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1. 14 11 G40 G41 G42 Cutter Radius Compensation To turn cutter radius compensation off program G40 It is OK to turn compensation off when it is already off Cutter radius compensation may be performed only if the XY plane is active To turn cutter radius compensation on left i e the cutter stays to the left of the programmed path when the tool radius is positive program G41 D To turn cutter radius compensation on right i e the cutter stays to the right of the programmed path when the tool radius is positive program G42 D The D word is optional if there is no D word the radius of the tool currently in the spindle will be used If used the D number should normally be the slot number of the tool in the spindle although this is not required It is OK for the D number to be zero a radius value of zero will be used It is an error if CHAPTER 14 G CODES 141 e the D number is not an integer is negative or is larger than the number of carousel slots e the XY plane is not active e or cutter radius compensation is commanded to turn on when it is already on The behavior of the machining center when cutter radius compensation is on is described in Chapter 2 14 12 G43 G49 Tool Length Offsets To use a tool length offset program G43 H where the H number is the desired index in the tool table It is expected that all entries in this table will be positive The H number should be but does not have to b
2. 1334 Unary Operation Value sc so soe sa ka caca ka A a ee 13 4 Parameter Seting 022 0 SRR RP a a aaa aa 13 5 Comments and Messages 0 06 aoa d oea ara aaea dokaa a a aaae i w E a 138 Repeated Memes 4 5 a A a AS dt a a a da 137 Tiemi order ad A e aa E A a ee RADA A As 13 8 Commands and Machine Modes 139 Modal Groups se sas rsca ee adaa da E aea Ea a i de a e 14 G Codes 14 1 GO Rapid Linear Motion o o sa ce ace ee PA a a we ee Se ee 14 2 1 Linear Motion at Peed Rate lt s ek eee ee we wee ee 143 G2 G3 Arcat Fed IE 1431 R dius format arts ic cer A le a a 14 52 CONDS forint ares eo eaea A ee Bea a el we e a e 14 4 G33 Spindle Synchronized Motion 14 5 GE DWE ck eat e A A A AEE e de e ES 14 6 G10 Set Coordinate System Data 14 7 BIZ GIS GIS Plane Selecon oe we ma Ow a e ae a 145 C20 o Length Units lt lt ee Re Dee eee e a ee 14 9 G28 G30 Return to Predefined Absolute Position o T4 I0 G30 A ee Probe idle i Reo ke Siow lee Midi a HOLE Dl ah ae de wl A a 14 11 G40 G41 G42 Cutter Radius Compensation 14 12 G43 G49 Tool Length Offsets 14 13 G53 Move in absolute coordinates ee ee 2 14 14 G54 to G59 3 Select Coordinate System 6 ee 14 15 G61 G61 1 G64 Set Path Control Mode 14 16 G80 Cancel Modal Motion ses ew ee ee a 14 17 G76 Threading Canned Cycle occiso csi REEDS e
3. 1 1 1 SH 2 1 CUT 3 0002 SCALE F999 GOO 21 GOO X 1688 00 3 842 00 3 ON No tool Figure 1 2 The AXIS Graphical Interface Tkemc and Mini will run on Linux Mac and Microsoft Windows if the Tcl Tk programming language has been installed The Mac and Microsoft Windows version can connect to a real time EMC2 running on a Linux machine via a network connection allowing the monitoring of the machine from a remote location Instructions for installing and configuring the connection between a Mac or Microsoft Machine and a PC running the EMC2 can be found in the Integrators Handbook 1 5 2 Motion Controller EMCMOT Motion control includes sampling the position of the axes to be controlled computing the next point on the trajectory interpolating between these trajectory points and computing an output to the motors For servo systems the output is based on a PID compensation algorithm For stepper systems the calculations run open loop and pulses are sent to the steppers based on whether their accumulated position is more than a pulse away from their commanded position The motion controller includes programmable software limits and interfaces to hardware limit and home switches The motion controller is written to be fairly generic Initialization files with the same syntax as Microsoft Windows INI files are used to configure parameters such as number and type of axes e g linear or rotary scale factors b
4. dio lt dio string gt model lt model gt The base address field is optional if it s not provided the driver attempts to autodetect the board The num_chan field is used to specify the number of channels available on the card if not used the 8 axis version is assumed The digital inputs outputs configuration is determined by a config string passed to insmod when loading the module The format consists of a four character string that sets the direction of each group of pins Each character of the direction string is either I or O The first character sets the direction of port A Port A DIO O 7 the next sets port B Port B DIO 8 15 the next sets port C Port C DIO 16 23 and the fourth sets port D Port D DIO 24 31 The model field can be used in case the driver doesn t autodetect the right card version For example emc2 halcmd loadrt hal_stg base 0x300 num _chan 4 dio IOIO This example installs the stg driver for a card found at the base address of 0x300 4 channels of encoder feedback DAC s and ADC s along with 32 bits of I O configured like this the first 8 Port A configured as Input the next 8 Port B configured as Output the next 8 Port C configured as Input and the last 8 Port D configured as Output emc2 halcmd loadrt hal_stg This example installs the driver and attempts to autodetect the board address and board model it installs 8 axes by default along with a standard I O setup Port A
5. o 8 6 1 so INEA 8 6 2 PRG A E a we tes 8 6 3 Pome SESE EEE ES RE OSES GREER EES EE 8 6 4 PUnCHONS sor Gin A AAA a ew ls ae a 8 7 Pico Systems PPMC Parallel Port Motion Control Belal is o AE a oa OM eS i GE Ee amp A 8 7 2 PW AI E a o be 8 7 3 Paramete 2 0405 bb 8 Ra Eaa p aa we aa ee ee a 8 7 4 PUTMCTIONS caca a e e a RA A He De Wi ei ks a ww Ill Using EMC2 9 Using the AXIS Graphical Interface 9 1 Introduction 382 Getting Sted o oe see et Oa i RR ER RR we Ee a a ee ee 9 2 1 A typical session with AXIS os se cao satas daa A eee a da Elements of the AXIS window cosmo peia musaman nkau emeten 9 3 1 Toolbar DONONS A 9 3 2 Graphical Program Display Area 9 3 2 1 9 3 2 2 9 3 2 3 Coordinate DISP SF s ea or oona ei ee A a Ee i we ee a Pro ON PIN IA AE a a Ge A 4 a de Program DAVIS sso sosa o a RE ae vi 79 79 79 80 80 80 81 81 81 82 82 83 83 83 84 85 85 86 86 87 87 87 88 88 88 89 90 CONTENTS vii 43 21 Tol Ce o e i a ae A A AA a A a a 94 0 2 Packplot o ee Pa a e eas 94 9 3 2 6 Interacting with the display caco cassero esea mestes us 94 9 3 3 Text Program Display Area so o saoo ee as 94 9 3 4 Manual Control sp cocoa moia AAA oD we al A 95 93 41 The Bas group oo a a Ea Ne aa 95 9312 The Spindle SEOUP rec res kaca Sd de a a a a a a a 96 9 3 4 3 The Coolant Group si soc os e ss to saa a aa a ee
6. e BIT motenc lt board gt enc lt channel gt latch index If this pin is true the driver will reset the counter on the next index pulse e BIT motenc lt board gt enc lt channel gt reset count If this pin is true the counter will immediately be reset to zero and the pin will be cleared e FLOAT motenc lt board gt dac lt channel gt value Analog output value for DAC in user units see gain and offset e FLOAT motenc lt board gt adc lt channel gt value Analog input value read by ADC in user units see gain and offset e BIT motenc lt board gt in lt channel gt State of digital input pin see canonical digital input e BIT motenc lt board gt in lt channel gt not Inverted state of digital input pin see canonical digital input e BIT motenc lt board gt out lt channel gt Value to be written to digital output seen canonical digital output e BIT motenc lt board gt estop in Dedicated estop input more details needed e BIT motenc lt board gt estop in not Inverted state of dedicated estop input e BIT motenc lt board gt watchdog reset Bidirectional Set TRUE to reset watchdog once is automatically cleared CHAPTER 8 HARDWARE DRIVERS 87 8 6 3 Parameters e FLOAT motenc lt board gt enc lt channel gt scale The number of counts user unit to convert from counts to units e FLOAT motenc l
7. To add a simple external button you need to replace the line linkpp iocontrol 0 user enable out iocontrol 0 emc enable in with linkpp parport 0 pin 01 in iocontrol 0 emc enable in This assumes an ESTOP switch connected to pin 01 on the parport As long as the switch will stay pushed EMC2 will be in the ESTOP state When the external button gets released EMC2 will imediately switch to the ESTOP RESET state and all you need to do is switch to Machine On and you ll be able to continue your work with EMC2 4An extensive explanation of hooking up ESTOP circuitry is explained in the wiki linuxcnc org and in the Integrator Manual 5make sure you use a maintained switch for ESTOP Chapter 5 INI Configuration 5 1 Files Used for Configuration The EMC is configured with human readable text files All of these files can be read and edited in any of the common text file editors available with most any Linux distribution You ll need to be a bit careful when you edit these files Some mistakes will cause the startup to fail These files are read whenever the software starts up Some of them are read repeatedly while the CNC is running Configuration files include INI The ini file overrides defaults that are compiled into the EMC code It also provides sections that are read directly by the Hardware Abstraction Layer HAL The hal files start up process modules and provide linkages between EMC signals and specific hardware pins VAR The
8. 2 A pause for the spindle to reach index position 3 A spindle synchronized Z feed along the thread 4 A traverse to the original X 5 On all passes but the last a traverse Z move to the beginning point for the next pass The tool will pause briefly before each threading pass so a relief groove will be required at the entry unless the beginning of the thread is past the end of the material The exit move traverse to original X is not synchronized to the spindle speed With a slow spindle the exit move might take only a small fraction of a revolution If the spindle speed is increased after several passes are complete subsequent exit moves will require a larger portion of a revolution resulting in a very heavy cut during the exit move This can be avoided by providing a relief groove at the exit or by not changing the spindle speed while threading The sample program g76 ngc shows the use of the G76 canned cycle and can be previewed and executed on any machine using the sim lathe ini configuration Figure 14 1 G76 canned cycle Q 4 Final Pass l E First Pass i I A e Ne alan Drive Line Q Z Initial Point Tool Motions Thread Dimensions 14 18 G81 to G89 Canned Cycles The canned cycles G81 through G89 have been implemented as described in this section Two examples are given with the description of G81 below All canned cycles are performed with respect to the currently selected
9. Manual Data Input also called MDI allows G code programs to be entered manually one line at a time When the machine is not turned on and not set to MDI mode the code entry controls are unavailable Figure 10 4 The Code Entry tab G1 G17 G40 G21 G90 G94 G54 G49 G99 G64 G51 M2 M5 M9 M48 F225 51600 10 3 6 1 MDI This allows you to enter a g code command to be executed Execute the command by pressing Enter 10 3 6 2 Active G Codes This shows the modal codes that are active in the interpreter For instance G54 indicates that the G54 offset is applied to all coordinates that are entered CHAPTER 10 USING THE TKEMC GRAPHICAL INTERFACE 109 10 3 7 Jog Speed By moving this slider the speed of jogs can be modified The numbers above refer to axis units second The text box with the number is clickable Once clicked a popup window will appear allowing for a number to be entered 10 3 8 Feed Override By moving this slider the programmed feed rate can be modified Forinstance ifa program requests F60 and the slider is set to 120 then the resulting feed rate will be 72 The text box with the number is clickable Once clicked a popup window will appear allowing for a number to be entered 10 3 9 Spindle speed Override The spindle speed override slider works exactly like the feed override slider but it controls to the spindle speed If a program requested S500 spindle speed 500 RPM and the slider i
10. N6931 M9 10 2 Getting Started To select TKEMC as the front end for emc2 edit the ini file In the section DISPLAY change the DISPLAY line to read 104 CHAPTER 10 USING THE TKEMC GRAPHICAL INTERFACE 105 DISPLAY tkemc Then start emc2 and select that ini file The sample configuration sim tkemc ini is already configured to use TkEMC as its front end When you start emc2 with TKEMC a window like the one in Figure 10 1 is shown 10 2 1 A typical session with TkEMC 1 Start emc and select a configuration file Clear the E STOP condition and turn the machine on by pressing F1 then F2 Home each axis Load the file to be milled Put the stock to be milled on the table DOM ON Set the proper offsets for each axis by jogging and either homing again or richt clicking an axis name and entering an offset value N Run the program 8 To mill the same file again return to step 6 To mill a different file return to step 4 When you re done exit emc2 10 3 Elements of the TKEMC window The TKEMC window contains the following elements e A menubar that allows you to perform various actions e A set of buttons that allow you to change the current working mode start stop spindle and other relevant I O e Status bar for various offset related displays e Coordinate display area e A set of sliders which control Jogging speed Feed Override and Spindle speed Override
11. On the other hand if G92 values existed in the VAR file when the EMC started up Starting the EMC with g92 values in the var file is that it will apply the values to current location of each axis If this is home position and home position is set as machine zero everything will be correct Once home has been established using real machine switches or moving each axis to a known home position and issuing an axis home command g92 commands and values work as advertised These tests did not study the effect of re reading the var file while they contain numbers This could cause problems if g92 offsets had been removed with g92 1 but the var file still contained the previous numbers It is this complexity that causes us to say that G92 values must be treated as temporary They should be used to set global short term offsets The G54 59 3 coordinate systems should be used whenever long lasting and predictable offsets are needed 21 5 Sample Program Using Offsets This sample engraving project mills a set of four 1 radius circles in roughly a star shape around a center circle We can setup the individual circle pattern like this G10 L2 P1 x0 yO ZO ensure that g54 is set to machine zero gO x 1 yO zO gl fl z 25 g3 x 1 yOi 1 jo gO zO m2 CHAPTER 21 COORDINATE SYSTEM AND G92 OFFSETS 176 We can issue a set of commands to create offsets for the four other circles like this G10 L2 P2 x0 5 offsets g55 x value by 0 5 inch G10 L2 P3
12. POSITION_FILE position txt If set to a non empty value the joint positions are stored between runs in this file This allows the machine to start with the same coordinates it had on shutdown If unset joint positions are not stored and will begin at O each time emc is started 5 3 7 AXIS lt num gt Section The AXIS_0 AXIS_1 etc sections contains general parameters for the individual components in the axis control module The axis section names begin numbering at O and run through the number of axes specified in the TRAJ AXES entry minus 1 Values for the various parameters of LINEAR axes are in the units specified in the TRAJ LINEAR_UNITS entry Values for the position of ANGULAR axes are in the units specified in the TRAJ ANGULAR_UNITS entry TYPE LINEAR The type of axes either LINEAR or ANGULAR MAX_VELOCITY 1 2 Per axis maximum velocity while coordinated motion is in effect MAX ACCELERATION 20 0 Per axis maximum acceleration while coordinated motion is in effect 5This assumes there was no movement of the machine while powered off It helps on smaller machines without home switches CHAPTER 5 INI CONFIGURATION 33 BACKLASH 0 000 Backlash compensation value can be used to make up for small deficiencies in the hardware used to drive an axis Don t expect this to compensate for poor mechanical elements The value set here is in UNITS COMP_FILE file extension A file holding a compensation struc
13. Spindle 96 106 108 123 194 Spindle Speed Control 27 Spindle Speed Override 98 105 123 standard pinout 24 Step 107 Step Rate 23 stepgen 46 stepper 23 Stepper Motor 194 sub 153 supply 46 TASK 29 TBL 12 28 Tel 104 Tk 91 104 tkemc 5 29 104 Tool Carousel 123 Tool Changer 123 Touch Off 92 TRAJ 29 TRAJ PERIOD 31 Ubuntu 3 14 UNITS 34 Units 12 125 202 units 6 VAR 12 28 Verify 107 while 154 xemc 5 yemc 5
14. V2 1 User Handbook March 17 2007 The EMC Team This handbook is a work in progress If you are able to help with writing editing or graphic preparation please contact any member of the writing team or join and send an email to emc users lists sourceforge net Copyright c 2000 6 LinuxCNC org Permission is granted to copy distribute and or modify this document under the terms of the GNU Free Documentation License Version 1 1 or any later version published by the Free Software Foundation with no Invariant Sections no Front Cover Texts and one Back Cover Text This EMC Handbook is the product of several authors writing for linuxCNC org As you find it to be of value in your work we invite you to contribute to its revision and growth A copy of the license is included in the section entitled GNU Free Documentation License If you do not find the license you may order a copy from Free Software Foundation Inc 59 Temple Place Suite 330 Boston MA 02111 1307 Contents I Introduction amp installing EMC2 1 The Enhanced Machine Control 1 1 1 2 1 3 1 4 1 5 1 6 1 7 ENO aca a is E See e Seo a de Arse Ge dt Eee a The Big CNG PICS 3000 e a ee E E a id dei we e Computer Operating Systems 2 66 ee e si History of the SOTONITE cae cd a da EE ee ae ed ew a How the EMC Works os s coa aoi eet Bae eR eR RARER a a ae ee 1 5 1 Graphical User Interiates oe oo coe tora a ee 1 52 Motion Controller EMCMOT a seos em
15. which allow you to increase or decrease those settings e Manual data input text box e Status bar display with active G codes M codes F and S words e Interpreter related buttons e A text display area that shows the G code source of the loaded file CHAPTER 10 USING THE TKEMC GRAPHICAL INTERFACE 106 10 3 1 Main buttons From left to right the buttons are Eu Machine enable ESTOP ESTOP RESET ON Toggle mist Decrease spindle speed Set spindle direction SPINDLE OFF SPINDLE FORWARD SPINDLE REVERSE Increase spindle speed QO a A WwW N Abort then on the second line 1 Operation mode MANUAL MDI AUTO 2 Toggle flood 3 Toggle spindle brake control 10 3 2 Offset display status bar The Offset display status bar displays the currently selected tool selected with Txx M6 the tool length offset if active and the work offsets set by right clicking the coordinates 10 3 3 Coordinate Display Area The main part of the display shows the current position of the tool The colour of the position readout depends on the state of the axis If the axis is unhomed the axis will be displayed in yellow letters Once homed it will be displayed in green letters If there is an error with the current axis TKEMC will use red letter to show that for example if an hardware limit switch is tripped To properly interpret these numbers refer to the
16. 44 44 45 46 46 46 47 47 47 47 47 48 49 50 50 CONTENTS Vv Paid Examining the HAL oea a A A AA ee Ow LR a 53 LI Making realtime code TUT coccion a a ee e ee 55 7 3 4 Changing POoramelds i ke eh a ee Re are bh Oe wae 56 ton Saving the HAL configuration e 00 0 eee eee 56 7 3 6 Restoring the HAL configuration 2 2 666 ee ee ee Dee 57 7 4 Looking at the HAL with halmeter 57 7 4 1 e o s hee ac da ae Bee A a a Sc a ew He 57 7 4 2 Usime alme occ oo aa a A a ea ee A 59 7 5 Aslightiy more complex example s s 22 26 a ee Rae eR ww ee ae a 60 7 5 1 Installing the COMPponents s se com acma 1 ds ee e a 60 7 95 2 Connecting pins with signals gt s s cs cocer ee ee 61 7 5 3 Setting up realtime execution threads and functions sssaaa eaea 62 7 5 4 Setting PATAMETEES seco uri A we 64 7 5 5 AP a a a ee a Ve eee a 64 7 6 Taking a closer look with halscope 2 02 2 46440 2 HA BR we we ee 64 7 6 1 Sharing HSISCODE 0 cosida we Se aa a ee a 64 7 6 2 Hooking up the scope probes crear a REE a ee 67 7 635 Capturing our first waveforms 2 2 2 e 68 7 6 4 Vertical Adjustments 662 ad ceed ee ha AKER EDD ek hea a 69 7 6 5 TURCA sco ks Ghee ap KOM a De BOM a a a a a A 69 7 6 6 Horizontal AQTUSOMENTS o eoc ee we ee ee ee we 71 7 6 7 ta es ee a Nw eo a RR aw go eis BEE eed ee Be Ge 72 8 Hardware Drivers 74 Mok FaPO s e bate a Shad SE ae ae a a ae ee ae ee a we ee
17. G42 Tool Length Offset G43 G49 Return Mode in Canned Cycles G98 G99 Coordinate System Selection G54 G55 G56 G57 G58 G59 G59 1 G59 2 G59 3 Stopping MO M1 M2 M30 M60 Tool Change M6 Spindle Turning M3 M4 M5 Coolant M7 M8 M9 Special case M7 and M8 may be active at the same time Override Switches M48 M49 Flow Control O Non modal codes Group 0 G4 G10 G28 G30 G53 G92 G92 1 G92 2 G92 3 M100 to M199 For several modal groups when a machining center is ready to accept commands one member of the group must be in effect There are default settings for these modal groups When the machining center is turned on or otherwise re initialized the default values are automatically in effect Group 1 the first group on the table is a group of G codes for motion One of these is always in effect That one is called the current motion mode It is an error to put a G code from group 1 and a G code from group O on the same line if both of them use axis words If an axis word using G code from group 1 is implicitly in effect on a line by having been activated on an earlier line and a group O G code that uses axis words appears on the line the activity of the group 1 G code is suspended for that line The axis word using G codes from group O are G10 G28 G30 and G92 It is an error to include any unrelated words on a line with o flow control Chapter 14 G Codes G c
