of speed and acceleration control of a profiled motion NOTES 1 and are not applicable to profiled motions 2 Internally the PTS calculates a point every 1 256 second If points have only been entered in coarse increments as in the example then the PTS creates a straight line of points between each point entered The more points entered the more smoothly a curved profile will be followed although more memory space will be consumed Page 50 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 11 3 Enter Profile Once the velocity values have been calculated for the shape required they can be entered using the enter profile command n Enter profile number n Example System Command Comments gt EP l Enter profile 1 1 15 Enter point 1 2 28 Point 2 3 37 Point 3 4 40 Point 4 5 37 Point 5 6 28 Point 6 T 15 Point 7 8 lt CR gt Type carriage return to end the profile gt The time betwe
71. ment with the product A typical example of this is a registration mark on a bag which is used to maintain position with respect to the printed pattern on the bag Page 52 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 12 2 Setting Up the Reference Position The reference input has already been set up see earlier When the PTS was initialised the datum point became the absolute zero position This also corresponds to the start and end of a cycle on a rotary machine As the cycle length is set by the bounds as shown earlier then the boundary between one cycle and the next should coincide with the datum point This is best shown with a number of examples Lug belt Proximity switch Bound Bound Encoder positions 0 gt 7500 gt 7500 Proximity switch i Cycle gt lt Cycle gt Using the previous example of a lug belt with three lugs the proximity detector used for initialisation is the datum The bounds in the example were set to the distance between successive lugs of 7500 counts which is equivalent to 1 index of the belt After each index the position returns to zero at the boundary and this should be coincident with the next lug aligning with the proximity detector It may not quite line up as it is difficult to manufacture a belt where the distance between the lugs is exactly uniform Auto referencing compares the position of the
72. n and they will terminate any command or sequence that is currently being executed In just the same way as the initialisation the rate of stopping with the command can be altered with the command as will be seen later Copyright 1995 Quin Systems Limited Page 15 PTS User s Guide Revision 2 3 4 2 Moving With the motor at absolute position zero it can now be moved to any position required The PTS can generate its own motion profile which will be either trapezoidal or triangular in shape depending on the distance moved Velocity Velocity Distance area under curve Set velocity Actual peak Di s istance velocity area under curve Time Time This is the basic method of moving the motor to position with the PTS The move command takes the form nn For a move to an absolute position relative to zero The parameter nn is an absolute position value between 0 and 4 000 000 nn For a move to a position relative to the current position The parameter nn is a relative position value between 0 and 8 000 000 For positive positions the sign can be omitted for simplicity if preferred Here are a few examples 4000 This command moves the motor to a position 4000 counts in the positive direction from the reference point 0 This command returns the motor to the reference point 332 This command moves the motor to a position 332 counts in the negative direction from the reference point D
73. n 255 on power up DBO For quick action on analogue error DW00100000 For absolute maps Channel 1 Parameters RH Spool CH1 AC850 AH1300 AI41 AL400 AO4 AP40000 CW01010000 DC40000 KP300 KV1300 KF1660 KMO OM325 MW00010000 SA40000 SB100000 SFI SS8000 SV5000 Channel 2 Parameters Print Cylinder CH2 AV4 CT64 CW01100000 DC20000 DZO KP300 KV1300 Copyright 1995 Quin Systems Limited Set point High limit Integral gain for tension loop Low limit To allow PEC sensitivity signal on CH4 Proportional gain for tension loop Positive direction clockwise For alignments Position loop proportional gain Position loop velocity feedback Position loop velocity feedforward Allows constant output signal fixed by OM Speed mapping For alignments Bound value not important To allow analogue output on ch4 For alignments For jogging To smooth MB change Ramp for startup Positive direction clockwise For alignments Marker pulse not required Position loop proportional gain Position loop velocity feedback Page 93 PTS User s Guide KF1660 MF5184 MW00010000 SA20000 SB10376 SS1000 SV5000 TO128 Channel 3 Parameters LH Spool CH3 AC850 AH1300 AL400 CW01010000 DC40000 KP300 KV1300 KF1660 MW00010000 SA40000 SB100000 SS8000 SV5000 Channel 4 Parameters CH4 CW01100000 SB40000 Channel 5 Parameters CH5
74. n be filtered out without compromising the accuracy of the position synchronisation 8 1 5 Tension Control This application makes use of the major tension control features Their implementation in this application will now be discussed Since the diameters of the unwind and rewind spools change as the paper is wound from one spool to the next the speed ratio between the spools must vary In order to keep the tension arm at a constant position as this ratio changes it is necessary to use integral gain in the tension loop No differential term is used in this application This is generally only required when the motors are poorly tuned and the use of a non zero differential term then prevents the motor reacting to its own position errors If servomotors are used and the inertias are well matched then the motor should be able to run and change speed with the minimum variation in following error As a follow on from the above point it is also important that the following error does not change significantly with motor speed If it did then the motor would lag behind as the machine ramps up and the tension loop proportional gain would then be required to re position the arm Velocity feed forward should be used in the position loop for the slave and the master if it is driven This position loop tuning must be done prior to attempting to tune the tension loop In an unwind rewind application where integral gain must be used it is also importa