18. Go to the Permissions tab and check the box for Owner Execute Close the Properties window Now double click the emc2 install sh icon and select Run in Terminal A terminal will appear and you will be asked for your password e When the installation asks if you are sure you want to install the EMC2 packages hit Enter to accept Now just allow the install to finish e When it is done you must reboot System gt Log Out gt Restart the Computer and when you log in again you can run EMC2 by selecting it on the Applications gt CNC Menu If you aren t ready to set up a machine configuration try the sim AXIS configuration it runs a simulated machine that requires no attached hardware Now that the initial installation is done Ubuntu will prompt you when updates of EMC2 or its supporting files are available When they are you can update them easily and automatically with the Update Manager 2 5 Manual installing using apt commands The following few section will describe how to install EMC2 using a console and apt commands If you know a bit about Linux and Debian flavored distributions this might be trivial If not you might consider reading 2 4 First add the repository to etc apt sources list sudo sh c echo deb http www linuxcnc org emc2 dapper emc2 gt gt etc apt sources list sudo sh c echo deb src http www linuxcnc org emc2 dapper emc2 gt gt etc apt sources list CHAPTER 2 INSTALLING
19. Home all axes Load the file to be milled Use the preview plot to verify that the program is correct Put the stock to be milled on the table Set the proper offsets for each axis by jogging and using the Touch Off button Run the program O ON DO oA PP UD To mill the same file again return to step 6 To mill a different file return to step 4 When you re done exit AXIS 9 3 Elements of the AXIS window The AXIS window contains the following elements e A display area that shows a preview of the loaded file in this case axis ngc as well as the current location of the CNC machine s controlled point Later this area will display the path the CNC machine has moved through called the backplot e A menubar and toolbar that allow you to perform various actions Manual Control which allows you to make the machine move turn the spindle on or off and turn the coolant on or off Code Entry also called MDI where G code programs can be entered manually one line at a time e Feed Override which allows you to increase or decrease the speed at which EMC executes the selected program A text display area that shows the G code source of the loaded file e A status bar which shows the state of the machine In this screenshot the machine is turned on does not have a tool inserted and the displayed position is Relative to the machine offset as opposed to Absol
20. In the Interpreter the interpretation of the feed rate is as follows unless inverse time feed rate mode is being used in the RS274 NGC view see Section 14 20 If the parallelism requirement is violated the system builder will have to say how to distinguish clockwise from counter clockwise CHAPTER 12 RETURN MACHINING CENTER OVERVIEW 125 1 For motion involving one or more of the X Y and Z axes with or without simultaneous rota tional axis motion the feed rate means length units per minute along the programmed XYZ path as if the rotational axes were not moving 2 For motion of one rotational axis with X Y and Z axes not moving the feed rate means degrees per minute rotation of the rotational axis 3 For motion of two or three rotational axes with X Y and Z axes not moving the rate is applied as follows Let dA dB and dC be the angles in degrees through which the A B and C axes respectively must move Let D dA dB dC Conceptually D is a measure of total angular motion using the usual Euclidean metric Let T be the amount of time required to move through D degrees at the current feed rate in degrees per minute The rotational axes should be moved in coordinated linear motion so that the elapsed time from the start to the end of the motion is T plus any time required for acceleration or deceleration 12 2 6 Coolant Flood coolant and mist coolant may each be turned on independently The RS274 NG
21. Position in counts when index pulse arrived e FLOAT m5i20 lt board gt enc lt channel gt position Encoder position in user units e FLOAT m5i20 lt board gt enc lt channel gt pos latch Position in user units when index pulse arrived e BIT m5i20 lt board gt enc lt channel gt index Current status of index pulse input e BIT m5bi20 lt board gt enc lt channel gt idx latch Goes true when an index pulse arrives e BIT m5i20 lt board gt enc lt channel gt latch index Bidirectional used to control report index latching e BIT m5i20 lt board gt enc lt channel gt reset count Bidirectional why used to reset counter w e BIT m5i20 lt board gt dac lt channel gt enable Enables DAC if true DAC outputs zero volts if false e FLOAT m5i20 lt board gt dac lt channel gt value Analog output value for PWM DAC in user units see scale and offset 8Ideally the encoders DACs and digital I O would comply with the canonical interfaces defined earlier but they don t Fixing that is on the things to do list 9I don t know what the maximum and minimum if any PWM frequency is it should be documented here Also this is the kind of thing that ideally is controlled by a HAL parameter rather than being set when the driver is initially loaded I don t know if that is possible it depends on the hardware and I don t h
22. The traditional hardware design as described above ends at the edge of the main control Outside the control are a bunch of relatively simple boxes connected together to do whatever is needed Inside the control is a big mystery one huge black box that we hope works HAL extends this traditional hardware design method to the inside of the big black box It makes device drivers and even some internal parts of the controller into smaller black boxes that can be interconnected and even replaced just like the external hardware It allows the system wiring diagram to show part of the internal controller rather than just a big black box And most importantly it allows the integrator to test and modify the controller using the same methods he would use on the rest of the hardware Terms like motors amps and encoders are familiar to most machine integrators When we talk about using extra flexible eight conductor shielded cable to connect an encoder to the servo input board in the computer the reader immediately understands what it is and is led to the question what kinds of connectors will I need to make up each end The same sort of thinking is essential for the HAL but the specific train of thought may take a bit to get on track Using HAL words may seem a bit strange at first but the concept of working from one connection to the next is the same This idea of extending the wiring diagram to the inside of the controller is what HAL is
23. Y Z A B C where all the axis words are optional except that at least one must be used The G0 is optional if the current motion mode is GO This will produce coordinated linear motion to the destination point at the current traverse rate or slower if the machine will not go that fast It is expected that cutting will not take place when a GO command is executing It is an error if e all axis words are omitted If cutter radius compensation is active the motion will differ from the above see Chapter If G53 is programmed on the same line the motion will also differ see Section 14 13 14 2 Gl Linear Motion at Feed Rate For linear motion at feed rate for cutting or not program G1 X Y Z A B C where all the axis words are optional except that at least one must be used The G1 is optional if the current 136 CHAPTER 14 G CODES 137 motion mode is G1 This will produce coordinated linear motion to the destination point at the current feed rate or slower if the machine will not go that fast It is an error if e all axis words are omitted If cutter radius compensation is active the motion will differ from the above see Chapter If G53 is programmed on the same line the motion will also differ see Section 14 13 14 3 G2 G3 Arc at Feed Rate A circular or helical arc is specified using either G2 clockwise arc or G3 counterclockwise arc The axis of the circle or helix must be parallel to the X
24. and should probably be removed from the halemd listing CHAPTER 7 HAL TUTORIAL 55 7 3 3 Making realtime code run To actually run the code contained in the function siggen 0 update we need a realtime thread Eventually halcmd will have a newthread command that can be used to create a thread but that requires some significant internal changes For now we have a component called threads that is used to create a new thread Lets create a thread called test thread with a period of 1mS 1000000nS halcmd loadrt threads namel test thread period1 1000000 Let s see if that worked halcmd show thread Realtime Threads Period FP Name Time Max Time 999849 YES test thread 0 305 9 It did The period is not exactly 1000000nS because of hardware limitations but we have a thread that runs at approximately the correct rate and which can handle floating point functions The next step is to connect the function to the thread halcmd addf siggen 0 update test thread Up till now we ve been using halcmd only to look at the HAL However this time we used the addf add function command to actually change something in the HAL We told halcmd to add the function siggen 0 update to the thread test thread and if we look at the thread list again we see that it succeeded halcmd show thread Realtime Threads Period FP Name Time Max Time 999849 YES test thread 0 O 1 siggen 0 update There is one more step needed before the si
25. as a result input mm encoder counts 787 4 MIN_LIMIT 1000 The minimum limit soft limit for axis motion in user units When this limit is exceeded the controller aborts axis motion MAX LIMIT 1000 The maximum limit soft limit for axis motion in user units When this limit is exceeded the controller aborts axis motion MIN_FERROR 0 010 This is the value by which the axis is permitted to deviate from commanded position at very low speeds If MIN_FERROR is smaller than FERROR the two produce a ramp of error trip points You could think of this as a graph where one dimension is speed and the other is permitted following error As speed increases the amount of following error also increases toward the FERROR value FERROR 1 0 FERROR is the maximum allowable following error in user units If the difference between commanded and sensed position exceeds this amount the controller disables servo calculations sets all the outputs to 0 0 and disables the amplifiers If MIN_FERROR is present in the ini file velocity proportional following errors are used Here the maximum allowable following error is proportional to the speed with FERROR applying to the rapid rate set by TRAJ MAX_VELOCITY and proportionally smaller following errors for slower speeds The maximum allowable following error will always be greater than MIN_FERROR This prevents small following errors for stationary axes from inadvertently aborting motion Small f
26. halcmd loadrt threads namel test thread period1 1000000 halcmd addf siggen 0 update test thread halcmd start halcmd setp siggen 0 amplitude 5 7 4 1 Starting halmeter At this point we have the siggen component loaded and running It s time to start halmeter Since halmeter is a GUI app X must be running halcmd loadusr halmeter At the same time a halmeter window opens on your screen looking something like figure 7 1 CHAPTER 7 HAL TUTORIAL 58 X A HAL Meter x Select Exit Figure 7 1 Halmeter at startup nothing selected XA Select Item to Probe NTE Pins Signals Parameters siggen 1 cosine siggen 1 sine siggen 1 square siggen 1 triangle OK Accept Cancel Figure 7 2 Halmeter source selection dialog CHAPTER 7 HAL TUTORIAL 59 7 4 2 Using halmeter The meter in figure 7 1 isn t very useful because it isn t displaying anything To change that click on the Select button which will open the probe selection dialog figure 7 2 This dialog has three tabs The first tab displays all of the HAL pins in the system The second one displays all the signals and the third displays all the parameters We would like to look at the pin siggen 0 triangle first so click on it then click the OK button The probe selection dialog will close and the meter looks something like figure 7 3 X A HAL Meter NES 3 71923e 00 siggen 1 triangle Select Exit Figure 7
27. is given by the I value which is an offset from the drive line Negative I values indicate external threads and positive I values indicate internal threads Generally the material has been turned to this size before the canned cycle The initial cut depth is given by the J value The first threading cut will be J beyond the thread peak position J is positive even when I is negative The full thread depth is given by the K value The final threading cut will be k beyond the thread peak position K is positive even when I is negative The depth degression is given by the R value R1 0 selects constant depth on successive threading passes R2 0 selects constant area Values between 1 0 and 2 0 select decreasing depth and increasing area Values above 2 0 select decreasing area The compound slide angle Q is the angle in degrees describing to what extent successive passes should be offset along the drive line This is used to cause one side of the tool to remove more material than the other A positive Q value causes the leading edge of the tool to cut more heavily Typical values are 29 29 5 or 30 The number of spring passes is given by the H value Spring passes are additional passes at full thread depth If no additional passes are desired program HO Each pass begins at a position on the drive line It consists of 1 An X traverse to the depth for this pass CHAPTER 14 GCODES 143
28. many intervening lines 0100 call Inside a subroutine O return can be executed This immediately returns to the calling code just as though O0 endsub was encountered O call takes up to 30 optional arguments which are passed to the subroutine as 1 2 N Parameters from N 1 to 30 have the same value as in the calling context On return from the subroutine the previous values parameters 1 through 30 regardless of the number of arguments will be restored to the values they had before the call Because 1 2 3 is parsed as the number 123 the parameters must be enclosed in square brackets The following calls a subroutine with 3 arguments 0200 call 1 2 3 Subroutine bodies may not be nested They may only be called after they are defined They may be called from other functions and may call themselves recursively if it makes sense to do so The maximum subroutine nesting level is 10 Subroutines do not have return values but they may change the value of parameters above 30 and those changes will be visible to the calling code 153 CHAPTER 16 O CODES 154 16 2 Looping do while endwhile break continue The while loop has two structures while endwhile and do while In each case the loop is exited when the while condition evaluates to false draw a sawtooth shape F100 1 0 0101 whil 1 1t 10 G1 X0 G1 Y 1
29. stg lt channel gt position scale The number of counts user unit to convert from counts to units F E E E B LOAT stg lt channel gt dac offset Sets the offset for the corresponding DAC LOAT stg lt channel gt dac gain Sets the gain of the corresponding DAC LOAT stg lt channel gt adc offset Sets the offset of the corresponding ADC LOAT stg lt channel gt adc gain Sets the gain of the corresponding ADC T stg out lt pinnum gt invert Inverts an output pin The invert parameter determines whether an output pin is active high or active low If invert is FALSE setting the HAL out pin TRUE drives the physical pin high and FALSE drives it low If invert is TRUE then setting the HAL out pin TRUE will drive the physical pin low 8 4 5 Functions E in lt pinnu E UNCT S UNCT S UNCT S UNCT Ss UNCT S tg capture position Reads the encoder counters from the axis lt channel gt tg write dacs Writes the voltages to the DACs tg read adcs Reads the voltages from the ADCs tg di read Reads physical in pins of all ports and updates all HAL in and m gt not pins tg do write Reads all HAL out pins and updates all physical output pins 7if IIOO is defined there are 16 input pins in 00 in 15 and 16 output pins out 00 out 15 and they correspond to PORTs ABCD in 00 is PORTA O out 15 is PORTD 7 CHAPTER 8 HARDWARE
30. the Home All button or the Ctrl HOME key will send all axes home Otherwise the button will read Home and will send the current axis home Pressing the HOME key sends the current axis home even if a homing sequence is defined Depending on your configuration homing may just set the axis value to be the absolute position 0 0 or it may make the machine move to a specific home location through use of home switches See section 5 4 for more information on homing By pressing Touch Off or the END key the G54 offset for the current axis is changed so that the current axis value will be the specified value Expressions may be entered using the rules for rs274ngc programs except that variables may not be referred to The resulting value is shown as a number Figure 9 3 Touch Off Enter coordinate relative to workpiece 0 707107 OE Cancel By pressing Override Limits the machine will temporarily be permitted to jog outside the limits defined in the ini file 9 3 4 2 The Spindle group The buttons on the first row select the direction for the spindle to rotate Counterclockwise Stopped Clockwise The buttons on the next row increase or decrease the rotation speed The checkbox on the third row allows the spindle brake to be engaged or released Depending on your machine configuration not all the items in this group may appear 9 3 4 3 The Coolant group The two buttons allow
31. the radius of arc AB need only be slightly larger than the maximum possible deviation of the radius of the tool from the exact size Also for a tool path contour the side chosen for compensation should be the one to use if the tool is oversized As mentioned earlier if the tool is undersized the interpreter will switch sides Simple Method If the contour is a material edge contour and there is a convex corner somewhere on the contour a simpler method of making an entry is available See Figure 12 First pick a convex corner D Decide which way you want to go along the contour from D In our example we are keeping the tool to the left of the contour and going next towards F Extend the line FD if the next part of the contour is an arc extend the tangent to arc FD from D to divide the area outside the contour near D into two regions Make sure the center of the tool is currently in the region on the same side of the extended line as the material inside the contour near D If not move the tool into that region In the example point E represents the current location of the center of the tool Since it is on the same side of line DF as the shaded triangle no additional move is needed Now write a line of NC code that turns compensation on and moves to point D N0010 G41 G1 X2 Y2 turn E compensation on and make entry move This method will also work at a concave corner on a tool path contour if the ac tual tool is oversized but it
32. then it is the ideal position for instance the exact coordinate given in a GO command If it is Ac tual then it is the position the machine has actually been moved to These values can differ for several reasons Following error deadband encoder resolution or step size For instance if you command a movement to X 0 0033 on your mill but one step of your stepper motor is 0 00125 then the Commanded position will be 0 0033 but the Actual position will be 0 0025 2 steps or 0 00375 3 steps 9 3 2 2 Preview Plot When a file is loaded a preview of it is shown in the display area Fast moves such as those produced by the GO command are shown as dotted green lines Moves at a feed rate such as those produced by the G1 command are shown as solid white lines Dwells such as those produced by the G4 command are shown as small X marks CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 94 9 3 2 3 Program Extents The extents of the program in each axis are shown At each end the least or greatest coordinate value is indicated In the middle the difference between the coordinates is shown In Figure 9 1 the X extent of the file is from 2 05 to 2 09 inches a total of 4 13 inches When some coordinates exceed the soft limits in the ini file the relevant dimension is shown in a different color Here the maximum limit is exceeded on the X axis 9 3 2 4 Tool Cone The location of the tip of the tool
33. 0 0 0 Example 2 Absolute Position G81 Suppose the current position is 1 2 3 and the following line of NC code is interpreted G91 G81 G98 X4 Y5 Z 0 6 R1 8 L3 This calls for incremental distance mode G91 and OLD_Z retract mode G98 It also calls for the G81 drilling cycle to be repeated three times The X value is 4 the Y value is 5 the Z value is 0 6 CHAPTER 22 CANNED CYCLES 180 and the R value is 1 8 The initial X position is 5 1 4 the initial Y position is 7 2 5 the clear Z position is 4 8 1 8 3 and the Z position is 4 2 4 8 0 6 OLD_Z is 3 The first preliminary move is a traverse along the Z axis to 1 2 4 8 since OLD_Z lt clear Z The first repeat consists of 3 moves 1 a traverse parallel to the XY plane to 5 7 4 8 2 a feed parallel to the Z axis to 5 7 4 2 3 a traverse parallel to the Z axis to 5 7 4 8 The second repeat consists of 3 moves The X position is reset to 9 5 4 and the Y position to 12 7 5 1 a traverse parallel to the XY plane to 9 12 4 8 2 a feed parallel to the Z axis to 9 12 4 2 3 a traverse parallel to the Z axis to 9 12 4 8 The third repeat consists of 3 moves The X position is reset to 13 9 4 and the Y position to 17 12 5 1 a traverse parallel to the XY plane to 13 17 4 8 2 a feed parallel to the Z axis to 13 17 4 2 3 a traverse parallel to the Z axis to 13 17 4 8 First Second Third repeat repeat repeat Preliminary move
34. 0 tool changed create a signal for spindle on newsig spindle on bit connect the controller to it linkps motion spindle on gt spindle on connect it to a physical pin linksp spindle on gt parport 0 pin 09 out INote we are only presenting one axis to keep it short all others are similar 2Refer to section 8 1 for additional information CHAPTER 4 BASIC CONFIGURATIONS FOR A STEPPER BASED SYSTEM 25 You th might use something like this to enable chopper drives when machine ON d Xen signal is defined in core_stepper hal linksp Xen gt parport 0 pin 01 out If you want active low for this pin invert it like this setp parport 0 pin 01 out invert 1 As lin to ample home switch on the X axis axis 0 make a signal k the incoming parport pin to the signal then link the signal EMC s axis 0 home switch input pin newsig Xhome bit linkp s parport 0 pin 10 in gt Xhome linksp Xhome gt axis 0 home sw in Sha set us you newsig Xlimits bit red home switches all on one parallel port pin that s ok hook the same signal to all the axes but be sure to HOME_1IS_SHARED and HOME SEQUENCE in the ini file See the
35. 04 enc 05 B input 11 in 05 enc 05 index input 13 in 06 enc 06 A input 15 in 07 enc 06 B input 17 in 08 enc 06 index input 19 in 09 enc 07 A input 21 in 10 enc 07 B input 23 in 11 enc 07 index input 25 in 12 27 in 13 29 in 14 31 in 15 33 out 00 35 out 01 37 out 02 39 out 03 41 out 04 43 out 05 45 out 06 47 out 07 49 Power 5 V or 3 3V all even pins Ground Note This is the intended pinout of P3 Unfortunately in the current FPGA configuration distributed with EMC2 the secondary encoders enc 04 enc 05 enc 06 and enc 07 are wrongly configured The input pins for enc 04 and enc 05 partly overlap as do the pins for enc 06 and enc 07 Thus it is possible to use enc 04 and enc 06 simultaneously but using enc 04 and enc 05 is not possible since counts on enc 04 will make the count on enc 05 jump by 1 If you are using pins in 00 to in 11 as general purpose inputs you are not affected by this bug 8 5 5 3 Connector P4 The index mask masks the index input of the encoder so that the encoder index can be combined with a mechanical switch or opto detector to clear or latch the encoder counter only when the mask input bit is in proper state selected by mask polarity bit and encoder index occurs This is useful for homing The behaviour of these pins is controlled by the Counter Control Register CCR however there is currently no function in the driver to change the CCR See REGMAP4 for a description of the
36. 10 X1 1 1 1 0101 endwhile Inside a while loop O break immediately exits the loop and O continue immediately skips to the next evaluation of the while condition If it is still true the loop begins again at the top If it is false it exits the loop 16 3 Conditional if else endif The if conditional executes one group of statements if a condition is true and another if it is false Set feed rate depending on a variable 0102 if 2 GT 5 F100 0102 else F200 0102 endif 16 4 Indirection The O value may be given by a parameter or calculation O 101 2 call Chapter 17 Other Codes 17 1 F Set Feed Rate To set the feed rate program F The application of the feed rate is as described in Section 12 2 5 unless inverse time feed rate mode is in effect in which case the feed rate is as described in Section 14 20 17 2 S Set Spindle Speed To set the speed in revolutions per minute rpm of the spindle program s The spindle will turn at that speed when it has been programmed to start turning Itis OK to program an S word whether the spindle is turning or not Ifthe speed override switch is enabled and not set at 100 the speed will be different from what is programmed It is OK to program SO the spindle will not turn if that is done It is an error if e the S number is negative As described in Section 14 18 5 if a G84 tapping canned cycle is active an
37. 135 139 G2 135 137 G20 135 139 G21 135 139 G28 135 140 G3 135 137 G30 135 140 G33 135 138 G38 2 135 140 G4 135 139 G40 135 140 G41 135 140 G42 135 140 G43 135 141 G49 135 141 G53 135 141 171 G54 135 141 171 173 G55 135 141 171 173 G56 135 141 171 173 G57 135 141 171 173 G58 135 141 171 173 G59 135 141 171 173 G59 1 135 141 171 173 G59 2 135 141 171 173 G59 3 135 141 171 173 G61 142 G61 1 142 G64 142 G76 142 G80 135 142 178 200 INDEX G81 135 143 145 179 G82 135 146 181 182 G83 135 146 G84 135 147 182 G85 135 147 183 G86 135 147 183 G87 135 147 183 G88 135 147 185 G89 135 143 147 185 G90 135 148 G91 135 148 G92 135 148 171 173 G92 1 135 148 174 G92 2 135 148 174 G92 3 135 148 174 G93 135 149 G94 135 149 G98 135 149 185 G99 135 149 185 GNU Linux 3 GPL 4 HAL 5 12 24 28 29 43 HAL Component 45 HAL Function 45 HAL Parameter 45 HAL Physical Pin 45 HAL Pin 45 HAL Signal 45 HAL Thread 46 HAL Type 45 hal ax5214h 47 hal m5i20 47 hal motenc 47 hal parport 47 hal ppmc 47 hal stg 47 hal vti 47 halemd 47 halmeter 47 halscope 47 halui 46 HOME 40 Home 105 193 HOME IGNORE LIMITS 40 HOME IS SHARED 40 HOME LATCH VEL 38 HOME OFFSET 40 HOME SEARCH VEL 34 38 HOME SEQUENCE 40 HOME USE INDEX 40 if 15
38. 2 000 Carbide Insert Face Mill as shown in the table but the only fornfat requirement is that there be at least one space or tab after each of the first three entries on a line and Dspace tab or newline at the end of the fourth entry The meanings of the columns and the pe of fata to be put in each are as follows The POC column contains an unsigned integer which represents the pocket number slot number of the tool carousel slot in which the tool is placed The entries in this column must all be different The FMS column contains an unsigned integer which represents a code number for the tool The user may use any code for any tool as long as the codes are unsigned integers The LEN column contains a real number which represents the tool length offset This number will be used if tool length offsets are being used and this pocket is selected This is normally a positive real number but it may be zero The DIAM column contains a real number This number is used if tool radius compensation is turned on using this pocket number If the programmed path during compensation is the edge of the material being cut this should be a positive real number representing the measured diameter of the tool If the programmed path during compensation is the path of a tool whose diameter is nominal this should be a small number positive negative or zero representing the difference between the measured diameter of the too
39. 3 Halmeter displaying the value of a pin You should see the value changing as siggen generates its triangle wave Halmeter refreshes its display about 5 times per second If you want to quickly look at a number of pins you can use the Accept button in the source selection dialog Click on Select to open the dialog again This time click on another pin like siggen 0 cosine and then click Accept When you click Accept the meter immediately begins to display the newly selected item but the dialog does not close Try displaying a parameter instead of a pin Click on the Parameters tab then select a parameter and click Accept again You can very quickly move the meter probes from one item to the next with a couple of clicks To shut down halmeter just click the exit button If you want to look at more than one pin signal or parameter at a time you can just start more halmeters The halmeter window was intentionally made very small so you could have a lot of them on the screen at once 3Halmeter is due for a rewrite The rewrite will do a number of things to make it nicer Scientific notation will go away it is a pain to read Some form of ranging including autoranging will be added to allow it to display a wide range of numbers without using scientific notation An analog bar graph display will also be added to give a quick indication of trends When the rewrite is done these screenshots and the
40. 39 and two blocks of 4 bits 40 43 and 44 47 If more than one board is installed the data for the second board follows the first As an example the string 0x220 IIIOIIOO 0x300 OIOOIOIO installs drivers for two boards The first board is at address 0x220 and has 36 inputs 0 19 and 24 39 and 12 outputs 20 23 and 40 47 The second board is at address 0x300 and has 20 inputs 8 15 24 31 and 40 43 and 28 outputs 0 7 16 23 32 39 and 44 47 8 3 2 Removing emc2S halcmd unloadrt hal _ax5214 8 3 3 Pins e BIT ax5214 lt boardnum gt out lt pinnum gt Drives a physical output pin e BIT ax5214 lt boardnum gt in lt pinnum gt Tracks a physical input pin e BIT ax5214 lt boardnum gt in lt pinnum gt not Tracks a physical input pin inverted For each pin lt boardnum gt is the board number starts at zero and lt pinnum gt is the I O channel number 0 to 47 Note that the driver assumes active LOW signals This is so that modules such as OPTO 22 will work correctly TRUE means output ON or input energized If the signals are being used directly without buffering or isolation the inversion needs to be accounted for The in HAL pin is TRUE if the physical pin is low OPTO 22 module energized and FALSE if the physical pin is high OPTO 22 module off The in lt pinnum gt not HAL pin is inverted it is FALSE if the physical pin is low OPTO 22 module energized By connecting a signal to one or the
41. 5 0 halcmd setp siggen 0 amplitude 5 emc2 Check the parameters and pins again halcmd setp siggen 0 amplitude 5 halcmd show param Parameters Owner Type Dir Value Name 32769 float RW 5 00000e 00 siggen 0 amplitude 32769 float RW 1 00000e 00 siggen 0 frequency 32769 float RW 0 00000e 00 siggen 0 offset 32769 32 RO 397 siggen 0 update time 32769 s32 RW 109100 siggen 0 update tmax halcmd show pin Component Pins Owner Type Dir Value Name 32769 float OUT 4 78453e 00 siggen 0 cosine 32769 float OUT 4 53106e 00 siggen 0 sawtooth 32769 float OUT 1 45198e 00 siggen 0 sine 32769 float OUT 5 00000e 00 siggen 0 square 32769 float OUT 4 02213e 00 siggen 0 triangle Note that the value of parameter siggen 0 amplitude has changed to 5 000 and that the pins now have larger values 7 3 5 Saving the HAL configuration Most of what we have done with halcmd so far has simply been viewing things with the show command However two of the commands actually changed things As we design more complex systems with HAL we will use many commands to configure things just the way we want them HAL has the memory of an elephant and will retain that configuration until we shut it down But what about next time We don t want to manually enter a bunch of commands every time we want to use the system We can save the configuration of the entire HAL with a single command halcmd save components loadrt threads namel test threa
42. All of the parameters shown in Table 12 3 are required parameters and must be included in any CHAPTER 12 RETURN MACHINING CENTER OVERVIEW 129 parameter file except that any parameter representing a rotational axis value for an unused axis may be omitted An error will be signalled if any required parameter is missing A parameter file may include any other parameter as long as its number is in the range 1 to 5400 The parameter numbers must be arranged in ascending order An error will be signalled if not Any parameter included in the file read by the Interpreter will be included in the file it writes as it exits The original file is saved as a backup file when the new file is written Comments are not preserved when the file is written Table 12 3 Parameter File Format Parameter Number Parameter Value Comment 5161 0 0 G28 Home X 5162 0 0 G28 Home Y 12 6 Coordinate Systems In the RS274 NGC language view a machining center has an absolute coordinate system and nine program coordinate systems You can set the offsets of the nine program coordinate systems using G10 L2 Pn n is the number of the coordinate system with values for the axes in terms of the absolute coordinate system See Section 14 6 You can select one of the nine systems by using G54 G55 G56 G57 G58 G59 G59 1 G59 2 or G59 3 see Section 14 14 It is not possible to select the absolute coordinate system directly You can offset t
43. CCR Memec2 src hal drivers m5i20_HM5 4E h dated 2005 06 07 12emc2 src hal drivers m5i20 REGMAP4E CHAPTER 8 HARDWARE DRIVERS m5i20 card connector P4 Function HAL pin Secondary Function HAL pin 1 in 16 enc 00 index mask 3 in 17 enc 01 index mask 5 in 18 enc 02 index mask 7 in 19 enc 03 index mask 9 in 20 11 in 21 13 in 22 15 in 23 17 in 24 enc 04 index mask 19 in 25 enc 05 index mask 21 in 26 enc 06 index mask 23 in 27 enc 07 index mask 25 in 28 27 in 29 29 in 30 31 in 31 33 out 08 35 out 09 37 out 10 39 out 11 41 out 12 43 out 13 45 out 14 47 out 15 49 Power 5 V or 3 3V all even pins Ground 8 5 5 4 LEDs 85 The status LEDs will monitor one motion channel set by the m5i20 lt board gt 1led view parameter A call to m5i20 lt board gt misc update is required to update the LEDs LED name Output LEDO IRQLatch LED1 enc lt channel gt A LED2 enc lt channel gt B LED3 enc lt channel gt index LED4 dac lt channel gt DIR LED5 dac lt channel gt LED6 dac lt channel gt enable LED7 watchdog timeout 8 6 Vital Systems Motenc 100 and Motenc LITE The Vital Systems Motenc 100 and Motenc LITE are 8 and 4 channel servo control boards The Motenc 100 provides 8 quadrature encoder counters 8 analog inputs 8 analog outputs 64 687 digital inputs and 32 digital
44. Example 5 Relative position R gt Z 22 4 G82 Cycle The G82 cycle is intended for drilling CHAPTER 22 CANNED CYCLES 182 O Preliminary motion as described above 1 Move the Z axis only at the current feed rate to the Z position 2 Dwell for the given number of seconds 3 Retract the Z axis at traverse rate to clear Z The motion of a G82 canned cycle looks just like g81 with the addition of a dwell at the bottom of the Z move The length of the dwell is specified by a p word in the g82 block G90 G82 G98 X4 Y5 Z1 5 R2 8 P2 Would be equivalent to example 2 above with a dwell added at the bottom of the hole 22 5 G83 Cycle The G83 cycle is intended for deep drilling or milling with chip breaking The dwell in this cycle causes any long stringers which are common when drilling in aluminum to be cut off This cycle takes a Q value which represents a delta increment along the Z axis Machinists often refer to this as peck drilling O Preliminary motion as described above 1 Move the Z axis only at the current feed rate downward by delta or to the Z position whichever is less deep 2 Dwell for 0 25 second 3 Retract at traverse rate to clear Z 4 Repeat steps 1 3 until the Z position is reached 5 Retract the Z axis at traverse rate to clear Z NIST lists the elements of the command as G83 X Y Z A B C R L Q I find this command very handy for many of my deep drilling projects I have not tried to us
45. Help Rows then Columns Down Milling 0 25 15 ii 0 0625 0 012 Ball End Secondary 45 0 OK Cancel ESTOP 23 1 What is a depth map Position Relative Actual Filtering A depth map is a greyscale image where the brightness of each pixel corresponds to the depth or height of the object at each point 23 2 Integrating image to gcode with the AXIS user interface Add the following lines to your ini file to make AXIS automatically invoke image to gcode when you open a png gif or pg image 188 CHAPTER 23 IMAGE TO GCODE MILLING DEPTH MAPS 189 PROGRAM_EXTENSION png gif jpg Grayscale Depth Image png image to gcod gif image to gcod jpg image to gcod 23 3 Using image to gcode Start image to gcode either by opening an image file in AXIS or by invoking image to gcode from the terminal as follows image to gcode torus png gt torus ngc Verify all the settings in the right hand column then press OK to create the gcode Depending on the image size and options chosen this may take from a few seconds to a few minutes If you are loading the image in AXIS the gcode will automatically be loaded and previewed once image to gcode completes In AXIS hitting reload will show the image to gcode option screen again allowing you to tweak them 23 4 Option Reference 23 4 1 Units Specifies whether to use G20 inches or G21 mm in the generated g cod
46. If invert is TRUE then setting the HAL out pin TRUE will drive the physical pin low CHAPTER 8 HARDWARE DRIVERS LLONC CLA LSN NEA ATAT NTO E 2 a Z 9 PIS 2 DS E 2 0 NADIA 0 Z SOEK 16 s oa S iZ LAN lA lA Sue iJ o gt a yu E gt S S g 5 of Z J Zl 8 el l JE lt 2 2 al leal ela tele ef 3 2 als is las 6 lt S 2 3 3 EE E lt Des ann s e rl Ese o A E al ale A os ale we DER e L T a a a a a E E A E O x A H S NAAA MA oy La a La LO A Y Y Y LEI SE A QDAOOQQOOQOLIOCIE O Ko lt oO NJ E eS lt NES IN E A 2 IN oO 6 IN la ll LA ll bl bl ll ll ll ll Ll 5 8 if E A o 3 Z 2 Sta dal tel lel hel teh LER hell bet bel chs a 2 E I E 28 E Jel E El ell E E 2 S INICIAN a a a jel 8 gt Gi y E ia pe E En E SE El El S El El al El sel el
47. Name 03 float W 0 00000e 00 siggen 0 cosine 03 float W 0 00000e 00 siggen 0 sawtooth 03 float W 0 00000e 00 siggen 0 sine 03 float W 0 00000e 00 siggen 0 square 03 float W 0 00000e 00 siggen 0 triangle 02 s32 W 0 freggen 0 counts 02 bit W FALSE freqgen 0 dir 02 float W 0 00000e 00 freqgen 0 position 02 bit W FALSE freggen 0 step 02 float R 0 00000e 00 fregqgen 0 velocity 02 s32 W 0 freggen 1l counts 02 bit W FALSE freqgen 1 dir 02 float W 0 00000e 00 freagen l position 02 bit W FALSE freqgen 1 step 02 float R 0 00000e 00 freqgen 1 velocity halcmd show param Parameters Owner Type Dir Value Name 03 float W 1 00000e 00 siggen 0 amplitude The at the end of a long line indicates line wrapping needed for formatting this document When entering the commands at the command line simply skip the do not hit enter and keep typing from the following line CHAPTER 7 HAL TUTORIAL 61 03 float W 1 00000e 00 siggen 0 frequency 03 float W 00000e 00 siggen 0 offset 02 u32 W 000000001 freqgen 0 dirhold 02 u32 W 000000001 freagen 0 dirsetup 02 float R 0 00000e 00 freqgen 0 frequency 02 float W 0 00000e 00 freqgen 0 maxaccel 02 float W 1 00000e 15 freqgen 0 maxfreq 02 float W 1 00000e 00 freqgen 0 position scale 02 s32 R 0 freggen 0 rawcounts 02 u32 W 000000001 freqgen 0 steplen 02 u32 W 000000001 freqgen 0 stepspace 02 float W 1 00000e 00 freqgen 0
48. THE EMC2 SOFTWARE 16 Or replace dapper above with breezy if you still use Ubuntu 5 10 Breezy Badger Then update amp get emc2 sudo apt get update sudo apt get install emc2 This command will install the emc2 package along with all dependencies You might get warnings that the packages are from an untrusted source this means your com puter doesn t recognize the GPG signature on the packages To correct that issue the following commands gpg keyserver pgpkeys mit edu recv key BC92B87F gpg a export BC92B87F sudo apt key add 3AXIS is now part of emc2 You don t need to install emc2 axis as previously 4The dependencies are one of the nicest thing in Debian based distributions They assure you have everything installed that you need In the case of emc2 it s even a RT patched kernel and all needed libraries Part II Configuring EMC2 Chapter 3 Running EMC2 One advantage of EMC has always been it s ability to run a wide variety of machines and devices This flexibility can be a bit scary when you first begin to work with the system The material in this chapter will show you how to start up EMC2 using sample configurations and how to copy these sample configurations so that you are ready to create the configuration you need for your machine 3 1 Configuration Selector The installation of EMC2 includes quite a few different configurations that can be started from a graphical screen This con
49. UNITS 0 03937007874016 then we have defined our user units as inches Using similar arithmetic we could set our units to most any value we wanted You will want to use inches or millimeters for your minimill but some who run vehicles with the EMC2 have been known to set units to kilometers or miles After we have decided upon a value for the units for an axis we tell the EMC2 how may step pulses or encoder pulses it should send or read for each unit of distance to be traveled Once we have done this the EMC2 knows how to count units of distance However it is very important to understand that this counting of distance is different from the commanding of distance You can command distance in millimeters or inches without even thinking about the units that you defined There are G codes that allow you to switch easily between metric and imperial 1 7 2 Some things we may not want to change Within the EMC2 code are a few things that are not easily changed We call these defaults There are connections that have been made between the running components of the EMC2 that we can not easily change We ll see that there are displays and buttons and keyboard keys that are not easily shifted about We ll learn about and get used to these in the chapters ahead 1 7 3 Some things we will need to change The EMC2 is configured with files that are read at startup and used to override the compiled de faults No real controller will likely use the compiled