75. ndex takes place Filling Pa Velocity cans 60 Full cans e Index Fill Index Fill Index Fill Index Indexing starwheel Time The delay command is or wait for time and has the following syntax n Wait for time n The time value n is in 1 256 second units about 4 ms This can now be inserted into a sequence to produce the indexing required The example shows just one complete revolution of the starwheel For continuous operation replace 3 with just RP System Command Comments gt MR3300 WT128 RP3 Index wait for 1 2 s and repeat 3 times M Index 1 WwW Waiting M Index 2 WwW Waiting M Index 3 WwW Waiting M Index 4 WwW Waiting gt End of cycle As you can now see just about any command can be put into a sequence Page 28 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 8 Sequences That Can Be Saved After experimenting with a number of sequences it is much more convenient to call them with a single command and to be able to combine sequences together to form more complex operations To enter a sequence to be called by a single command you enter privileged mode then use the enter sequence function n Enter Sequence number n Example 1 Enter sequence 1 The following example shows the starwheel sequence being entered for single command execution System Command Comments gt ES1 Enter sequence 1 S1 MA3300 WT128 RP3 The indexing sequence required
76. nds like the reference input definition DR must be specified on the respective channel The use of debounce should also be taken into account since the DB command applies equally to all inputs on one channel except not to DR and DS inputs Don t mix inputs which don t require debounce with inputs which do on the same channel 9 Declare variables in the autostart sequence Before a sequence is executed the PTS firmware will parse it to check it for obvious errors like the sequence calling itself for example If the sequence were to contain a statement SV SPD before SPD had been given a value then it would not be able to execute It is therefore good practice to declare variables in the autostart sequence by setting them to arbitrary values See sequence 255 in worked example 1 Variables which are defined as associated variables in the operator s panel can be initialised on startup by selecting this option in the attribute menu These variables don t then need to be declared in the autostart sequence 10 Define trigger variables in the autostart sequence not as saved parameters The definitions should be after each variable has been given its initial value further definitions cover any trigger variables which are operator s panel associated variables which are initialised on startup This is because when the PTS starts up variables which are initialised on startup in the operator s panel are written to with their saved values
77. nn encoder counts Example 900 This sets the allowable position following error to 900 counts The default value is 800 counts Copyright 1995 Quin Systems Limited Page 21 PTS User s Guide Revision 2 3 5 3 Timeout Error If during the move the error message T appears or the longer motor timeout followed by a prompt then the PTS is reporting that the encoder has stopped turning during a move and has switched the servo off motor off This occurs if the motor is stuck or if the motor or encoder is not functioning The main reason for having the timeout error condition as well as the position following error is so that if the set value has to be larger than is desirable because the mechanics make it hard to tune the PTS the timeout error can still be set to a small value to detect a jam in the mechanics The timeout value is set with the command n Set timeout value Set the maximum time allowable for the position to remain stationary during motion The value n is in units of 1 256 seconds about 4 ms Example 3 This sets the maximum time that the encoder is allowed to stop during a move to about 12 ms The default value is 32 about 125 ms Both the and values should be set as small as possible to maximise safety and minimise damage to product or machinery if something goes wrong In both cases when triggered the servo loop is switched off and also a voltage free contact is closed This
78. nt Page 94 Half bound value Bound value Constant speed for printing Sine squared for limp Sine squared for limp Constant speed for printing Map number Make sure map isn t being used Trigger map generator Copyright 1995 Quin Systems Limited Revision 2 Channel error sequence ES91 GF Channel 2 error sequence ES92 GF Channel 3 error sequence ES93 GF Tension error sequence ES99 CH1 DEA DA CH1 AYC AC PTS User s Guide Stop all motors Stop all motors Stop all motors Read DA value Read set point IF DEA gt A YC MSG 12 EL MSG 13 Display appropriate message Start Machine ES100 IF DIR 0 XS102 EL XS104 Determine correct direction Start machine Right to Left ES102 CH1 AW1xxxx1xx CH2 RFO CH3 SV MAX SPD 100 VC MSG 6 Correct sense of tension loop amp integral Initialises in R to L direction Start machine Machine running IF PRI 1 CH2 XM1 EL CH2 ST Map print drum on clutch if required Start machine Left to Right ES 104 CH1 AWOxxxx1xx CH2 RF945 CH3 S V MAX SPD 100 VC MSG 6 IF PRI 1 CH2 XM1 EL CH2 ST Stop Machine ES110 MSG 8 For correct sense of tension loop Compensates for size of target Start machine Machine running Runs CH2 on clutch if required Machine stopping IF PRI 0 XS111 EL XS112 Stop off print if printing cycle stop Stop