50. X or Y axis value and move towards a low X or Y axis value e Alternating Start on the same end of the X or Y axis travel that the last move ended on This reduces the amount of traverse movements e Up Milling Start milling at low points moving towards high points e Down Milling Start milling at high points moving towards low points 23 4 11 Depth units The top of material is always at Z 0 The deepest cut into the material is Z depth 23 4 12 Step Over pixels The distance between adjacent rows or columns To find the number of pixels for a given units distance compute distance pixel size and round to the nearest whole number For example if pixel size 006 and the desired step over distance 015 then use a Step Over of 2 or 3 pixels because 015 006 2 5 23 4 13 Tool Diameter The diameter of the cutting part of the tool CHAPTER 23 IMAGE TO GCODE MILLING DEPTH MAPS 191 23 4 14 Safety Height The height to move to for traverse movements image to gcode always assumes the top of material is at Z 0 23 4 15 Tool Type The shape of the cutting part of the tool Possible tool shapes are e Ball End e Flat End e 45 degree vee e 60 degree vee 23 4 16 Lace bounding This controls whether areas that are relatively flat along a row or column are skipped This option only makes sense when both rows and columns are being milled Possible bounding options are e None Rows and columns are both
51. accompanying text will be revised to match the new version CHAPTER 7 HAL TUTORIAL 60 7 5 A slightly more complex example Up till now we have only loaded one HAL component But the whole idea behind the HAL is to allow you to load and connect a number of simple components to make up a complex system The next example will use two components Before we can begin building this new example we want to start with a clean slate If you just finished one of the previous examples we need to remove the all components and reload the RTAPI and HAL libraries halcmd exit emc2S halrun 7 5 1 Installing the components Now we are going to load the step pulse generator component For a detailed description of this component refer to section For now we can skip the details and just run the following commands halrun loadrt freqgen step type 0 0 halcmd loadrt siggen halcmd loadrt threads namel fast fp1 0 period1 50000 name2 slow period2 1000000 The first command loads two step generators both configured to generate stepping type O The second command loads our old friend siggen and the third one creates two threads a fast one with a period of 50 micro seconds and a slow one with a period of 1mS The fast thread doesn t support floating point functions As before we can use halcmd show to take a look at the HAL This time we have a lot more pins and parameters than before halcmd show pin Component Pins Owner Type Dir Value
52. amp B configured as Input Port C amp D configured as Output 8 4 2 Removing emc2 halcmd unloadrt hal_stg 5a motion control card usually is a board containing devices to control one or more axes the control devices are usually DAC s to set an analog voltage encoder counting chips for feedback etc Shint after starting up the driver dmesg can be consulted for messages relevant to the driver e g autodetected version number and base address CHAPTER 8 HARDWARE DRIVERS 80 8 4 3 Pins s E E 32 stg lt channel gt counts Tracks the counted encoder ticks LOAT stg lt channel gt position Outputs a converted position LOAT stg lt channel gt dac value Drives the voltage for the corresponding DAC FLOAT stg lt channel gt adc value Tracks the measured voltage from the corresponding ADC T stg in lt pinnum gt Tracks a physical input pin T stg in lt pinnum gt not Tracks a physical input pin but inverted T stg out lt pinnum gt Drives a physical output pin For each pin lt channe1 gt is the axis number and lt pinnum gt is the logic pin number of the STG The in HAL pin is TRUE if the physical pin is high and FALSE if the physical pin is low The in lt pinnum gt not HAL pin is inverted it is FALSE if the physical pin is high By connecting a signal to one or the other the user can determine the state of the input 8 4 4 Parameters e FLOAT
53. an alignment move and two entry moves The entry moves given above will be used as an example Here is the relevant code again N0010 Gl X1 Y4 5 make aligment move to point C N0020 G41 Gl Y3 5 turn compensation on and make first entry move to point B N0030 G3 X2 Y2 5 Il make second entry move to point A CHAPTER 20 TOOL FILE AND COMPENSATION 167 See Figure 11 The figure shows the two entry moves but not the alignment move First pick a point A on the contour where it is convenient to attach an entry arc Specify an arc outside the contour which begins at a point B and ends at A tangent to the contour and going in the same direction as it is planned to go around the contour The radius of the arc should be larger than half the diameter given in the tool table Then extend a line tangent to the arc from B to some point C located so that the line BC is more than one radius long C 1 4 5 After the construction is finished the code is written in the reverse order from B 1 3 5 the construction Cutter radius com pensation is turned on after the align ment move and before the first entry move In the code above line N0010 is the alignment move line N0020 turns compensation on and makes the first entry move and line N0030 makes the second entry move Figure 11 Cutter Radius Compensation Entry Moves In this example the arc AB and the line BC are fairly large but they need not be For a tool path contour
54. and the way that it worked on his Grizzly minimill The following quoted para graphs are extracted from his paper which is available in several text formats in the dropbox at http www linuxcnc org CHAPTER 21 COORDINATE SYSTEM AND G92 OFFSETS 174 21 4 1 The G92 commands This set of commands include G92 This command when used with axis names sets values to offset variables G92 1 This command sets zero values to the g92 variables G92 2 This command suspends but does not zero out the g92 variables G92 3 This command applies offset values that have been suspended When the commands are used as described above they will work pretty much as you would expect A user must understand the correct ways that the g92 values work They are set based upon the location of each axis when the 892 command is invoked The NIST document is clear that To make the current point have the coordinates xO yO and zO you would use g92 x0 yO z0 G92 does not work from absolute machine coordinates It works from current location G92 also works from current location as modified by any other offsets that are in effect when the g92 command is invoked While testing for differences between work offsets and actual offsets it was found that a g54 offset could cancel out a g92 and thus give the appearance that no offsets were in effect However the g92 was still in effect for all coordinates and did produce expected work offsets for the other coordinate syste
55. can turn off power to the motors Most of the time when we abort or E Stop it s because something went wrong Perhaps we broke a tool and want to change it We switch to manual mode and raise the spindle change tools and assuming that we got the length the same get ready to go on If we return the tool to the same place where the abort was issued the EMC will work perfectly It is possible to move the restart line back or ahead of where the abort happened If you press the Back or Ahead buttons you will see a blue highlight that shows the relationship between the abort line and the one on which the EMC will start up again By thinking through what is happening at the time of the restart you can place the tool tip where it will resume work in an acceptable manner You will need to think through things like tool offsets barriers to motion along a diagonal line and such before you press the Restart button 11 5 Left Column There are two columns below the control line The left side of the screen displays information of interest to the operator There are very few buttons to press here 11 5 1 Axis Position Displays The axis position displays work exactly like they do with tkemc The color of the letters is important e Red indicates that the machine is sitting on a limit switch or the polarity of a min or max limit is set wrong in the ini file e Yellow indicates that the machine is ready to be homed e Green indicates that the machine h
56. case EMC needs to ignore that limit during homing The default value for this parameter is NO 5 4 3 4 HOME_USE_INDEX HOME_USE_INDEX is a single bit settable in the AXIS_ section It specifies whether or not there is an index pulse If the flag is true HOME_USE_INDEX YES EMC will latch on the rising edge of the index pulse If false EMC will latch on either the rising or falling edge of the home switch depending on the signs of search_vel and latch_vel If HOME_SEARCH_VEL is zero the latch phase is skipped and this parameter is ignored The default value is NO 5 4 3 5 HOME_OFFSET HOME_OFFSET is a value setable from the ini in the AXIS _ section It contains the location of the home switch or index pulse in joint coordinates It can also be treated as the distance between the point where the switch or index pulse is latched and the zero point of the joint After detecting the index pulse EMC sets the joint coordinate of the current point to HOME_OFFSET The default value is zero 5 4 3 6 HOME HOME is a value setable from the ini in the AXIS _ section It is the position that the joint will go to upon completion of the homing sequence After detecting the index pulse and setting the coordinate of that point to HOME_OFFSET EMC makes a move to HOME as the final step of the homing process The default value is zero Note that even if this parameter is the same as HOME_OFFSET the axis will slightly overshoot
57. code programs or to tell why the machine stopped running As you work your way through this text you will be learning bit by bit how to set up and run a machine with your copy of the EMC2 software While you are learning about setting up and running a minimill here you will be thinking of other applications and other capabilities These are the topics of the other linuxcnc org handbooks 1 7 Thinking Like An Integrator The biggest task of a machine integrator is figuring out how to connect a PC running the EMC2 toa machine and configuring the software so that it runs the machine correctly Most of this is not the topic of this book but there are a few things that you will have to understand in order to make our little minimill work for us like we expect it to work CHAPTER 1 THE ENHANCED MACHINE CONTROL 12 1 7 1 Units Units can be confusing You might ask Does it work in inches feet centimeters millimeters or what There are several possible answers to this question but the best one is that it works in the units that you set it to work in At a machine level we set each axis s units to some value using an INI variable that looks like this UNITS 1 or UNITS 0 03937007874016 The long number above is the distance represented by one millimeter if we convert it into inches So you say the EMC2 uses millimeters internally If we use UNITS 1 then we have defined our user units as millimeters If we use
58. coordinate but it does affect actual machine position until you program a z move Y UA Test tool length program x Y Boi v z 3D Tool 1 is 1 inch long N01 Gl F15 X0 YO ZO a NO2 G43 H1 ZO X1 wales vA ene NO3 G49 X0 Z0 me on command N04 GO X2 943 hI NO5 Gl G43 H1 G4 P10 Z0 X3 20 x1 NO6 G49 X2 ZO N07 GO XO Relative motion Machine motion CHAPTER 20 TOOL FILE AND COMPENSATION 162 The effect of this is that in most cases the machine will pick up the offset as a ramp during the next Xyz move after the g43 word 20 4 Cutter Radius Compensation Cutter Diameter Compensation also called Cutter Radius Compensation is something that was obviously added onto the RS 274D specification at the demand of users as it is VERY useful but the implementation was poorly thought out The purpose of this feature is to allow the programmer of the tool path program to virtualize the tool path so that the control can at run time determine the correct offset from the surface to be cut based on the tools available If you resharpen the side cutting edges of end mills then they will end up smaller than the standard diameters The problem is to describe to the control whether the tool is going to be cutting on the outside of an imaginary path or on the inside Since these paths are not necessarily closed paths although they can be it is essentially impossible for the control to know which side of the line it is supposed to of
59. defaults so you will certainly need to edit at least some of these files to reflect the specifics of your machine There are five kinds of configuration files INI NML TBL VAR and HAL files These are reflected in lower case file extensions to a file name They may be named stepper tbl or generic tbl but they do the same thing when they are read by the EMC2 as it starts up Many users copy these and name them for the specific machine A set of these files named Sherlinemill ini Sherlinemill var Sherlinemill tbl and Sherlinemill nml are certainly more descriptive than a bunch of files named generic These files each contain specific information for your CNC e stepper ini contains all the machine parameters such as servo gains scale factors cycle times units etc and will certainly need to be edited e emc nml contains communication settings for shared memory and network ports you may need to override on your system although it is likely that you can leave these settings alone CHAPTER 1 THE ENHANCED MACHINE CONTROL 13 e stepper tbl contains the tool information such as which pocket contains which tool and the length and diameter for each tool e rs274ngc var contains variables specific to the RS 274 NGC dialect of NC code notably for setting the persistent numeric variables for the nine work coordinate systems We ll get into some of the details of these files as we begin to hook up and operate our little machine In addition
60. get executed when the standard_pinout hal gets executed interpreted The Parport driver gets loaded see 8 1 for details The read amp write functions of the parport driver get assigned to the Base thread The step amp direction signals for axes X Y Z get linked to pins on the parport Further IO signals get connected estop loopback toolchanger loopback a gt O N e A spindle On signal gets defined and linked to a parport pin 4 3 3 Changing the standard_pinout hal If you want to change the standard_pinout hal file all you need is a text editor Open the file and locate the parts you want to change If you want for example to change the pin for the X axis Step amp Directions signals all you need to do is to change the number in the parport 0 pin XX out name linksp Xstep parport 0 pin 03 out linksp Xdir parport 0 pin 02 out can be changed to linksp Xstep parport 0 pin 02 out linksp Xdir parport 0 pin 03 out or basicly any other numbers you like Hint make sure you don t have more than one signal connected to the same pin 4 3 4 Changing the polarity of a signal If external hardware expects an active low signal set the corresponding invert parameter For instance to invert the spindle control signal setp parport 0 pin 0 invert TRUE 3the fastest thread in the EMC2 setup usually the code gets executed every few microseconds CHAPTER 4 BASIC CONFIGURATIONS FOR A ST
61. gt stepgen lt channel range gt setup tim Sets minimum time between direction change and step pulse in units of 100nS Applies to a group fof four consecutive PWM generators as indicated by lt channel range gt U32 ppmc lt port gt stepgen lt channel range gt pulse width Sets width of step pulses in units of 100nS Applies to a group fof four consecutive PWM generators as indicated by lt channel range gt U32 ppmc lt port gt stepgen lt channel range gt pulse space min Sets minimum time between pulses in units of 100nS The maximum step rate is 1 100nS pulse width pulse space min Applies to a group fof four consecutive PWM generators as indicated by lt channel range gt FLOAT ppmc lt port gt stepgen lt channel gt scale Scaling for step pulse generator The step frequency in Hz is the absolute value of velocity scale FLOAT ppmc lt port gt stepgen lt channel gt max vel The maximum value for velocity Commands greater than max vel will be clamped Also applies to negative values The absolute value is clamped FLOAT ppmc lt port gt stepgen lt channel gt frequency Actual step pulse frequency in Hz used mostly for troubleshooting BIT ppmc lt port gt out lt channel gt invert Inverts a digital output see canonical digital output 8 7 4 Functions e FUNCT ppmc lt port gt read Reads all inputs digital inputs and encoder counters on one por
62. halcmd start Although nothing appears to happen inside the computer the step pulse generator is cranking out step pulses varying from 10KHz forward to 10KHz reverse and back again every second Later in this tutorial we ll see how to bring those internal signals out to run motors in the real world but first we want to look at them and see what is happening 7 6 Taking a closer look with halscope The previous example generates some very interesting signals But much of what happens is far too fast to see with halmeter To take a closer look at what is going on inside the HAL we want an oscilloscope Fortunately HAL has one called halscope 7 6 1 Starting Halscope Halscope has two parts a realtime part that is loaded as a kernel module and a user part that supplies the GUI and display However you don t need to worry about this because the userspace portion will automatically request that the realtime part be loaded halcmd loadusr halscope CHAPTER 7 HAL TUTORIAL 65 The scope GUI window will open immediately followed by a Realtime function not linked dialog that looks like figure 7 4 MAA Realtime function not linked x The HALSCOPE realtime sampling function must be called from a HAL thread in to determine the sampling rate Please do one of the following Select a thread name and multiplier then click OK or Click Quit to exit HALSCOPE Thread Sample Period Sample Rate Thre
63. have different meanings in different contexts Table 13 1 Words and their meanings Letter Meaning A axis of machine B axis of machine C axis of machine Tool radius compensation number Feedrate General function See table 5 Tool length offset index X offset for arcs and G87 canned cycles Y offset for arcs and G87 canned cycles Z offset for arcs and G87 canned cycles Spindle Motion Ratio for G33 synchronized movements Miscellaneous function See table 7 Line number Dwell time in canned cycles and with G4 Key used with G10 Feed increment in G83 canned cycle Arc radius or canned cycle plane Spindle speed Tool selection X axis of machine Y axis of machine Z axis of machine AUS ao o ao a to gt oz N K KIH a WO CHAPTER 13 LANGUAGE OVERVIEW 132 13 3 1 Number The following rules are used for explicit numbers In these rules a digit is a single character between O and 9 e A number consists of 1 an optional plus or minus sign followed by 2 zero to many digits followed possibly by 3 one decimal point followed by 4 zero to many digits provided that there is at least one digit somewhere in the number e There are two kinds of numbers integers and decimals An integer does not have a decimal point in it a decimal does e Numbers may have any number of digits subject to the limitation on line length Only abo
64. in lt channel gt not Inverted state of digital input pin see canonical digital input BIT ppmc lt port gt out lt channel gt Value to be written to digital output seen canonical digital output 3 Parameters FLOAT ppmc lt port gt enc lt channel gt scale The number of counts user unit to convert from counts to units FLOAT ppmc lt port gt pwm lt channel range gt freq The PWM carrier frequency in Hz Applies to a group of four consecutive PWM generators as indicated by lt channel range gt Minimum is 153Hz maximum is 500KHz FLOAT ppmc lt port gt pwm lt channel gt scale Scaling for PWM generator If scale is X then the duty cycle will be 100 when the value pin is X or X FLOAT ppmc lt port gt pwm lt channel gt max dc Maximum duty cycle from 0 0 to 1 0 FLOAT ppmc lt port gt pwm lt channel gt min dc Minimum duty cycle from 0 0 to 1 0 FLOAT ppmc lt port gt pwm lt channel gt duty cycle Actual duty cycle used mostly for troubleshooting 14Index handling does _not_ comply with the canonical encoder interface and should be changed CHAPTER 8 HARDWARE DRIVERS 89 e BIT ppmc lt port gt pwm lt channel gt bootstrap If true the PWM generator will generate a short sequence of pulses of both polarities when it is enabled to charge the bootstrap capacators used on some MOSFET gate drivers U32 ppmc lt port
65. in a way that makes it easy for the operator to understand Perhaps the most important display is the mode the EMC2 is running in You will want to keep your eye on the mode display Right up there with knowing what mode is active is consistent display of the position of each axis Most of the interfaces will allow the operator to read position based upon actual or commanded position as well as machine or relative position CHAPTER 1 THE ENHANCED MACHINE CONTROL 11 Figure 1 7 EMC2 Process Diagram PC EMC Process overly Simplified GUT G CO DE iia ACH TkEric Servo to Go Card or a Printer Port Motion Control Routines Drivers for Axis Motors Motors m Servo or stepper Machine Leadscrews Axis le Actuators Machine This is the position of an axis relative to the place where it started or was homed Relative This is the position of an axis after work or tool or other offsets have been applied Actual This is the real position of the axis within the machine or relative system Commanded This is where the axis is commanded to be These may all be exactly the same if no offsets have been applied and there is no deadband set in the INI file Deadband is a small distance which is assumed to be close enough perhaps one stepper pulse or one encoder count It is also important to see any messages or error codes sent by the EMC2 These are used to request the operator change a tool to describe problems in G
66. is indicated by the tool cone The cone does not indicate anything about the shape length or radius of the tool When a tool is loaded for instance with the MDI command T1M6 the cone changes to a cylinder which shows the diameter of the tool given in the tool table file 9 3 2 5 Backplot When the machine moves it leaves a trail called the backplot The color of the line indicates the type of motion Yellow for jogs faint green for rapid movements red for straight moves at a feed rate and magenta for circular moves at a feed rate 9 3 2 6 Interacting with the display By left clicking on a portion of the preview plot the line will be highlighted in both the graphical and text displays By left clicking on an empty area the highlighting will be removed By dragging with the left mouse button pressed the preview plot will be shifted panned By dragging with shift and the left mouse button pressed or by dragging with the mouse wheel pressed the preview plot will be rotated When a line is highlighted the center of rotation is the center of the line Otherwise the center of rotation is the center of the file as a whole By rotating the mouse wheel or by dragging with the right mouse button pressed or by dragging with control and the left mouse button pressed the preview plot will be zoomed in or out By clicking one of the Preset View icons or by pressing V several preset views may be selected 9 3 3 Tex
67. is removed For instance if the HAL pin motion spindle brake is not connected then the Brake button will not appear on the screen If the environment variable AXIS_NO_AUTOCONFIGURE is set this behavior is disabled and all the items will appear 9 3 4 1 The Axis group Axis allows you to manually move the machine This action is known as jogging First select the axis to be moved by clicking it Then click and hold the or button depending on the desired direction of motion The first four axes can also be moved by the arrow keys X and Y PAGE UP and PAGE DOWN keys Z and the and keys A If Continuous is selected the motion will continue as long as the button or key is pressed If another value is selected the machine will move exactly the displayed distance each time the button is clicked or the key is pressed By default the available values are CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 96 0 1000 0 0100 0 0010 0 0001 The ini file setting DISPLAY INCREMENTS can be used to override the default Its value can contain decimal numbers e g 0 1000 or fractional numbers e g 1 16 For machines configured as metric a good setting might be INCREMENTS 1 0 1 0 01 0 001 For a machine configured as imperial inches a good setting might be INCREMENTS 1 8 1 1 16 1 32 01 0 001 0 0001 If your machine has a homing sequence defined
68. it may be zero which is not a slot number If it is zero the value of the radius will also be zero Any slot in the tool table may be selected this way The D number does not have to be the same as the slot number of the tool in the spindle Tool Table Cutter radius compensation uses data from the machining center s tool table For each slot in the tool carrousel the tool table contains the diameter of the tool in that slot or the difference between the actual diameter of the tool in the slot and its nominal value The tool table is indexed by slot number How to put data into the table when using the stand alone interpreter is discussed in the tool table page Two Kinds of Contour The interpreter handles compensation for two types of contour e The contour given in the NC code is the edge of material that is not to be machined away We will call this type a material edge contour e The contour given in the NC code is the tool path that would be followed by a tool of exactly the correct radius We will call this type a tool path contour The interpreter does not have any setting that determines which type of contour is used but the description of the contour will differ for the same part geometry between the two types and the values for diameters in the tool table will be different for the two types Material Edge Contour When the contour is the edge of the material the outline of the edge is described in the NC program F
69. it with the menu system and file browser on Ubuntu systems e From the Places Menu choose Computer e click Filesystem e click etc e click emc2 e click sample configs You will see a number of sample configurations with names like sim stepper motenc etc These are the ones that you ve been looking at with the Conifguration Selector You can copy any of them to use as the beginning of your customized configuration You should pick one that is close to what you ultimately need For instance if your machine uses stepper motors you probably should CHAPTER 3 RUNNING EMC2 20 choose the stepper configuration Ifyou are using servos with a Servo to Go card stg is for you Move your mouse cursor over the configuration directory you wish to copy right click it and choose copy Now we need to create a couple of directories in your home folder e From the Places Menu choose Home Folder e From File choose Create Folder e Enter the name emc2 where untitled folder is highlighted e click the new emc2 folder e From File choose Create Folder e Enter the name configs where untitled folder is highlighted double click the new configs folder right click in the empty space in that folder and choose paste Start EMC2 from the menu The Configuration Selector will show you your new configuration at the top of the Tree Press the Cancel button to go back to the file browser that you used to c
70. jumpers on the baord so it may be non zero even if there is only one board 8 7 s32 ppmc lt port gt encoder lt channel gt count Encoder position in counts s32 ppmc lt port gt encoder lt channel gt delta Change in counts since last read FLOAT ppmc lt port gt encoder lt channel gt position Encoder position in user units BIT ppmc lt port gt encoder lt channel gt index Something to do with index pulse BIT ppmc lt port gt pwm lt channel gt enable Enables a PWM generator FLOAT ppmc lt port gt pwm lt channel gt value Value which determines the duty cycle of the PWM waveforms The value is divided by pwm lt channel gt scale and if the result is 0 6 the duty cycle will be 60 and so on Negative values result in the duty cycle being based on the absolute value and the direction pin is set to indicate negative BIT ppmc lt port gt stepgen lt channel gt enable Enables a step pulse generator FLOAT ppmc lt port gt stepgen lt channel gt velocity Value which determines the step frequency The value is multiplied by stepgen lt channel gt scale and the result is the frequency in steps per second Negative values result in the frequency being based on the absolute value and the direction pin is set to indicate negative BIT ppmc lt port gt in lt channel gt State of digital input pin see canonical digital input BIT ppmc lt port gt
71. move to the predefined position If no axis words are programmed the intermediate point is the current point so only one move is made G28 and G30 do not use home switches to find the predefined position They merely command a rapid motion to the position defined by the parameters assuming that the machine has already been homed 14 10 G38 2 Straight Probe Program G38 2 X Y Z A B C to perform a straight probe operation The axis words are optional except that at least one of them must be used The tool in the spindle must be a probe It is an error if e the current point is the same as the programmed point e no axis word is used e cutter radius compensation is enabled e the feed rate is zero In response to this command the machine moves the controlled point which should be at the end of the probe tip in a straight line at the current feed rate toward the programmed point In inverse time feed mode the feed rate is such that the whole motion from the current point to the programmed point would take the specified time If the probe does not trip during the move an error is signalled After successful probing parameters 5061 to 5066 will be set to the coordinates of the location of the controlled point at the time the probe tripped A comment of the form PROBEOPEN filename txt will open filename txt and store the coordinate of each successful straight probe in it The file must be closed with PROBECLOSE
72. number G code pairs are 1 G54 2 G55 3 G56 4 G57 5 G58 6 G59 7 G59 1 8 G59 2 and 9 G59 3 It is an error if e one of these G codes is used while cutter radius compensation is on See Section 12 6 for an overview of coordinate systems CHAPTER 14 G CODES 142 14 15 G61 G61 1 G64 Set Path Control Mode Program G61 to put the machining center into exact path mode G61 1 for exact stop mode or G64 P for continuous mode with optional tolerance It is OK to program for the mode that is already active See Section 12 2 15 for a discussion of these modes 14 16 G80 Cancel Modal Motion Program G80 to ensure no axis motion will occur It is an error if e Axis words are programmed when G80 is active unless a modal group O G code is programmed which uses axis words 14 17 G76 Threading Canned Cycle Program G76 P Z I J R K Q H to perform a threading canned cycle It is an error if e The active plane is not the ZX plane e Other axis words such as X or Y are specified e The R degression value is less than 1 0 e All the required words are not specified e J K or H is negative The drive line is a safe line outside the thread material The drive line goes from the initial location to the Z value specified with G76 The Z extent of the thread is the same as the drive line The thread pitch or distance per revolution is given by the P value The thread peak
73. of table movement Let s assume instead that we have a 5 turn per inch leadscrew connected to a 200 step per rev stepper with 10x microstepping So it takes 2000 steps for one revolution of the screw and 5 revolutions to travel one inch that means the overall scaling is 10000 steps per inch We need to multiply the velocity input to the step pulse generator by 10000 to get the proper output That is exactly what the parameter freggen n velocity scale is for In this case both the X and Y axis have the same scaling so we set the scaling parameters for both to 10000 halcmd setp freqgen 0 velocity scale 10000 halcmd setp freqgen 1 velocity scale 10000 This velocity scaling means that when the pin freqgen 0 velocity is 1 000 the step generator will generate 10000 pulses per second 10KHz With the motor and leadscrew described above that will result in the axis moving at exactly 1 000 inches per second This illustrates a key HAL concept things like scaling are done at the lowest possible level in this case in the step pulse generator The internal signal X_vel is the velocity of the table in inches per second and other components such as siggen don t know or care about the scaling at all If we changed the leadscrew or motor we would change only the scaling parameter of the step pulse generator 7 5 5 Run it We now have everything configured and are ready to start it up Just like in the first example we use the start command
74. of the circle J and K are optional except that at least one of the two must be used It is an error if e Y and Z are both omitted e or J and K are both omitted Here is an example of a center format command to mill an arc G17 G2 x10 y16 13 34 z9 That means to make a clockwise as viewed from the positive z axis circular or helical arc whose axis is parallel to the Z axis ending where X 10 Y 16 and Z 9 with its center offset in the X direction by 3 units from the current X location and offset in the Y direction by 4 units from the current Y location If the current location has X 7 Y 7 at the outset the center will be at X 10 Y 11 If the starting value of Z is 9 this is a circular arc otherwise it is a helical arc The radius of this are would be 5 In the center format the radius of the arc is not specified but it may be found easily as the distance from the center of the circle to either the current point or the end point of the arc 14 4 G33 Spindle Synchronized Motion For spindle synchronized motion code G33 X Y Z K where K gives the distance moved in XYZ for each revolution of the spindle This syntax is subject to change In particular to use F instead of K For instance G33 Z1 K 0625 produces a 1 inch motion in Z over 16 revolutions of the spindle This command might be part of a program to produce a 16TPI thread All the axis words are optional except that at least one must be used This will produce coordin
75. of the three linear motion mechanisms are expressed using coordinates on these axes 12 2 2 Rotational Axes The rotational axes are measured in degrees as wrapped linear axes in which the direction of positive rotation is counterclockwise when viewed from the positive end of the corresponding X Y or Z axis By wrapped linear axis we mean one on which the angular position increases without limit goes towards plus infinity as the axis turns counterclockwise and deceases without limit goes towards minus infinity as the axis turns clockwise Wrapped linear axes are used regardless of whether or not there is a mechanical limit on rotation Clockwise or counterclockwise is from the point of view of the workpiece If the workpiece is fastened to a turntable which turns on a rotational axis a counterclockwise turn from the point of view of the workpiece is accomplished by turning the turntable in a direction that for most common machine configurations looks clockwise from the point of view of someone standing next to the machine 12 2 3 Controlled Point The controlled point is the point whose position and rate of motion are controlled When the tool length offset is zero the default value this is a point on the spindle axis often called the gauge point that is some fixed distance beyond the end of the spindle usually near the end of a tool holder that fits into the spindle The location of the controlled point can be moved out along th
76. or CNC is the general term used to name this kind of computer application In order to get right into the essential task of operating it we have limited the amount of information about installation and setup We assume that the user will install one of the standard ways covered in Chapter 2 Machine wiring and setup is limited to what we refer to as a mini or benchtop mill that is powered by stepper motors and amps that use a single parallel port If the user is interested in developing their own install using some other distribution of Linux or another operating system or applying the EMC2 to a more complex machine they should study the Integrators Handbook where these topics are covered in greater detail 1 2 The Big CNC Picture The term CNC has taken on a lot of different meanings over the years In the early days CNC replaced the hands of a skilled machinist with motors that followed commands in much the same way that the machinist turned the handwheels From these early machines a language of machine tool control has grown This language is called RS274 and several standard variants of it have been put forward It has also been expanded by machine tool and control builders in order to meet the needs of specific machines If a machine changed tools during a program it needed to have tool change commands If it changed pallets in order to load new castings it had to have commands that allowed for these kinds of devices as well Like any languag
77. outputs The Motenc LITE has only 4 encoder counters 32 digital inputs and 16 digital outputs but it still has 8 analog inputs and 8 analog outputs The driver automatically identifies the installed board and exports the appropriate HAL objects Installing lSIdeally the encoders DACs ADCs and digital I O would comply with the canonical interfaces defined earlier but they don t Fixing that is on the things to do list CHAPTER 8 HARDWARE DRIVERS 86 emc2S halcmd loadrt hal_motenc During loading or attempted loading the driver prints some usefull debugging message to the kernel log which can be viewed with dmesg 8 6 1 Removing emc2S halcmd unloadrt hal_motenc 8 6 2 Pins In the following pins parameters and functions lt board gt is the board ID According to the naming conventions the first board should always have an ID of zero However this driver sets the ID based on a pair of jumpers on the baord so it may be non zero even if there is only one board e s32 motenc lt board gt enc lt channel gt count Encoder position in counts e FLOAT motenc lt board gt enc lt channel gt position Encoder position in user units e BIT motenc lt board gt enc lt channel gt index Current status of index pulse input e BIT motenc lt board gt enc lt channel gt idx latch Driver sets this pin true when it latches an index pulse enabled by lat ch index Cleared by clearing latch index
78. parport lt portnum gt pin lt pinnum gt in Tracks a physical input pin e BIT parport lt portnum gt pin lt pinnum gt in not Tracks a physical input pin but inverted For each pin lt portnum gt is the port number and lt pinnum gt is the physical pin number in the 25 pin D shell connector For each physical output pin the driver creates a single HAL pin for example parport 0 pin 14 out Pins 1 14 16 and 17 are always outputs Pins 2 through 9 are part of the data group and are output pins if the port is defined as an output port Output is the default These HAL pins control the state of the corresponding physical pins For each physical input pin the driver creates two HAL pins for example parport 0 pin 12 in and parport 0 pin 12 in not Pins 10 11 12 13 and 15 are always input pins Pins 2 through 9 are input pins only if the port is defined as an input port The in HAL pin is TRUE if the physical pin is high and FALSE if the physical pin is low The in not HAL pin is inverted it is FALSE if the physical pin is high By connecting a signal to one or the other the user can determine the state of the input 8 1 4 Parameters e BIT parport lt portnum gt pin lt pinnum gt out invert Inverts an output pin The invert parameter determines whether an output pin is active high or active low If invert is FALSE setting the HAL out pin TRUE drives the physical pin high and FALSE drives it low
79. plane to the position that axis was in just before the canned cycle started unless that position is lower than the position indicated by the R word in which case use the R word position To use option 1 program G99 To use option 2 program G98 Remember that the R word has different meanings in absolute distance mode and incremental distance mode Chapter 15 M Codes 15 1 MO M1 M2 M30 M60 Program Stopping and Ending To stop a running program temporarily regardless of the setting of the optional stop switch pro gram MO To stop a running program temporarily but only if the optional stop switch is on program Ml It is OK to program MO and M1 in MDI mode but the effect will probably not be noticeable because normal behavior in MDI mode is to stop after each line of input anyway To exchange pallet shuttles and then stop a running program temporarily regardless of the setting of the optional stop switch program M60 If a program is stopped by an MO M1 or M60 pressing the cycle start button will restart the program at the following line To end a program program M2 To exchange pallet shuttles and then end a program program M30 Both of these commands have the following effects Eu Axis offsets are set to zero like G92 2 and origin offsets are set to the default like G54 Selected plane is set to CANON_PLANE_XY like G17 Distance mode is set to MODE_ABSOLUTE like G90 Feed rate mode is
80. r manual newsig homeswitches bit linkp s parport 0 pin 10 in gt homeswitches linksp homeswitches gt axis 0 home sw in linksp homeswitches gt axis 1 home sw in linksp homeswitches gt axis 2 home sw in Sample separate limit switches on the X axis axis 0 newsig X neg limit bit linkp s parport 0 pin 11 in gt X neg limit linksp X neg limit gt axis 0 neg 1lim sw in newsig X pos limit bit linkp s parport 0 pin 12 in gt X pos limit linksp X pos limit gt axis 0 pos lim sw in Just like the shared home switches example you can wire together limit switches Beware if you hit one EMC will stop but can t tell which switch axis has faulted Use caution when recovering from this linkps parport pin 13 in gt Xlimits CHAPTER 4 BASIC CONFIGURATIONS FOR A STEPPER BASED SYSTEM 26 linksp Xlimits gt axis 0 neg lim sw in linksp Xlimits gt axis 0 pos lim sw in you Can also use the net syntax to accomplish the newsig and link operations all at once This command does the same thing as the above block net Xlimits parport pin 13 in gt axis 0 neg lim sw in axis 0 pos lim sw in The files starting with are comments and their only purpose is to guide the reader through the file 4 3 2 Overview of the standard_pinout hal There are a couple of operations that