79. nt to disable the integral term when the master is stopped This is to prevent the arm stopping with a tension error which would then be integrated up by the integral gain term The effect of this would be to slowly change the SM while the machine was stopped in an attempt to correct the arm position Changing SM would not correct the arm position if the master is stopped and the net result would be an incorrect SM ratio when the master did in fact start up This integral term disabling is done in sequences 111 and 112 by clearing bit 2 in the analogue word Copyright 1995 Quin Systems Limited Page 89 PTS User s Guide Revision 2 The sense of the tension loop depends on the direction of web travel Bit 7 is therefore inverted when the direction of the master is reversed See sequence 102 and 104 In one direction the slave must drive faster for a given tension error In the other direction it must drive slower to correct the same tension error Bit 6 in the analogue word is not direction sensitive Once the control words have been fixed and for a given web wrap orientation on the spool clockwise or anticlockwise bit 6 can be fixed This application uses the automatic SM calculation routine by having bits 4 and 5 set in the analogue word prior to executing the map on the slave when the machine is initialised in sequence 200 The high and low limits AH and AL for the analogue signal must be set on both the master and slave channels if bot
80. nual covers the full range of PTS products which are divided into two groups Single axis Controller Only the first section of this manual applies to the single axis controller system This section also applies to individual channels of the multi axis systems o gt o o o o o o o e7 D o o o o o o o e7 D o o o o o 26 o ooooo 00000 cock oooo Multi axis MiniPTS PTS 4 PTS 12 All sections of the manual apply to these systems They allow separate although simultaneous control of motions as described in the first section They are also capable of synchronising a group or groups of motions to mimic a mechanical transmission in a machine Motions can be run in parallel on different motors or sequenced one after another m o MiniPTS O O KA O QUIN o O PTS 4 eo oO QUIN a PTS 12 Copyright 1995 Quin Systems Limited Page 5 PTS Users Guide Revision 2 3 Section A Single Axis Control 3 1 Scope of this section This section applies to the Single Axis Controller and to any individual axis of the multi axis PTS systems The prompts shown in this section refer to the single axis controller In the case of the multi axis systems the prompts are prefixed by the current channel number but are otherwise identical 3 2 Description of Single Axis Controller The Single Axis Cont
81. odels place this software in a separate processor linked through the high speed data link known as a bus Although this may seem more complicated it is in practice just the same to use as a single axis controller with extra commands to support the multi axis facilities 4 3 First Steps The same precautions of using guards and limit switches should be taken as described in Section A On power up the prompt should show one of the following 1 Servo loop inactive motor off on channel axis 1 1 gt Servo loop active position control on channel 1 Note that the prompt character is now preceded by the current channel number It is possible to put in your own Autostart sequence which can override the above if required It executes automatically when the system powers up This is described later in this section All the single channel functions described in section A can be implemented in the same way except that the channel number precedes all of the prompts returned by the PTS Page 58 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 4 4 Changing Channels It is possible to change to work with another channel at any time even if the channel you are currently on is in the middle of a motion Changing channel is achieved with the change channel command n Change working channel to n The channel number n ranges from 1 to a maximum of 48 depending on how many channels or axes are in the pa
82. on on how to do this It is good practice having high lighted the text in the PTSnote window and selected copy to click in the PTSnote window to de select the text This will prevent the text being replaced or deleted inadvertently if any other key is pressed instead The above copying and pasting method is useful when making changes to a specific sequence If a number of changes have been made throughout the program file it is more convenient to use the File Download facility This will download the complete program file from the PC to the PTS and overwrite any existing program in the PTS Make sure that the PTSnote file has been saved before downloading since the download option will download the disk file and not the text as shown in the PTSnote window Copyright 1995 Quin Systems Limited Page 81 PTS User s Guide Revision 2 7 8 Good Programming Techniques The following suggestions should be considered when writing programs for the PTS 1 Keep sequences short Although the PTS is happy to accept long sequences it is easier to write a program prove it out and track down programming problems if the sequences are kept short A sequence should be used for a specific function like Machine Start If there are a number of ways in which the machine could start then use a sequence for each possible start condition Worked example 1 shows that 3 sequences were used to start the machine 2 Keep the sequence numbers in ascending or
83. ondition such as a jam during the current operation Page 24 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 7 Single Line Sequences Up until now you have been entering one command at a time which is adequate for experimentation but does not cater for an automatic sequence of moves In the case of the lug belt for example the indexing needs to be continuously repeated in the forward direction without operator intervention A simple sequence to move forwards then backwards is shown below and just consists of the same commands as before put into a line or string of commands with separators or delimiters between each command Move forwards Velocity Move backwards Time System Command Comments gt MA12000 MAO Move fwd 12000 counts and return to zero M Moving forwards M Returning gt Arrived back at reference position In this case the separator is a character but other non alphanumeric characters can be used such as a full stop for example 3 7 1 Repeating Sequences As many motions are repetitive it is important to be able to create an automatic loop for repeating functions This is achieved by using the repeat command at the end of a line sequence n Repeat the current command line n times If the repeat count n is omitted the command line is repeated indefinitely 3 Repeat line 3 times RP RP 5 Repeat line 5 times RP Repeat indefinitely