81. rate is active during a canned cycle e or cutter radius compensation is active during a canned cycle When the XY plane is active the Z number is sticky and it is an error if e the Z number is missing and the same canned cycle was not already active e or the R number is less than the Z number When the XZ plane is active the Y number is sticky and it is an error if e the Y number is missing and the same canned cycle was not already active e or the R number is less than the Y number When the YZ plane is active the X number is sticky and it is an error if e the X number is missing and the same canned cycle was not already active e or the R number is less than the X number CHAPTER 14 G CODES 145 14 18 1 Preliminary and In Between Motion At the very beginning of the execution of any of the canned cycles with the XY plane selected if the current Z position is below the R position the Z axis is traversed to the R position This happens only once regardless of the value of L In addition at the beginning of the first cycle and each repeat the following one or two moves are made 1 a straight traverse parallel to the XY plane to the given XY position 2 a straight traverse of the Z axis only to the R position ifit is not already at the R position If the XZ or YZ plane is active the preliminary and in between motions are analogous 14 18 2 G81 Drilling Cycle The G81 cycle is intended for drilling Pro
82. required 8 2 probe parport In modern PCs the parallel port may require plug and play PNP configuration before it can be used The probe_parport module performs configuration of any PNP ports present and should be loaded before hal_parport On machines without PNP ports it cannot be loaded 8 2 1 Installing loadrt probe _parport loadrt hal_parport If the Linux kernel prints a message similar to parport PnPBIOS parport detected when the parport_pc module is loaded sudo modprobe a parport_pc then use of this module is probably required 8 3 AX5214H The Axiom Measurement amp Control AX5214H is a 48 channel digital I O board It plugs into a PCI bus and resembles a pair of 8255 chips 3In fact it may be a pair of 8255 chips but I m not sure If when someone starts a driver for an 8255 they should look at the ax5214 code much of the work is already done CHAPTER 8 HARDWARE DRIVERS 78 8 3 1 Installing From command line emc2 halcmd loadrt hal_ax5214h cfg lt config string gt From a file loadrt hal_ax5214h cfg lt config string gt The config string consists of a hex port address followed by an 8 character string of I and O which sets groups of pins as inputs and outputs The first two character set the direction of the first two 8 bit blocks of pins 0 7 and 8 15 The next two set blocks of 4 pins 16 19 and 20 23 The pattern then repeats two more blocks of 8 bits 24 31 and 32
83. section of the screen upper right Since we have a 4000 sample record length and are acquiring 1000 samples per second it will take halscope about 2 seconds to fill half of its buffer During that time a progress bar just above the main screen will show the buffer filling Once the buffer is half full the scope waits for a trigger Since we haven t configured one yet it will wait forever To manually trigger it click the Force button in the Trigger section at the top right You should see the remainder of the buffer fill then the screen will display the captured waveforms The result will look something like figure 7 7 X A HAL Oscilliscope mak Horizontal Run Mode Trigger Zoom 500 mSec 4047 samples Normal e Normal Pos per div at 994 Hz C Single C Auto SaaS TRIGGER C stop Force Vertical Level Pos Gain Pos ovens OR a o tun a Scale Level 1 div Te shonldrrrle ore _ en Selected Channel 0 000 4 siggen 1 square Chan Off Source None Figure 7 7 Captured Waveforms The Selected Channel box at the bottom tells you that the green trace is the currently selected one channel 4 which is displaying the value of the pin siggen 1 square Try clicking channel buttons 1 through 3 to highlight the other three traces CHAPTER 7 HAL TUTORIAL 69 7 6 4 Vertical Adjustments The traces are rather hard
84. servo amp what kind of limit switches and how many etc The integrator s decisions about which specific components to use is based on what that component does and the specifications supplied by the manufacturer of the device The size of a motor and the load it must drive will affect the choice of amplifier needed to run it The choice of amplifier may affect the kinds of feedback needed by the amp and the velocity or position signals that must be sent to the amp from a control In the HAL world the integrator must decide what HAL components are needed Usually every interface card will require a driver Additional components may be needed for software generation of step pulses PLC functionality and a wide variety of other tasks 6 1 1 2 Interconnection Design The designer of a hardware system not only selects the parts he also decides how those parts will be interconnected Each black box has terminals perhaps only two for a simple switch or dozens 43 CHAPTER 6 INTRODUCTION 44 for a servo drive or PLC They need to be wired together The motors connect to the servo amps the limit switches connect to the controller and so on As the machine builder works on the design he creates a large wiring diagram that shows how all the parts should be interconnected When using HAL components are interconnected by signals The designer must decide which signals are needed and what they should connect 6 1 1 3 Implementation Once the
85. set to UNITS_PER_MINUTE like G94 Feed and speed overrides are set to ON like M48 Cutter compensation is turned off like G40 The spindle is stopped like M5 The current motion mode is set to G_1 like G1 O 0 XA O 0d Pp WwW DN Coolant is turned off like M9 No more lines of code in an RS274 NGC file will be executed after the M2 or M30 command is executed Pressing cycle start will start the program back at the beginning of the file 150 CHAPTER 15 MCODES 151 15 2 M3 M4 M5 Spindle Control To start the spindle turning clockwise at the currently programmed speed program M3 To start the spindle turning counterclockwise at the currently programmed speed program M4 To stop the spindle from turning program M5 It is OK to use M3 or M4 if the spindle speed is set to zero If this is done or if the speed override switch is enabled and set to zero the spindle will not start turning If later the spindle speed is set above zero or the override switch is turned up the spindle will start turning It is OK to use M3 or M4 when the spindle is already turning or to use M5 when the spindle is already stopped 15 3 M6 Tool Change To change a tool in the spindle from the tool currently in the spindle to the tool most recently selected using a T word see Section 17 3 program M6 When the tool change is complete The spindle will be stopped The tool that was selected by a T word on the same line
86. the HAL As it is described in the HAL Introduction and tutorial we have signals pins and parameters inside the HAL The ones relevant for our pinout are Signals Xstep Xdir amp Xen pins parport 0 pin XX out parport 0 pin XX in A Depending on what you have chosen in your ini file you are using either standard_pinout hal or xylotex_pinout hal These are two files that instruct the HAL how to link the various signals amp pins Furtheron we ll investigate the standard_pinout hal 4 3 1 standard_pinout hal This file contains several HAL commands and usually looks like this standard pinout config file for 3 axis steppers using a parport for I O first load the parport driver loadrt hal_parport cfg 0x0378 next connect the parport functions to threads read inputs first addf parport 0 read base thread 1 write outputs last addf parport 0 write base thread 1 finally connect physical pins to the signals linksp Xstep gt parport 0 pin 03 out linksp Xdir gt parport 0 pin 02 out linksp Ystep gt parport 0 pin 05 out linksp Ydir gt parport 0 pin 04 out linksp Zstep gt parport 0 pin 07 out linksp Zdir gt parport 0 pin 06 out create a signal for the estop loopback linkpp iocontrol 0 user enable out iocontrol 0 emc enable in create signals for tool loading loopback linkpp iocontrol 0 tool prepare iocontrol 0 tool prepared linkpp iocontrol 0 tool change iocontrol
87. the end of the move Most RS274 NGC commands start with either G or M for General and Miscellaneous The words for these commands are called G codes and M codes The RS274 NGC language has no indicator for the start of a program The Interpreter however deals with files A single program may be in a single file or a program may be spread across several files A file may demarcated with percents in the following way The first non blank line of a file may contain nothing but a percent sign possibly surrounded by white space and later in the file normally at the end of the file there may be a similar line Demarcating a file with percents is optional if the file has an M2 or M30 in it but is required if not An error will be signalled if a file has a percent line at the beginning but not at the end The useful contents of a file demarcated by percents stop after the second percent line Anything after that is ignored The RS274 NGC language has two commands M2 or M30 either of which ends a program A program may end before the end of a file Lines of a file that occur after the end of a program are not to be executed The interpreter does not even read them 13 1 Format of a line A permissible line of input RS274 NGC code consists of the following in order with the restriction that there is a maximum currently 256 to the number of characters allowed on a line 1 an optional block delete character which is a sl
88. toggled individually using M50 and M51 as described in the sections 15 6 and 15 7 CHAPTER 15 MCODES 152 15 6 M50 Feed Override Control To enable the feedrate override switch program M50 or M50 P1 To disable the switch program M50 PO While disabled the feed override will have no influence and the motion will be executed at programmed feedrate unless there is an adaptive feedrate override active 15 7 M51 Spindle Speed Override Control To enable the spindle speed override switch program M51 or M51 P1 To disable the switch program M51 PO While disabled the spindle speed override will have no influence and the spindle speed will have the exact program specified value using the S word as described in 17 2 15 8 M52 Adaptive Feed Control To use an adaptive feed program M52 or M52 P1 To stop using adaptive feed program M52 PO When adaptive feed is enabled some external input value is used together with the user interface feed override value and the commanded feed rate to set the actual feed rate In EMC2 the HAL pin motion adaptive feed is used for this purpose Values on motion adaptive feed should range from O feed hold to 1 full speed 15 9 M53 Feed Stop Control To enable the feed stop switch program M53 or M53 P1 To disable the switch program M53 PO Enabling the feed stop switch will allow motion to be interrupted by means of the feedstop control In EMC2 the HAL pin motion feed hold is used for this purpose
89. tool offset works in a specific situation These references are intended to give the reader a sense of sequence rather than requiring the reader to understand the way that cannonical functions themselves work within the EMC 20 3 Tool Length Offsets Tool length offsets are given as positive numbers in the tool table A tool length offset is programmed using G43 Hn where n is the desired table index It is expected that all entries in the tool table will be positive The H number is checked for being a non negative integer when it is read The interpreter behaves as follows 1 If G43 Hn is programmed A USE_TOOL_LENGTH_OFFSET length function call is made where length is the value of the tool length offset entry in the tool table whose index is n tool_length_offset is reset in the machine settings model and the value of current_z in the model is adjusted Note that n does not have to be the same as the slot number of the tool currently in the spindle 2 If G49 is programmed USE_TOOL_LENGTH_OFFSET 0 0 is called tool_length_offset is reset to 0 0 in the machine settings model and the value of current_z in the model is adjusted The effect of tool length compensation is illustrated in the screen shot below Notice that the length of the tool is subtracted from the z setting so that the tool tip appears at the programmed setting a You should note that the effect of tool length compensation is immediate when you view the z position as a relative
90. top of tool path 0050 G1 Y 1 cut along right side of tool path 0060 G2 X2 Y 1 5 I 0 5 cut along arc at bottom right of tool path 0070 Gl X 2 cut along bottom side of tool path 0080 G2 X 2 3 Y 0 6 J0 5 cut along arc at bottom left of tool path 0090 G1 X1 7 Y2 4 cut along hypotenuse of tool path 0100 G2 X2 Y2 5 10 3 J 0 4 cut along arc at top of tool path 0110 G40 turn compensation off This will result in the tool making an alignment move and two entry moves and then following a path slightly inside the path shown on the left in Figure 7 going clockwise around the triangle This path is to the right of the programmed path even though G41 was programmed because the diameter value is negative Programming Errors and Limitations The interpreter will issue the following messages involving cutter radius compensation Eu Cannot change axis offsets with cutter radius comp 2 Cannot change units with cutter radius comp 3 Cannot turn cutter radius comp on out of XY plane 4 Cannot turn cutter radius comp on when already on CHAPTER 20 TOOL FILE AND COMPENSATION 165 Cannot use G28 or G30 with cutter radius comp Cannot use G53 with cutter radius comp Cannot use XZ plane with cutter radius comp Cannot use YZ plane with cutter radius comp O ON Q A Concave corner with cutter radius comp 10 Cutter gouging with cutter radius comp 11 D word on line with no cutter comp on G41 or G42 command 12 Tool ra
91. turn on rapid traverse and move to coordinate home The advantage of the first set is that the G80 line clearly turns off the G81 canned cycle With the first set of blocks the programmer must turn motion back on with GO as is done in the next line or any other motion mode G word Example 1 Use of a canned cycle as a modal motion code If a canned cycle is not turned off with G80 or another motion word the canned cycle will attempt to repeat itself using the next block of code that contains an X Y or Z word The following file drills G81 a set of eight holes as shown note the z position change after the first four holes N100 G90 GO X0 YO Z0 coordinate home N110 G1 X0 G4 P0 1 3D PLOT N120 G81 X1 YO Z0 R1 canned drill cycle z Absolute distance mode N130 x2 G81 drilling cycle R valve aber N140 X3 Second Z value Nee G80 tums off a N160 Y1 20 5 G81 here N170 X3 N180 X2 G81 canned cycle z __ First Z value N190 X1 starts here aS N200 G80 turn off canned cycle Yea Se N210 GO X0 rapid home moves 0 0 0 Preliminary move to R value N220 Y0 N220 ZO N220 M2 program end The use of G80 in line n200 is optional because the GO on the next line will turn off the G81 cycle But using the G80 as example 1 shows will provide for an easily readable canned cycle Without it it is not so obvious that all of the blocks between N120 and N200 belong to the canned cycle If you use G80 and do not set a
92. var file provide a set of numbered variables for use by the interpreter These values are saved from one run to another TBL The tbl file saves tool information NML The nml file configures the communication channels used by the EMC It is normally setup to run all of the communication within a single computer but can be modified to communicate between several computers emerc This file saves user specific information and is created to save the name of the directory when the user first selects an EMC configuration This chapter describes the EMC2 s INI file in just enough detail so that the reader can understand which variable values might need to be edited in order to make a stock configuration conform to a real machine 5 2 The INI File Layout A typical INI file follows a rather simple layout that includes 1Don t confuse a text editor with a word processor A text editor like gedit or kwrite produce files that are plain text They also produce lines of text that are separated from each other A word processor like Open Office produce files with paragraphs and word wrapping and lots of embedded codes that control font size and such A text editor does none of this 2Usually this file is in the users home directory e g home user Complete reference to these files are left to the Integrator and Developer Handbooks 28 CHAPTER 5 INI CONFIGURATION 29 e comments e sections e variables Each of these elements is
93. was going It is unclear how the operator is to manually move the tool because a change to manual mode resets the program to the top We will attempt to clarify that step in this procedure 22 11 G89 Cycle The G89 cycle is intended for boring This cycle uses a P value where P specifies the number of seconds to dwell O Preliminary motion as described above 1 Move the Z axis only at the current feed rate to the Z position 2 Dwell for the given number of seconds 3 Retract the Z axis at the current feed rate to clear Z This cycle is like G82 except that the tool is drawn back at feedrate rather than rapid 22 12 G98 G99 G98 initial level return in canned cycles G99 R value return in canned cycles These codes are treated together because they behave very much alike aYou will recall that when Z is above R the preparatory move is from the current location to the X Y values If G98 is not specified then the canned cycle will return to the R value rather than the Z value that was used on the approach CHAPTER 22 CANNED CYCLES 186 Default or G99 return NO1 GO X1 Y2 Z3 NO2 G90 G81 X4 Y5 Z 0 6 R1 8 Adding G98 to the second line above means that the return move will be to the value of OLD_Z since it is higher that the R value specified H Return position when Old Z is gt R Neither code will have any affect when incremental moves with a positive R value are specified because the R value is added to OLD_Z an
94. x 0 5 offsets g56 x value by 0 5 inch G10 L2 P4 y0 5 offsets g57 y value by 0 5 inch G10 L2 P5 y 0 5 offsets g58 y value by 0 5 inch We put these together in the following program a program for milling five small circles in a diamond shape G10 L2 P1 x0 yO ZO ensure that g54 is machine zero G10 L2 P2 x0 5 offsets g55 x value by 0 5 inch G10 L2 P3 x 0 5 offsets g56 x value by 0 5 inch G10 L2 P4 y0 5 offsets g57 y value by 0 5 inch G10 L2 P5 y 0 5 offsets g58 y value by 0 5 inch g54 gO x 1 yO z0 center circle gl fl z 25 g3 x 1 y0i 1j0 gO zO g55 gO x 1 yO ZO first offset circle gl fl z 25 g3 x 1 yOi 1 jo gO zO g56 gO x 1 yO zO second offset circle gl fl z 25 g3 x 1 yOi 1 jo gO zO g57 gO x 1 yO zO third offset circle gl fl z 25 g3 x 1 yOi 1 jo gO zO g58 gO x 1 yO zO fourth offset circle gl fl z 25 g3 x 1 yOi 1 jo g54 gO x0 yO zO m2 Now comes the time when we might apply a set of G92 offsets to this program You ll see that it is running in each case at z0 If the mill were at the zero position a g92 z1 0000 issued at the head of the program would shift everything down an inch You might also shift the whole pattern around in the XY plane by adding some x and y offsets with g92 If you do this you should add a G92 1 command just before the m2 that ends the program If you do not other programs that you might run after this one will also use that g92 offset Furthermore i
95. 0000e 00 Y vel The next step is to connect the signals to component pins The signal X_vel is intended to run from the cosine output of the signal generator to the velocity input of the first step pulse generator The first step is to connect the signal to the signal generator output To connect a signal to a pin we use the 1inksp command halcmd linksp X_vel siggen 0 cosine To see the effect of the 1inksp command we show the signals again CHAPTER 7 HAL TUTORIAL 62 halcmd show sig ignals Type Value Name float 0 00000e 00 X_vel lt siggen 0 cosine float 0 00000e 00 Y vel When a signal is connected to one or more pins the show command lists the pins immediately following the signal name The arrow shows the direction of data flow in this case data flows from pin siggen 0 cosine to signal X_vel Now let s connect the X_vel to the velocity input of a step pulse generator halcmd linksp X_vel freqgen 0 velocity We can also connect up the Y axis signal Y_vel It is intended to run from the sine output of the signal generator to the input of the second step pulse generator halcmd linksp Y vel siggen 0 sine halcmd linksp Y vel freqgen 1 velocity Now let s take a final look at the signals and the pins connected to them halcmd show sig Signals Type Value Name float 0 00000e 00 X_vel lt siggen 0 cosine gt freqgen 0 velocity float 0 00000e 00 Y vel lt siggen 0 sine
96. 03 X0 8225 Y3 3307 RO 3 0 0 0 N G02 X2 9728 Y4 3563 R2 1875 G01 X7 212 Y3 7986 G02 X8 1985 Y3 2849 R1 625 0 G03 X8 4197 Y3 1875 RO 3 100 G01 X9 110 G40 X10 1972 Y3 432 COMP LEAD OUT 220 M02 Line 15 contains G41 D4 which means that the diameter of the tool described as tool 4 in the tool table will be used to offset the spindle by 1 2 the diameter which is of course the tool s radius Note that the line with the G41 command contains the endpoint of the move where the radius compensation is interpolated in What this means is that at the beginning of this move there is no compensation in effect and at the end the tool is offset by 100 of the selected tool radius Immediately after the G41 is D4 meaning that the offset is by the radius of tool number 4 in the tool table Note that tool DIAMETERS are entered in the tool table Jon s tool diameter is about 0 4890 But note that in line 110 where the G40 cancel cutter compensation command is that cutter compensation will be interpolated out in this move The way I have these set up the moves in lines 15 and 110 are almost exactly parallel to the X axis and the difference in Y coordinates is to line the tool up outside the portion of the program where cutter compensation is in force 1 2 4 5 6 7 8 9 Zz X PLOT Path of center of tool Direction of cut IM Offset lead Offset lead in move ES Actual part outline han of oe of cut In