84. onger motor position error followed by a prompt then the PTS is reporting that it cannot follow the move and it has switched the servo loop off motor off Assuming that the encoder is wired the correct way round as warned earlier the error could be for four main reasons The acceleration or velocity is too high for the motor to follow This is easy to remedy by lowering the acceleration and or velocity There is a fault with the motor drive or encoder This could be because the motor or drive is not on or enabled or the encoder may not be counting correctly This can diagnosed by using the command while in motor off Refer to the section in the Installation Manual on testing the encoder for more details The control loop tuning is incorrect Please refer to the section in the Installation Manual on tuning the motor for more details The mechanics are too stiff or heavy This is outside the parameters controllable by the PTS and requires some additional design work on the machine itself or a different choice of motor and drive to get sufficient power to drive the additional load 3 5 2 Position Following Error The position following error is triggered when the difference between the demand position and the actual position exceeds a preset value This value is set with the command nn Set maximum position error This command sets the maximum allowed difference between the demand and actual position to
85. or position while the fault is cleared Page 38 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 9 5 Listing Line Definitions Having now implemented a two way interface between a PLC and the PTS it is useful to display a summary of the current definitions of the 7 input and 7 output lines This is abhieved with the list input LO jist output line definitions commands List input line definitions The result is printed on the terminal System Command Comments gt LI List inputs command Inputs 1 R Reference input 2 ISOI IN CO1 Initialise 3 I XS1 SO1 WT3 CO3 Index 4 IST Stop 5 I PC MAO Restart 6 L Limit switch input active low T L Limit switch input active high List output line definitions Outputs 1 2 E Error output line a 4 5 6 T gt Even though output one is being used in one of the sequences as the ready signal to the PLC its status is not permanent and is therefore not shown on this display Copyright 1995 Quin Systems Limited Page 39 PTS User s Guide Revision 2 3 9 6 Reading Inputs In order to test the operation of the input connections or the PLC it is very useful to be able to read the current state of the input lines This is achieved with the read input command This command can be used in two ways either to read the state of a specific input line or to show the state of all inputs n Read input line
86. ormed on the tape The direction of the tape can be reversed and its speed and tension can adjusted in process The printing operation position synchronises to the motion of the tape and the print drum profile is calculated by the Mini PTS to suit the print length and pitch settings as specified in the Operator s Panel Print Drum Spool Encoder Ch Ch 4 S Wrap Some of the above PTS features will now be discussed 8 1 1 The Map Generator The Map Generator is an optional software module for either the Mini PTS or the PTS Its purpose is to calculate a position map from the values of specific PTS variables Refer to the instruction manual for the Map Generator for details on exactly how to use this software The software can only be used with the appropriate software key Sequence 10 in the worked example recalculates new values for the Map Generator variables prior to the map generation being triggered with the MTR 1 command at the end of the sequence The sequence uses PTS expressions to calculate new values for the master and slave variables M01 M02 M03 M04 S01 S03 These values are based on the values of the variables LEN REG ECM and PCM which are all specified through the Operator s Panel In this application ECM and PCM are variables whose values are set through the Operator s Panel They represent the encoder counts per mm and the printdrum counts per mm respectively Since these need to be specifi
87. ortant to make sure however that during the evaluation of a lengthy expression the intermediate result never exceeds 2 billion The values are held as signed 32 bit numbers and an overflow could occur In this case perform divisions before the end of the expression to keep the intermediate result within 2 billion 7 Don t write to a trigger variable in the same trigger variable s definition For example SPD gt SPD 1 Will force the trigger variable to execute continuously Page 84 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 8 Don t attempt to use the same digital input for more than one function by reassigning it It is possible to undefine a limit switch input for example and to redefine it as a defined input or vice versa However since the current input configuration cannot be tested it is possible for a program to attempt to undefine a limit input with a DI command if it has got out of step This will stop a sequence with an error If the same external signal has to be used for more than one function link the signal to two inputs and define each input to perform a specific function 9 The RM commands are not saved If referencing is required on a channel at some point then set RM to 1 in the starting sequence usually after successful IN or IB and use the reference word RW bit 0 to enable disable the reference correction 10 If maps are being written for the PTS choose the map step c
88. ows the amount of tension to be adjusted by varying the air pressure from a regulator 6 2 Tension Control using S wrap rollers This solution is similar to the dancing arm above in that an arm is rotated to measure the material tension Many of the points above apply equally well to an S wrap arrangement However it does have a number of advantages over a dancing arm Page 74 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide Mechanically the arm is balanced since it can be made to rotate about its centre of gravity It weight therefore is not relevant However its inertia still is Since an S wrap arm is generally more compact than a dancing arm its inertia is probably less than that of a dancing arm The angle of wrap of the material around the rollers is less This may be beneficial to some materials The arrangement is inherrently more rigid than a dancing arm which would need additional mass to provide better stiffness An S wrap arm does require 2 rollers which increases the number of mechanical parts The idler rollers can be positioned such that the arm movement is reasonably linear even in a compact space A linear arm provides a linear relationship between arm angle and tension An S wrap arm can be made to rotate through a greater angle than a dancing arm This minimises the need for potentiometer gearing or high voltages across the potentiometer 6 3 Tension Control using a Linear Roller This is rea
89. r these systems are preceded by the axis or channel number that is currently being programmed The multi axis PTS units otherwise can perform all the single axis functions described in section A 4 2 Description of the Multi axis Systems The range of QUIN multi axis Programmable Transmission Systems currently comprises the MiniPTS the PTS 4 and the PTS 12 the number denoting the maximum number of axis cards in a particular system The models come in 3 frame sizes o MiniPTS PTS 4 QUIN PTS 12 Copyright 1995 Quin Systems Limited Page 57 PTS User s Guide Revision 2 The frames are available to be either bolted to a flat vertical surface or as 19 rack mounting systems For more details please refer to the appropriate Installation Manual Internally these systems can be thought of as having multiple Single axis Control units inside one for each motion controlled or monitored The software structure is partitioned to operate individual control tasks for each axis with input and output lines allocated per axis each motion thus operates independently until synchronisation between motions or groups of motions is required The MiniPTS implements this multi axis software using one common processor the larger models use one processor per axis or per 4 axes The whole is synchronized by a host task which responds to user input and coordinates the axes the larger m
90. rigger variable MST is undefined before setting its value to 1 to prevent anything being triggered 8 1 2 The Operator s Panel This machine is operated entirely from an Operator s Panel There are no pushbuttons Associated variables in the Operator s Panel configuration are defined as trigger variables in the PTS program These trigger variables are not saved using the SP command Instead the trigger variables are defined when the autostart sequence 255 runs This is to prevent the trigger sequences running on start up because the associated variables are initialised on startup as part of the panel configuration See point 10 in the Good Programming Techniques section The Application Pack disk contains the operator s panel setup for this application TENRIGO2 PAN This can be downloaded to a PTS which has a software key to enable the Operator s Panel feature 8 1 3 Trigger Variables These are used to allow requests from the operator s panel from function keys and parameter adjustments from the display pages to make the relevant motion changes through the PTS program The commands following the trigger variables are both sequence executions and specific mnemonic commands 8 1 4 The Use of a Virtual Channel A virtual channel has many uses It can be used to simulate the presence of a motor for testing It can be used as a master channel to which a slave has been mapped thereby performing a single axis motion profile whose
91. roller controls a single servo motor via a 10 V velocity command signal connected to the motor s amplifier drive The position of the motor is fed back to the controller to provide closed loop control The position of the motor is measured in counts These are derived from pulses from the shaft encoder which are multiplied by four inside the controller Velocity is also obtained from the encoder pulses and measured in counts second Acceleration or change in velocity is controllable and is measured in counts second All commands described in the following section are entered from a terminal or an IBM PC or compatible machine running a communication program connected to the RS232 socket Please refer to the TRC Installation Manual for more details Motor encoder Motor Power L Drive Position Encoder Signal Controller Analogue Speed Control nputs Outputs Output PLC or Page 6 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 3 Setting Up the PTS 3 3 1 First Steps It is imperative to read the Installation Manual particularly the section on Guards and Limit Switches before you attempt to switch on any of the units Assuming the QUIN PTS is correctly connected to the motor drive encoder and terminal switch on power to the PTS NOTE All the commands used in this manual are highlighted by a box as