97. 1 0 96 9 9 87 10 10 87 STEPGEN_MAXVEL 1 4 A value applied to the stepper pulse generator to provide some overhead for following error catch up STEPGEN_MAXACCEL 21 0 Overhead for the stepper pulse generator when it needs to catch up 5 3 8 EMCIO Section CYCLE_TIME 0 100 The period in seconds at which EMCIO will run You can make this as small as you want to increase the throughput Making it 0 0 or a negative number will tell EMCIO not to sleep at all Ultimately the system loading will limit the effective throughput TOOL_TABLE tool tbl The file which contains tool information described in 12 4 TOOL_CHANGE_POSITION 0 O 2 Specifies the XYZ location to move to when performing a tool change 7The step generator module stepgen applies its own limits to acceleration and velocity We have discovered that it needs to have a little headroom over the accel by the trajectory planner otherwise it can fall slightly behind during accel and later overshoot as it catches up In the long term we hope to come up with a clean fix for this problem In the meantime please set STEPGEN_MAXVEL to a few percent higher than MAX VELOCITY the regular velocity limit and STEPGEN_MAXACCEL slightly larger that of MAX_ACCELERATION CHAPTER 5 INI CONFIGURATION 37 CHAPTER 5 INI CONFIGURATION 38 5 4 Homing 5 4 1 Overview Homing seems simple enough just move each joint to a known location and set EMC s internal va
98. 2 13 Why use a canned Cycle o coo oara aa ee E aoa ee ea els 186 CONTENTS 23 Image to gcode Milling depth maps 23 23 2 23 3 23 4 1 What is a depth map 23 4 1 23 4 2 23 4 3 23 4 4 23 4 5 23 4 6 23 4 7 23 4 8 23 4 9 23 4 10 23 4 11 23 4 12 23 4 13 23 4 14 23 4 15 23 4 16 23 4 17 Using image to gcode Option Reference MUG o a a O aa ee O eh al Sak TOWER AB oaia eai Se se eho ER A RE i Normal HABE csa oe eR HE EHS SEE Tolerance anit oia cia daa a HE AS Pixel Size mits coria a aa OE eS Plunge Feed Rate units per minute Feed Rate units perminute ppindie Speed RPM oc coso a ye meat POUR AN Scan Direttori e so be a a we a E a Depih UNIS es cassan A RA Hes Step Over Pixels corria ss ac a oR a aia Tool Diameter ak oco na tesa a we a A Glossary of Common Terms Used in the EMC Documents B Legal Section B 1 GNU Free Documentation License Version 1 1 March 2000 B 1 1 GNU Free Documentation License Version 1 1 March 2000 xiii 188 188 188 189 189 189 189 189 189 189 190 190 190 190 190 190 190 190 191 191 191 191 192 Part 1 Introduction amp installing EMC2 Chapter 1 The Enhanced Machine Control 1 1 Introduction This book is intended for people who want to use the Enhanced Machine Controller to run a mill lathe router or to control some other rather standard kind of machine Computer Numerical Control
99. 2 Pl x 3 5 y 17 2 sets the origin of the first coordinate system the one selected by G54 to a point where X is 3 5 and Y is 17 2 in absolute coordinates The Z coordinate of the origin and the coordinates for any rotational axes are whatever those coordinates of the origin were before the line was executed 14 7 G17 G18 G19 Plane Selection Program G17 to select the XY plane G18 to select the XZ plane or G19 to select the YZ plane The effects of having a plane selected are discussed in Section 14 3 and Section 14 18 14 8 G20 G21 Length Units Program G20 to use inches for length units Program G21 to use millimeters It is usually a good idea to program either G20 or G21 near the beginning of a program before any motion occurs and not to use either one anywhere else in the program It is the responsibility of the user to be sure all numbers are appropriate for use with the current length units CHAPTER 14 GCODES 140 14 9 G28 G30 Return to Predefined Absolute Position Two positions are defined by parameters 5161 5166 for G28 and parameters 5181 5186 for G30 The parameter values are in terms of the absolute coordinate system and the machine s native coordinate system To return to the predefined position by way of the programmed position program G28 X Y Z A B C or use G30 All axis words are optional The path is made by a traverse move from the current position to the programmed position followed by a traverse
100. 3 2 Offset display status bar oo 2 eee ees 106 10 3 3 Coordinate Display Arad coo A al ee e a 106 10 3 3 1 Baek plot sass ar Aw we Ae a Nw wee we e aw we 106 LAR Automate COOL o csi a da Re de 107 CONTENTS viii 10 34 2100 Program Display Area oca a Re ee ee a a 107 IAS MADUSLCOTEOL coca chee Eee Ree eG eee he eee heed eee eS 107 e ER ek dle we he a Se eR a a ee A ae a a 107 10 3 5 2The Spindle Group se ok ka aa a Rw we a a i 108 10 3 3 0 The Coplamt groUP r rs a e soaa ROR ee e ewe eds 108 10 336 Code EMY ii ei a ee PR Rok wee a a a ea ee a 108 OU IBID oca RA we ES chy we 108 a e e bh Ra eS Dee DARED eee eS 108 WORF wee oped nk ek Se Sab Pe ER oe wee a a A ew ee S 109 1038 Peod Override sa capan vei Gamat eG Ba Ree RM we ew bbe ache oo 109 10 3 9 Spindle speed Override cc eR EEE Swe ee ee be ee os 109 10 4 Keyboard Controls so i sacre ee a ea A a a ee a 109 11 Using The MINI Graphical Interface 110 EAE WO oa she odie es BRS ARAN 110 LL EFEC Taye ce he a a A A EE A RO we a Ae eo 111 US Mena Bar a es a E E o e 111 Lies Conto IO ES so edie deh ek BAS SE whee A al Eee gl 113 11 4 1 MANUAL oo ee Pa a RRR RRR EES ROR GE HS A a Se Ae we A 113 ILAS AUTO oo ho ate ee a A ee Ge ew A 114 Ll MO ege Be E eh ee Be ee Dies he eee Eee a E a 115 11 4 4 FEEDHOLD CONTINUE gt wee ee ee a 115 ieee ERORT oops sado DEER eee ee oe eS 115 LAG ESTOP LL uces se GE we Be Se we Be Be Ee he E es ee a ee a a 115 lee T
101. 4 INI 6 12 28 193 INPUT SCALE 33 Installing LiveCD 15 Installing manual 15 201 Installing script 15 iocontrol 46 Java 5 Jog Speed 98 105 keystick 5 29 Lathe 101 LeadScrew 194 LINEAR UNITS 32 Linux 4 MO 135 150 M1 135 150 M100 199 135 152 M2 135 150 M8 135 151 M30 135 150 M4 135 151 M48 135 151 M49 135 151 M5 135 151 M50 152 M51 152 M52 152 M53 152 M6 135 151 M60 135 150 M62 152 M63 152 M64 152 M65 152 M7 135 151 M8 135 151 M9 135 151 MachineOn 27 93 Manual 9 92 95 106 113 120 MAX ACCELERATION 32 MAX LIMIT 33 MAX VELOCITY 32 MDI 8 9 92 97 105 106 115 194 MIN FERROR 33 MIN LIMIT 33 mini 5 29 110 MIST 106 motion 46 NIST 3 194 NML 12 28 OMAC 3 Open 107 Open Source 14 OpenGL 91 Optional Block Delete 123 Optional Program Stop 123 127 Optional Stop 107 INDEX Pallet Shuttle 123 Parameters 128 Parport 74 Path Control Mode 126 Pause 107 pid 46 Pinout 23 PLC 7 Position Absolute 92 Position Actual 11 92 Position Commanded 11 92 Position Machine 11 Position Relative 11 92 Preview Plot 93 Program Extents 94 Python 91 100 RCS 3 Resume 107 return 153 RS274NGC 29 122 130 194 RS274NGC STARTUP CODE 30 RTAI 194 RTLINUX 194 Run 107 Servo Motor 194 SERVO PERIOD 31 Sherline 4 110 siggen 46 Signal Polarity 26
102. 5 0 000000 5246 0 000000 You should read this as moving the zero positions of G55 to X 2 units Y 1 unit and Z 2 units away from the absolute zero position Once there are values assigned a call to G55 in a program block would shift the zero reference by the values stored The following line would then move each axis to the new zero position Unlike G53 G54 through G59 3 are modal commands They will act on all blocks of code after one of them has been set The program that might be run using figure 21 1 would require only a single coordinate reference for each of the locations and all of the work to be done there The following code is offered as an example of making a square using the G55 offsets that we set above G55 GO xO yO zO gl f2 z 0 2000 xl CHAPTER 21 COORDINATE SYSTEM AND G92 OFFSETS 173 yl x0 yO gO zO g54 x0 yO zO m2 But you say why is there a G54 in there near the end Many programmers leave the G54 coordinate system with all zero values so that there is a modal code for the absolute machine based axis positions This program assumes that we have done that and use the ending command as a command to machine zero It would have been possible to use g53 and arrive at the same place but that command would not have been modal and any commands issued after it would have returned to using the G55 offsets because that coordinate system would still be in effect G54 use preset work coordinate system 1
103. 6 e AXIS_0 AXIS_n individual axis variables 5 3 7 e EMCIO emc s input and output variables 5 3 8 Each of these section names are on a line by themselves so you can quickly scan through the file CHAPTER 5 INI CONFIGURATION 30 5 2 3 Variables A variable line is made up of a variable name an equals sign and a value Everything from the first non whitespace character after the up to the end of the line is passed as the value so you can embed spaces in string symbols if you want to or need to A variable name is often called a keyword These variables and the values they are assigned are the way that the INI affects the operation of the EMC You can edit the values for each keyword in any text editor Changes don t take effect until the next time the controller is run The following sections detail each section of the configuration file using sample values for the configuration lines Some of the variables are used by EMC and must always use the section names and variable names shown Other variables are used only by HAL and the section names and variable names shown are those used in the sample configuration files 5 3 INI Variable Definitions 5 3 1 EMC Section VERSION SRevision 1 3 S The version number for the INI file The value shown here looks odd because it is automatically updated when using the Revision Control System It s a good idea to change this number each time you revise your file If yo
104. 7 M51 Spindle Speed Override Control 0 2 000000000000 15 5 M32 Adaptive Peed Control ec e mors s er ww Ee oi al De we 15 9 be Peed Stop Control cs s eor et aa eee A REE Rw OE oe eee oe 15 10 M62 to M65 Digital IO Control s se we ee ee ee 15 11 M100 to M199 User Defined Commands 2 0 0004 16 O Codes 16 1 Subroutines sub endsub return 6 6 EMO aa a a dd i A s 16 2 Looping do while endwhile break continue 16 3 Conditional iF else HOT co co o0 cosas 16 4 Indirection 17 Other Codes IFA JF Set Feed Rate cidad a A a a SD aa 17 2 S Set Spindle Speed lt lt cas a A id ee Ade ip Tedesco 18 Order of Execution 150 150 151 151 151 151 152 152 152 152 152 152 153 153 154 154 154 155 155 155 155 157 CONTENTS xii 19 G Code Best Practices 158 19 1 Use an appropriate decimal precision ooo o e 158 19 2 Use consistent white Spate co co ro nasg eaga Eaa a ee G 158 19 3 Prefer Center Tormat Aree lt daama ae a a a a 158 19 4 Put important modal settings at the top of the file 158 19 5 Dont put too many things on one line s es soes m e es sas o e a 159 19 6 Dont lice line numbers cosa merd toaa eaaa e e Pe h ae be e 159 20 Tool File and Compensation 160 20 1 TOOLS oo a a A RGD AA RA A A A AA AR rA 160 20 2 TO
105. 9 Temple Place Suite 330 Boston MA 02111 1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document but changing it is not allowed B 1 1 GNU Free Documentation License Version 1 1 March 2000 Copyright C 2000 Free Software Foundation Inc 59 Temple Place Suite 330 Boston MA 02111 1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document but changing it is not allowed O PREAMBLE The purpose of this License is to make a manual textbook or other written document free in the sense of freedom to assure everyone the effective freedom to copy and redistribute it with or without modifying it either commercially or noncommercially Secondarily this License preserves for the author and publisher a way to get credit for their work while not being considered responsible for modifications made by others This License is a kind of copyleft which means that derivative works of the document must themselves be free in the same sense It complements the GNU General Public License which is a copyleft license designed for free software We have designed this License in order to use it for manuals for free software because free software needs free documentation a free program should come with manuals providing the same freedoms that the software does But this License is not limited to software manuals it can be used for any textual work regardless of subject matt
106. A ee 74 8 1 1 De bo See eee eed wen aad Wha eee ea Ba RE SR ae BAe 74 8 1 2 REMOVE 2er a Se EE ee baw eae eee eS 75 8 1 3 A ccc ON ty wien a BFR Ee Beas ghey BE Poe Green ay Bodo A ac ve Qe ae 75 8 1 4 TOLIMA coa Be ie a Say Gee Bit ah al oe ol pl wo A 75 8 1 5 PUC ula IA 4 OR we A e e AA Se Ge a 77 8 1 6 COMMON PTODIEME lt saa maae ya a O Sew a de 77 eer A AI he Ge Bs SH es Eben we we Bee aa a 77 8 2 1 INSTANT ooo eo A ee OS a we Nw awe we ewe 77 moo O ok eA week ee Ew Eee Pee eG ee Ea ee Gee a oa i 77 8 3 1 Installing ooo emma isa nerd ee ee ew 78 8 3 2 READ A A AA O AA 78 8 3 3 PDS ee a a O a Net ae a a a wl El A le wt 78 8 3 4 e a a a a a a SA AE 78 8 3 5 aiee naii nc gk a a a ee ee el ew 79 CONTENTS E Deno ToGO RA Ee RR RE A a Die AS e oe 8 4 1 TUBERIA a a a e de e E EERE 8 4 2 REMOVIDOS ao A REE GD de e de ee ES A 8 4 3 PINS AR ee A ol we a 8 4 4 PATATAS ce ee a we a a a ee a a 8 4 5 TOTOCGUONS o a we a EA EA OES ae Oe we Ee A oe 8 5 Mesa Electronics m5i20 Anything I O Card o o 8 5 1 REMOVIDOS cc e ae ee ee a 8 5 2 DIOS reci cerio maa AA be hae e GA 8 5 3 PRICE a Shs a aes ey Ga a ae araea ds Ra 8 5 4 ii 2 so eaae Ne ae we Re te ea A A 8 00 Connector PIMOUL lt s erases eree ee RRR Re e Lc li A RN ano CONDESIOFES sis ias aia A O03 Conor Pato AR OR ha eM eae bo he ba bw bd A Gee LEDS ik se a Ee a Re oe ce eee EA ee Reca da 8 6 Vital Systems Motenc 100 and Motene LITE
107. A ee eee 14 18 G81 to G89 Canned Cycles 00 ae wee Pale a ae a 14 18 1 Preliminary and In Between Motion 00 000 15152 GOE Dre Cele a a ee a da Re aa 14 18 3 G82 Drilling Cycle with Dwell 130 130 131 131 132 132 132 133 133 133 134 134 134 134 CONTENTS 14 18 4 G83 14 18 5 G84 14 18 6 G85 14 18 7 G86 14 18 8 G87 14 18 9 G88 14 18 10 G89 14 18 11 G90 Peek Drie ui Gh a RE AR e Oe A eo Right Hand Tapping lt lt c4 0005 248 ca bbe ee ann tbeweea Boring No Dwell Peed OUt gt o a eo a ee ES ee Ee we Boring Spindle Stop Rapid Out oo o Back BOWING cord 2 CES de eee a Ee bee ees Boring Spindle Stop Manual Out o Boring Dwell Feed Out coi 02a Pa Rae Moe dBA ee ee Gol Set Distance Mode cca ce he ea wee eee Eee eee 14 19 G92 G92 1 G92 2 G92 3 Coordinate System Offsets 14 20 G93 G94 Set Feed Rate Mode usd Ra REE Mee OE whe wo 14 21 G98 G99 Set Canned Cycle Return Level o 000000 15M Codes 15 1 MO M1 M2 M30 M60 Program Stopping and Ending 15 2 M3 M4 M5 Spindle Control s es s rs ee ee ss 153 MB Tool Change cosacos EE A EO we Ae a ew 15 4 M7 MS M9 Coolant Control oc c lt eme 15 5 M48 M49 Override Control o ss c oc e mae a e ee aa 15 6 M50 Feed Override Control 06 65 8c ka ee A a a a eo 15
108. C language turns them off together see Section 15 4 12 2 7 Dwell A machining center may be commanded to dwell i e keep all axes unmoving for a specific amount of time The most common use of dwell is to break and clear chips so the spindle is usually turning during a dwell Regardless of the Path Control Mode see Section 12 2 15 the machine will stop exactly at the end of the previous programmed move as though it was in exact path mode 12 2 8 Units Units used for distances along the X Y and Z axes may be measured in millimeters or inches Units for all other quantities involved in machine control cannot be changed Different quantities use different specific units Spindle speed is measured in revolutions per minute The positions of rotational axes are measured in degrees Feed rates are expressed in current length units per minute or in degrees per minute as described in Section 12 2 5 12 2 9 Current Position The controlled point is always at some location called the current position and the controller always knows where that is The numbers representing the current position must be adjusted in the absence of any axis motion if any of several events take place 1 Length units are changed 2 Tool length offset is changed 3 Coordinate system offsets are changed 12 2 10 Selected Plane There is always a selected plane which must be the XY plane the YZ plane or the XZ plane of the machining center T
109. DRIVERS 81 8 5 Mesa Electronics m5i20 Anything I O Card The Mesa Electronics m5i20 card consists of an FPGA that can be loaded with a wide variety of configurations and has 72 pins that leave the PC The assignment of the pins depends on the FPGA configuration Currently there is a HAL driver for the 4 axis host based motion control configuration and this FPGA configurations is also provided with EMC2 It provides 8 encoder counters 4 PWM outputs normally used as DACs and up to 48 digital I O channels 32 inputs and 16 outputs Installing emc2 halcmd loadrt hal_m5i20 loadFpga 1 0 dacRate lt rate gt If loadFpga is 1 the default the driver will load the FPGA configuration on startup Ifit is O the driver assumes the configuration is already loaded dacRate sets the carrier frequency for the PWM outputs in Hz The default is 32000 for 32KHz PWM The driver prints some usefull debugging message to the kernel log which can be viewed with dmesg 8 5 1 Removing emc2S halemd unloadrt hal_m5i20 8 5 2 Pins In the following pins parameters and functions lt board gt is the board ID According to the naming conventions the first board should always have an ID of zero however this driver uses the PCI board ID so it may be non zero even if there is only one board e S32 m5i20 lt board gt enc lt channel gt count Encoder position in counts e 532 m5i20 lt board gt enc lt channel gt cnt latch
110. ED CYCLES 187 Example 8 Twelve holes in a square This example demonstrates the use of the L word to repeat a set of incremental drill cycles for successive blocks of code within the same G81 motion mode Here we produce 12 holes using five lines of code in the canned motion mode N1000 G90 GO X0 YO ZO move coordinate home N1010 G1 F50 X0 G4 P0 1 N1040 block Wee does these 3 does these 3 N1020 G91 G81 X1 YO Z 0 5 R1 L4 canned drill cycle po aZ N1030 X0 Y1 RO L3 repeat N1040 X 1 Y0 L3 repeat N1050 X0 Y 1 L2 repeat NISS biod N1060 G80 turn off canned cycle dc ars N1020 block N1070 G90 GO XO rapid home Ye x4 does thesea N1080 YO nonce N1090 ZO N1100 M2 program end The second reason to use a canned cycle is that they all produce preliminary moves and returns that you can anticipate and control regardless of the start point of the canned cycle Chapter 23 Image to gcode Milling depth maps X torus png AXIS File Machine View One Manual Control F3 MDI F5 Axis G XX torus png Image to gcode os di Units G20 in Invert Image Yes Normalize Image Yes Tolerance units 0 001 Pixel Size 0 006 Scan pattern Scan direction Depth units Y step pixels Tool Diameter units Safety Height units Tool Type Lace bounding Image size 400 x 400 pixels Minimum pixel value 0 Maximum pixel value 198 Contact angle Feed Rate units per minute 12 0
111. EL ES GO TO HOME POSITION MAX_VEL 1 000 3 000 SEARCH_VEL POSITIVE HOME_OFFSET 3 000 LATCH_VEL POSITIVE HOME 1 000 HOME SWITCH RELEASES USE_INDEX FALSE fo HOME SWITCH TRIPS SEARCH FOR HOME SWITCH SEARCH_VEL l BACK OFF OF HOME SWITCH SEARCH_VEL NAL DETECTION OF SWITCH LATCH_VEL a GO TO HOME POSITION MAX_VEL 1 000 3 000 SEARCH_VEL POSITIVE HOME_OFFSET 3 000 LATCH_VEL NEGATIVE HOME 1 000 HOME SWITCH RELEASES USE_INDEX TRUE Zp y HOME SWITCH TRIPS SEARCH FOR HOME SWITCH SEARCH_VEL FINAL DETECTION OF SWITCH AND INDEX PULSE LATCH_VEL GO TO HOME POSITION MAX_VEL 1 000 3 000 da PULSES SEARCH_VEL POSITIVE HOME_OFFSET 3 000 LATCH_VEL POSITIVE HOME 1 000 HOME SWITCH RELEASES USE_INDEX TRUE Mo HOME SWITCH TRIPS SEARCH FOR HOME SWITCH SEARCH_VEL BACK OFF OF HOME SWITCH SEARCH_VEL FINAL DETECTION OF SWITCH AND INDEX PULSE LATCH_VEL GO TO HOME POSITION MAX_VEL 1 000 Jn SU PULSES Figure 5 1 Homing Sequences 39 CHAPTER 5 INI CONFIGURATION 40 5 4 3 3 HOME_IGNORE_LIMITS HOME_IGNORE_LIMITS is another settable option in the AXIS_ section It s a boolean flag and can hold the values YES NO This flag determines whether EMC will ignore the limit switch inputs Some machine configurations do not use a separate home switch instead they route one of the limit switch signals to the home switch input as well In this
112. EPPER BASED SYSTEM 27 4 3 5 Adding PWM Spindle Speed Control If your spindle can be controlled by a PWM signal use the pwmgen component to create the signal loadrt pwmgen output_type 0 addf pwmgen update servo thread addf pwmgen make pulses base thread net spindle speed cmd motion spindle speed out gt pwmgen 0 value net spindle on motion spindle on gt pwmgen 0 enable net spindle pwm pwmgen 0 pwm gt parport 0 pin 09 out setp pwmgen 0 scale 1800 Change to your spindle s top speed in RPM This assumes that the spindle controller s response to PWM is simple 0 PWM gives ORPM 10 PWM gives 180 RPM etc If there is a minimum PWM required to get the spindle to turn follow the example in the nist lathe sample configuration to use a scale component 4 3 6 Adding an enable signal Some amplifiers drives require an enable signal before they accept and command movement of the motors For this reason there are already defined signals called Xen Yen Zen To connect them use the following example linksp Xen parport 0 pin 08 out You can either have one single pin that enables all drives or several depending on the setup you have Note however that usually when one axis faults all the other ones will be disabled aswell so having only one signal pin is perfectly safe 4 3 7 Adding an external ESTOP button As you can see in 4 3 1 by default the stepper configuration assumes no external ESTOP button