92. ror and limit switch error automatically turn the servo loop off and a voltage free relay contact on the PTS changes state This relay can be wired through to a brake or drive disable function if required If the PTS has found such a fault because for example a product has caused a jam the machine operator or PLC must be told so that it can take action before carrying on with another index The error reporting can be achieved by defining one of the output lines as the error function so each time a PTS error condition arises the output line will change level Example 2 Define error to set output 2 low 0 V 2 Define error to set output 2 high 24 V PLC PTS t ERROR Time Input B Output 2 lt Input C Operator Clear Output C gt Input 5 a Pedi PC Output B gt Input 3 7 If line 2 is wired to a PLC and it receives the error signal the PLC may want to take some actions of its own When these are completed the PLC could wait for the machine operator to press a button then issue a command to the PTS to return to the beginning of the cycle The process can then carry on as before with the index being triggered from input 3 A suitable sequence may look like this DI5 PC MAO0 Input 5 turns servo loop back on then moves the motor to the zero position This will only work if the controller and encoder power supplies are not switched off when the fault was detected so that it can keep track of the mot
93. rticular system you are working with Example System Command Comments 1 gt Channel 1 prompt 1 gt CH2 Change to channel 2 2 Prompt for channel 2 2 PC Turn on position control on channel 2 2 gt Copyright 1995 Quin Systems Limited Page 59 PTS User s Guide Revision 2 4 5 Simultaneous Motion The functions available on channel 2 are identical with those of channel 1 and can be entered in the same way even if motor is still running Motor 2 can now be set running in a completely different mode of operation to Motor 1 and then if there is a third channel in your system this too can be set in operation simultaneously Example System Command Comments 1 gt MA10000 MAO RP Set motor 1 to reciprocate 1M CH2 Switch to motor 2 leaving motor running 2 gt SV20000 VC Run motor 2 in velocity control mode 2V CH3 Switch to motor 3 leaving and 2 running 3 gt XP2 XS3 Run profile 2 and sequence 3 on motor 3 3P Executing profile 2 3M Executing sequence 3 as an example 3W 3M 3 gt ST Stop motor3 3 gt CH1 Switch to channel 1 1M Motor still moving 1M ST Stop motor 1 1S Motor 1 stopping 1 gt CH2 Switch to channel 2 2V Motor 2 still moving 2V ST Stop motor 2 2 gt There are many possibilities of motion on all the different axes due to the flexibility of the PTS parallel processing capability The next subject to be covered can form the basis of many high speed machines This is the Software Gearbox the hear
94. splayed on the terminal Once a limit switch is activated the mechanics must be physically moved away from the switch in order to proceed Page 8 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide 3 3 4 Servo Loop The terminal should now show a prompt of either of the following This means the servo loop is open motor off PTS Drive Motor g a 5 T Position is measured Encoder gt This means the servo loop is closed position control PTS Drive Motor AN 10 V command RE i e GD Position is controlled Encoder Both of these are valid and merely indicate the status of the unit To proceed you need to be in position control mode This is achieved by typing in the following This will ensure that the servo loop is active and the controller is in position control mode The prompt should now be the gt character If it returns to a motor off prompt or the motor accelerates rapidly to maximum speed in one direction then it is likely that the encoder is wired the wrong way round and should be reversed Please refer to the PTS Installation Manual for more details Now that the controller is in position control mode the closed loop is active and the loop can be tuned for the particular motor drive and mechanics connected refer to the PTS Installation Manual This must be done before proceeding
95. ssary to enter the first and last points Entering a map is rather like entering a profile as described in section A After executing the n or enter map number n command you will be prompted by the system with the first master position Type in the equivalent required slave position Copyright 1995 Quin Systems Limited Page 65 PTS User s Guide Revision 2 The next prompt will be the next position along the master axis as defined by the map step command Example System Command Comments 2 gt EM 1 Enter map 1 M1 0 First master Position 0 Enter first slave position M1 4000 Next master position 8000 Enter required slave position M1 8000 Next master position lt CR gt Type carriage return to end map entry 2 gt This example enters a 4000 point map defining a 2 1 ratio between channel 2 and an as yet unspecified master channel There may be a pause of up to a few seconds between entry while the PTS calculates the intermediate points between the position increments entered 5 3 3 Link the Slave to the Master Having now created a map for the slave channel 2 the slave must be informed which other channel is the master This is done with the map link command n Map link to channel n This links the current channel to the specified master channel n The command must be entered on the slave channel Example System Command Comments 2 gt ML 1 Link this channel 2 to channel 1 as a master 2 gt
96. st line prevents the second line from executing if the first line has already executed Copyright 1995 Quin Systems Limited Page 85 PTS User s Guide Revision 2 8 Discussion of Worked Examples One of the best ways of learning is by example The remaining section of this guide provides a discussion of worked examples For each example there is an introduction to the application followed by an explanation of how and why the PTS program has been written 8 1 Worked Example 1 This example discusses the following PTS features the map generator the operator s panel the use of trigger variables position mapping speed mapping the use of a virtual channel tension control referencing error handling the use of variables and expressions conditional program flow defined inputs logical operations message handling The above features were required in order to control the motions and provide the operations of a printing machine which also included the control of unwinding and rewinding spools containing the print web A Mini PTS was used for the application Page 86 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide The figure shows a layout of the machine Each major component of the machine is identified in the drawing The machine unwinds paper tape from one spool and rewinds it under controlled tension on to the other spool During this operation printing can be perf
97. t of the Programmable Transmission System Page 60 Copyright 1995 Quin Systems Limited Revision 2 PTS Users Guide 5 The Programmable Transmission System The Programmable Transmission System is the technique of being able to synchronise a group or several groups of motions together to form a machine transmission system By driving the final motions as directly as possible each with its own servo motor a very accurate low inertia high speed transmission can be achieved with the ability to change the motion profiles to suit different requirements of the machine 5 1 Software Gearbox The Software Gearbox can be described in much the same way as a mechanical gearbox A typical mechanical transmission may comprise a set of gears as shown Slope gear ratio Slave Slave position Master Master position In a gearbox one gear is driven by an input shaft and one or a number of the other gears are attached to output shafts The input gear will be referred to as the master and any output gear in mesh will be referred to as a slave In a gearbox the gear ratio is proportional to the number of teeth on the master gear compared to the number of teeth on the slave The teeth normally being the same size the ratio is also proportional to the relative diameters or circumferences of the two gears Copyright 1995 Quin Systems Limited Page 61 PTS User s Guide Revision 2 With a belt transmission then the ratio of input to
98. tem Command 2 gt 2 gt 1 1 gt 2 gt 2 gt 2 gt 2M 2X UL CH 1 SB 300 CH2 SB 900 ML 1 XM 2 PTS User s Guide Comments Unlink channel 2 from the master Switch to channel 1 master Change the master bounds Switch to channel 2 slave Change the slave bounds Re link channel 2 to channel 1 Execute new map Executing new map Copyright 1995 Quin Systems Limited Page 71 PTS User s Guide Revision 2 5 6 Software Line Shaft A line shaft between machines can be easily copied by the PTS Instead of the master channel controlling a motor it can be connected to just an encoder perhaps mounted on a remote machine By setting the master channel to motor off and then linking the slave in the normal way the slave will now be synchronised to the remote encoder as though there was a line shaft between the two machines Turning the encoder on the master channel will cause the slave to follow according to the map executing on the slave As 1 1 maps are often used particularly to replace line shafts between machines this has been made a special case called map zero Map zero is a predefined map for a ratio of 1 1 between master and slave It is executed just like any other map but does not need to be defined by the user In this example channel 1 is the SLAVE and channel 2 the MASTER System Command Comments 1 gt ML 2 Map link channel 1 slave to channel 2 master 1 gt XM 0 Execute map zero a 1 1 m
99. the arm pivot shaft to the potentiometer such that the potentiometer moves through a greater angle for a given anagle of movement of the dancing arm This may eliminate the need for a larger voltage source but does introduce the possibility for backlash in its drive A potentiometer should ideally allow complete rotation of its shaft without any mechanical stops This allows the potentiometer to be set up without worrying about its end stops being broken if incorrectly adjusted The type of potentiometer track should be chosen to provide long life Plastic tracks have been used in a number of applications The mass of the dancing arm is important If the arm is stationary then its position reflects the tension in the material If the arm is accelerating then there is an additional tension in the material which is required in order to accelerate the arm This leads to an inaccurate tension measurement if the arm mass inertia is too high Counterbalance weights can only increase this effect and are therefore not a preferred solution The choice of roller diameter again has an influence on the arm inertia A minimum diameter may be called for since the product may be damaged if bent through a tight radius Too small a diameter will result in the roller having to run fast which may exceed its bearing capabilities Some mechanical damping has been found to improve overall tension control An air spring automatically provides this damping and also all
100. the print characters are at bottom dead centre The map is generated such that it is symmetrical and starts at a point half way through the printing The positioning of the reference proximity and the shape of the map forces an MF value to be set which is equal to half the bounds Page 90 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide As well as defining the zero position for the print characters on the print drum the reference proximity also serves another function The motor produces 4096 encoder counts per revolution There is a gear reduction provided by a single timing belt of 76 30 This results in 10376 5333 encoder counts per revolution of the print drum A non integer value for a cycle length is typical in applications Since a bound value can only be set to an integer value a bound value of 10376 counts without referencing would result in a drift of 0 5333 counts per cycle The use of referencing prevents this drift The target for the print drum proximity is approximately 5mm long The signal from the proximity therefore comes in at a different point in the cycle depending on which direction the machine is run In order to compensate for this a reference offset is applied to this channel when the machine is reversed See sequence 104 8 1 7 Error Handling The Mini PTS handles tension errors by using the analogue error output AE as described above The first line in sequence 201 tests the status variabl
101. uilt in features which are available with the PTS and not to attempt to program a facility which is in fact already present If the user is capable of writing programs in high level languages and has a full understanding of motion control then it can be tempting to try and construct a Quin Application program using PTS variables for example instead of using the existing mnemonic commands This should be avoided since the mnemonic command set within the PTS provides a collection of debugged and flexible routines which have been developed to provide solutions to the majority of motion control applications over a number of years Using the built in commands keeps the application program more compact and allows it to be understood more clearly by others who were not involved in its writing The programming examples in this guide all follow the same format Although this need not be rigidly adhered to when developing an application it has become a defacto standard and as such a format file NEW PTS is included on the application disk available for use with this manual This file provides the basic structure for the layout of anew program and includes headings for all the various sections within the program Copyright 1995 Quin Systems Limited Page 77 PTS User s Guide Revision 2 7 2 Filename Conventions The following filename convention should be used in order to identify particular filetypes on the PC PTS A textfile containing a commented
102. uring the move the prompt on the screen changes from a gt to an M When the move is complete the prompt returns to a gt character The change in prompt feature is used throughout to indicate the current status of the PTS Page 16 Copyright 1995 Quin Systems Limited Revision 2 PTS User s Guide Another type of move that is useful is the relative move Instead of moving to an absolute position you can move a set increment relative to the current motor position 500 This command moves the motor 500 counts from the current position 200 This command moves the motor 200 counts backwards from the current position With the commands learnt so far it is possible to put in a series of commands to move forwards backwards and stop System Command Comments PC Position Control Switch on the servo loop Servo loop on ID Initialise Offset Correct for drive offset IN Initialise Position Move to reference position Initialising At reference position MA10000 Move Absolute Move to position 10 000 counts Moving Move completed MR600 Move relative Move a further 600 counts Moving Move completed MAO Move Absolute Return to the reference position Moving ST Stop Decelerate to a stop Stopping Stopped VnZEZevVVEVV EVV TV VV Copyright 1995 Quin Systems Limited Page 17 PTS User s Guide Revision 2 3 4 3 Acceleration and Velocity All the previous move profiles have been calculated using the default accelerat
103. ve may need to be switched on just prior to the can arriving underneath and inhibited from inadvertent operation during indexing This used to be accomplished with a cam switch just like you might find inside a washing machine except geared to the starwheel motion The PTS has the very powerful facility of being able to mimic up to 7 individual cam switches related to the position of the encoder This function is called position trigger and uses the command A high or low electrical pulse can be created on any of the 7 output lines and the switching of the pulse can be accurately aligned to an absolute position in a cycle In the starwheel example the filler may need to be switched on at position 3000 counts for the first index and off again at 3320 counts Soe ee I CR Position zero Position 3000 Position 3300 Position 3320 Output line 0 3000 3320 This all sounds reasonable except that only one pulse can be generated per cycle of the machine on each output line The previous setup having the bounds set to four index cycles would require four separate output lines to give four position trigger outputs through the complete machine cycle As the cycle is exactly the same for every index 1 4 turn there really is no need to define the cycle for a complete revolution but only over one single index NOTE Whenever a cycle length is defined for any machine always try and define it over the smallest su
104. y NOTE If the previous definitions are now saved then every time the PTS is switched on input 2 starts the initialise function and input 3 starts the index cycle The definitions are saved with the command as used before NOTE Each time that inputs 2 and 3 are redefined the previous definition is replaced This is why the command is restricted and can only be used in privileged mode to prevent accidental deletion of an existing input line definition As the last two definitions have not yet been saved with the command you can recall the previous definitions with the read data command If you try to define an input line which is already used for a different input function the U error message is returned 3 9 3 Defining a Stop Input It may be necessary to stop the motion in case of a fault condition This can be done simply by triggering the stop command from another input say input 4 Example 4 Define input 4 to stop the motion The PLC can now initialise and start the motion just by switching outputs and it can detect that the motion is complete by scanning an input line If necessary it can also stop the motion at any time with another output signal Copyright 1995 Quin Systems Limited Page 37 PTS User s Guide Revision 2 3 9 4 Error Reporting The PTS as discussed already can detect most machine faults on its own and shut down the motion The position following error timeout er

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