113. F8 toggle flood on flood off F9 toggle spindle forward off F10 toggle spindle reverse off F11 decrease spindle speed F12 increase spindle speed 11 7 2 Manual Mode 1 9 O set feed override to 10 90 O is 100 set feed override to O or feedhold x select X axis y select Y axis z select Z axis a select A axis b select B axis c select C axis Left Right Arrow jog X axis Up Down Arrow jog Y axis Page Up Down jog Z axis _ jog the active axis in the minus direction jog the active axis in the plus direction Home home selected axis il toggle through jog increments The following only work with a machine using auxiliary I O b take spindle brake off Alt b put spindle brake on 120 CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE 121 11 7 3 Auto Mode 1 9 0 set feed override to 10 90 O is 100 set feed override to O or feedhold o O open a program r R run an opened program p P pause an executing program s S resume a paused program a A step one line in a paused program 11 8 Misc One of the features of Mini is that it displays any axis above number 2 as a rotary and will display degree units for it It also converts to degree units for incremental jogs when a rotary axis has the focus Chapter 12 return Machining Center Overview This section gives a brief description of how a machining center is viewed from the input and output ends of the Interpreter It is assumed the reader is already familiar
114. G55 use preset work coordinate system 2 G56 use preset work coordinate system 3 G57 use preset work coordinate system 4 G58 use preset work coordinate system 5 G59 use preset work coordinate system 6 G59 1 use preset work coordinate system 7 G59 2 use preset work coordinate system 8 G59 3 use preset work coordinate system 9 21 3 1 Default coordinate system One other variable in the VAR file becomes important when we think about offset systems This variable is named 5220 In the default files its value is set to 1 00000 This means that when the EMC starts up it should use the first coordinate system as its default If you set this to 9 00000 it would use the nineth offset system as its default for startup and reset Any value other than an interger decimal really between 1 and 9 will cause the EMC to fault on startup 21 3 2 Setting coordinate system values within G code In the general programming chapter we listed a G10 command word This command can be used to change the values of the offsets in a coordinate system add here 21 4 G92 Offsets G92 is the most misunderstood and maligned part of EMC programming The way that it works has changed just a bit from the early days to the current releases This change has confused many users It should be thought of as a temporary offset that is applied to all other offsets In response to criticism of it Ray Henry studied it by comparing the way the interpreter authors expected it to work
115. HOME ALL sequence HOME_SEQUENCE numbers start with O and there may be no unused numbers 41 CHAPTER 5 INI CONFIGURATION 42 Chapter 6 Introduction 6 1 What is HAL HAL stands for Hardware Abstraction Layer At the highest level it is simply a way to allowa number of building blocks to be loaded and interconnected to assemble a complex system The Hardware part is because HAL was originally designed to make it easier to configure EMC for a wide variety of hardware devices Many of the building blocks are drivers for hardware devices However HAL can do more than just configure hardware drivers 6 1 1 HAL is based on traditional system design techniques HAL is based on the same principles that are used to design hardware circuits and systems so it is useful to examine those principles first Any system including a CNC machine consists of interconnected components For the CNC machine those components might be the main controller servo amps or stepper drives motors encoders limit switches pushbutton pendants perhaps a VFD for the spindle drive a PLC to run a toolchanger etc The machine builder must select mount and wire these pieces together to make a complete system 6 1 1 1 Part Selection The machine builder does not need to worry about how each individual part works He treats them as black boxes During the design stage he decides which parts he is going to use steppers or servos which brand of
116. IST A project EMC is able to run a wide range of motion devices EMCIO The module within EMCA that handles general purpose I O unrelated to the actual motion of the axes EMCMOT The module within EMC A that handles the actual motion of the cutting tool It runs as a real time program and directly controls the motors Encoder A device to measure position Usually a machanical optical device which outputs a quadrature signal The signal can be counted by special hardware or directly by the par port with emc2 Feed Relatively slow controlled motion of the tool used when making a cut Feedrate The speed at which a motion occurs In manual mode jog speed can be set from the graphical interface In auto or mdi mode feedrate is commanded using a f word F10 would mean ten units per minute Feedback Feedrate Override A manual operator controlled change in the rate at which the tool moves while cutting Often used to allow the operator to adjust for tools that are a little dull or anything else that requires the feed rate to be tweaked G Code The generic term used to refer to the most common part programming language There are several dialects of G code EMC uses RS274 NGC A GUI Graphical User Interface General A type of interface that allows communications between a computer and human in most cases via the manipulation of icons and other elements widgets on a computer screen EMC An application that presents a grap
117. L Preserve all the Invariant Sections of the Document unaltered in their text and in their titles Section numbers or the equivalent are not considered part of the section titles M Delete any section entitled Endorsements Such a section may not be included in the Modified Version N Do not retitle any existing section as Endorsements or to conflict in title with any Invariant Section If the Modified Version includes new front matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document you may at your option designate some or all of these sections as invariant To do this add their titles to the list of Invariant Sections in the Modified Version s license notice These titles must be distinct from any other section titles You may add a section entitled Endorsements provided it contains nothing but endorsements of your Mod ified Version by various parties for example statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard You may add a passage of up to five words as a Front Cover Text and a passage of up to 25 words as a Back Cover Text to the end of the list of Cover Texts in the Modified Version Only one passage of Front Cover Text and one of Back Cover Text may be added by or through arrangements made by any one entity If the Document already includes a cover text for the same cover previously added by you
118. OL Compensation lt lt ic aa a a a AA AA ee 161 20 9 Tool Lene Miss 204406 hak Rw RAR O A ae he dd woe a a 161 20 4 Cutter Radius Compensation cs ee a ee ee ee we els 162 20 4 1 Cutter Radius Compensation Detail lt s sos es sede aocor aa 0 00008 162 20 5 ToolCompensation Sources o ooe e koso oe ooe a a be a a A 169 21 Coordinate System and G92 Offsets 171 2I Darou AA 171 21 2 The Machine Position Command G53 se ss seses e sewa sea esaw 171 213 PikiureOlfbets C94 old cis ai aa as A a a ad a 171 21 51 Default coordimate system cosita REO a AR ee a wo 173 21 3 2 Setting coordinate system values within G code 0 173 DL Ge USAS css o e e a eRe Ra ak Re A i hw See oe a a 173 214 1 The G92 COmman ds o s se sace s a eed ee ae dk 174 2162 peting 4592 yalies mis cria AeA hee eb PO ew be es 174 Slave Wie Cannes ox caw ew ee ee we ee Ree a ae de eR eS 175 21 5 Sample Program Using Offsets ooo eara rana warga s easair eee 175 22 Canned Cycles 177 22 1 Preliminary Motion 26 6646 a She eR A EO we bee 177 Bove A a ee ee ee a a a ea eo 178 Bau A eac ae A Re oe OPER RP Se ee a ee ae eS 179 224 GEA CVO ik a ic a a a Re RR ee ae 181 aa OB is A e eee OEE PR A A ee OS 182 226 GETCIE co RA A id dc 182 eee CODEC A AA 183 a A A O 183 E A AAA 183 AM TS aa aa A a pe A e ees 185 dl CASIO Siri ot AP e ee AEE RR ee SE a WE ae ed wo ol Be we dia 185 ir AT GE Gases A oo HARE A Be ee Se we ew Dt aa eed Ge oe a 185 2
119. SS DS o to initial Z R A a SS ee Le Final Z position is intial F R Initial Position 0 0 07 Wht 3 14 06 423 a a 0 0 953 x0 yO 20 absolut home Fl A E solute Move mome Y 17 0000 na En FiO 90 xt y2 23 94 pl m3 s3000 4 91 g81 998 x4 y5 2 0 6r1 813 Z 4 8000 Ir m2 TASES Example 3 Relative Position G81 CHAPTER 22 CANNED CYCLES 181 Now suppose that you execute the first g81 block of code but from 0 O O rather than from 1 2 3 G90 G81 G98 X4 Y5 Z1 5 R2 8 Since OLD_Z is below the R value it adds nothing for the motion but since the initial value of Z is less than the value specified in R there will be an initial Z move during the preliminary moves Preliminary motion XT linear move to X and Y values Drilling cycle 5 Feedrate more from R to Rapid retum to R Preliminary motion We Zonk moreto R valve 0 0 0 Example 4 Absolute G81 R gt Z This is a plot of the path of motion for the second g81 block of code G91 G81 G98 X4 Y5 Z 0 6 R1 8 L3 Since this plot starts with 0 O 0 the interpreter adds the initial Z O and R 1 8 and rapids to that location After that initial z move the repeat feature works the same as it did in example 3 with the final z depth being 0 6 below the R value Preliminary motions More to second to first incremental dnll and retract location on W First drill More to third and retract drill and retract Wo 0 0 0
120. Stepper Stepper drives motors There are four main components to the EMC2 software a motion controller EMCMOT a discrete I O controller EMCIO a task executor which coordinates them EMCTASK and a collection of text based or graphical user interfaces An EMC2 capable of running a minimill must start some version of all four of these components in order to completely control it Each component is briefly described below In addition there is a layer called HAL Hardware Abstraction Layer which allows simple reconfiguration of EMC2 without the need of recompiling 1 5 1 Graphical User Interfaces A graphical interface is the part of the EMC2 that the machine tool operator interacts with The EMC2 comes with several types of user interfaces e an interactive command line program named emcpanel e a character based screen graphics program named keystick 1 3 e X Windows programs named xemc 1 6 and yeme e a Java based GUI emcgui e two Tcl Tk based GUIs named tkemc 1 5 and mini 1 4 e an OpenGL based GUI with an interactive G Code previewer called AXIS 1 2 CHAPTER 1 THE ENHANCED MACHINE CONTROL 6 File Machine View Help Ola e g Manual Control F3 MDI F5 Axis CI AO Continuous w Home Touch Off Override Limits Spindle J Stop ey al Brake Coolant T Mist Flood Feed Override 100 B Jog Speed 72 inmin AXIS 1 430 splash g code Not intended for actual milling 620
121. Title Page means for a printed book the title page itself plus such following pages as are needed to hold legibly the material this License requires to appear in the title page For works in formats which do not have any title page as such Title Page means the text near the most prominent appearance of the work s title preceding the beginning of the body of the text 2 VERBATIM COPYING You may copy and distribute the Document in any medium either commercially or noncommercially provided that this License the copyright notices and the license notice saying this License applies to the Document are reproduced in all copies and that you add no other conditions whatsoever to those of this License You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute However you may accept compensation in exchange for copies If you distribute a large enough number of copies you must also follow the conditions in section 3 You may also lend copies under the same conditions stated above and you may publicly display copies 3 COPYING IN QUANTITY If you publish printed copies of the Document numbering more than 100 and the Documents license notice requires Cover Texts you must enclose the copies in covers that carry clearly and legibly all these Cover Texts Front Cover Texts on the front cover and Back Cover Texts on the back cover Both covers must also clearly and legibly iden
122. Values of 1 will cause the motion to stop if M53 is active 15 10 M62 to M65 Digital IO Control To control a digital output bit program M P where the M word ranges from 62 to 65 and the P word ranges from O to an implementation defined maximum M62 Turn on digital output synched with motion M63 Turn off digital output synched with motion M64 Turn on digital output immediately M65 Turn off digital output immediately 15 11 M100 to M199 User Defined Commands To invoke a user defined command program M P Q where P and Q are both optional The external program Mnnn in the directory DISPLAY PROGRAM_PREFIX is executed with the P and O values as its two arguments Execution of the RS274NGC file pauses until the invoked program exits It is an error if e The specified User Defined Command does not exist Chapter 16 O Codes O codes provide for flow control in NC programs Each block has an associated number which is the number used after O Care must be taken to properly match the O numbers The behavior is undefined if e Other words are used on a line with an O word 16 1 Subroutines sub endsub return call Subroutines extend from a O sub to an O endsub The lines inside the subroutine the body are not executed in order instead they are executed each time the subroutine is called with o call 0100 sub subroutine to move to machine home GO XO YO ZO 0100 endsub
123. Y or Z axis of the machine coordinate system The axis or equivalently the plane perpendicular to the axis is selected with G17 Z axis XY plane G18 Y axis XZ plane or G19 X axis YZ plane If the arc is circular it lies in a plane parallel to the selected plane If a line of RS274 NGC code makes an arc and includes rotational axis motion the rotational axes turn at a constant rate so that the rotational motion starts and finishes when the XYZ motion starts and finishes Lines of this sort are hardly ever programmed If cutter radius compensation is active the motion will differ from what is described here See Chapter Two formats are allowed for specifying an arc We will call these the center format and the radius format In both formats the G2 or G3 is optional if it is the current motion mode 14 3 1 Radius format arcs In the radius format the coordinates of the end point of the arc in the selected plane are specified along with the radius of the arc Program G2 X Y Z A B C R or use G3 instead of G2 R is the radius The axis words are all optional except that at least one of the two words for the axes in the selected plane must be used The R number is the radius A positive radius indicates that the arc turns through 180 degrees or less while a negative radius indicates a turn of 180 degrees to 359 999 degrees If the arc is helical the value of the end point of the arc on the coordinate axis parallel to the a
124. Z a AeA N FY O Restart the spindle in the direction it was going This cycle is very similar to g82 except that it stops the spindle before it retracts the tool and restarts the spindle when it reaches the clearance value R 22 9 G87 Cycle The G87 cycle is intended for back boring The situation is that you have a through hole and you want to counter bore the bottom of hole To do this you put an L shaped tool in the spindle with a cutting surface on the UPPER side of its base You stick it carefully through the hole when it is not spinning and is oriented so it fits through the hole then you move it so the stem of the L is on the axis of the hole start the spindle and feed the tool upward to make the counter bore Then you stop the tool get it out of the hole and restart it This cycle uses I and J values to indicate the position for inserting and removing the tool I and J will always be increments from the X position and the Y position regardless of the distance mode setting This cycle also uses a K value to specify the position along the Z axis of the top of counterbore The K value is an absolute Z value in absolute distance mode and an increment from the Z position in incremental distance mode Preliminary motion as described above Move at traverse rate parallel to the XY plane to the point indicated by I and J Stop the spindle in a specific orientation Move the Z axis only at traverse rate downward to the
125. Z axis Program G83 X Y Z A B C R L Q 1 Preliminary motion as described above 2 Move the Z axis only at the current feed rate downward by delta or to the Z position whichever is less deep Rapid back out to the clear_z Rapid back down to the current hole bottom backed off a bit Repeat steps 1 2 and 3 until the Z position is reached at step 1 Q a fF 0 Retract the Z axis at traverse rate to clear Z It is an error if e the Q number is negative or zero CHAPTER 14 G CODES 147 14 18 5 G84 Right Hand Tapping This code is currently unimplemented in EMC2 It is accepted but the behavior is undefined 14 18 6 G85 Boring No Dwell Feed Out The G85 cycle is intended for boring or reaming but could be used for drilling or milling Program G85 X Y Z A B C R L 1 Preliminary motion as described above 2 Move the Z axis only at the current feed rate to the Z position 3 Retract the Z axis at the current feed rate to clear Z 14 18 7 G86 Boring Spindle Stop Rapid Out The G86 cycle is intended for boring This cycle uses a P number for the number of seconds to dwell Program G86 X Y Z A B C R L P 1 Preliminary motion as described above Move the Z axis only at the current feed rate to the Z position Dwell for the P number of seconds Stop the spindle turning Retract the Z axis at traverse rate to clear Z Oo a A WwW N Restart the spindle in the
126. Z position Move at traverse rate parallel to the XY plane to the X Y location Start the spindle in the direction it was going before Move the Z axis only at the given feed rate upward to the position indicated by K Move the Z axis only at the given feed rate back down to the Z position o JD YNp oONR O Stop the spindle in the same orientation as before CHAPTER 22 CANNED CYCLES 184 9 Move at traverse rate parallel to the XY plane to the point indicated by I and J 10 Move the Z axis only at traverse rate to the clear Z 11 Move at traverse rate parallel to the XY plane to the specified X Y location 12 Restart the spindle in the direction it was going before 667 preliminar mores from 0 0 0 Fto1 then X1 ond Y 1 d he 0 0 0 Example 6 Backbore Example six uses a incremental distances from 0 O 0 so the preliminary moves look much like those in example five but they are done using the G87 backbore canned cycle G91 G87 M3 1000 X1 Y1 Z 0 4 R1 4 I 0 1 J 0 1 K 0 1 You will notice that the preliminary moves shift the tool to directly above the center axis of the existing bore Location of tool Next it increments that location by the I and J values I after adding I and J offsets X with a plus value being added to the current X J Next the ca does the same for the Y axis 2 bottom loca For our example block both I and J are negative so they it moves the move back from the hole axi
127. a Input These buttons show a light green background whenever that mode is active You can also use the FEEDHOLD ABORT and ESTOP buttons to control a programmed move 11 4 1 MANUAL This button or pressing lt F3 gt sets the EMC to Manual mode and displays an abreviated set of buttons the operator can use to issue manual motion commands The labels of the jog buttons change to match the active axis Whenever Show_Mode_Full is active in in manual mode you will see spindle and lube control buttons as well as the motion buttons A keyboard lt i gt or lt I gt will switch from continuous jog to incremental jog Pressing that key again will toggle the increment size through the available sizes DEFAULT Speed 24 RAPID Ee 1 0000 O 0 1000 smaremant 0 0100 JOG Z JOG Z w 0 0010 _continnons w 0 0001 Figure 11 3 Manual Mode Buttons A button has been added to designate the present position as the home position We felt that a machine of this type Sherline 5400 would be simpler to operate if it didn t use a machine home position This button will zero out any offsets and will home all axes right where they are Axis focus is important here Notice in figure 11 1 that in manual mode you see a line or groove around the X axis to highlight its position display This groove says that X is the active axis It will be the target for jog moves made with the plus and minus jog buttons You can change axis focus by c
128. a we AE Ll oy hep a i a da 6 1 1 HAL is based on traditional system design techniques 6 1 1 1 Part Selection s o i cos a ae we a we a ee a aa 6 1 1 2 Interconnection Design o as esanera tat man al EE 6 1 1 3 Implememation s i5 ach a A ER da OR a aia i a OLLA Tong nw aa a a ee a 6 1 2 DAY e o e ths e e i Ae amp AA NN 62 HALCONCeplS scsi cars A RO e ls e a S 6 3 PAL Components siss gassas ad kasaad a a a a a 6 3 1 External Programs with HAL ho0kS o 6 3 2 Interval Components soor eais m a A RR RO ee a a i a eo 6 3 3 Hardware DVVES oosa ke eRe SHE EER eee ew eR be we CA 6 3 4 Tools aa o arte a Go we bee Be Ee ROS Ge ieee on cae ish Ae a ee dee we 6 4 Tinkertoys Erector Sets Legos andthe HAL o 6 4 1 DOE AAA EAGAE EATER EDALEERE EER SSD KDE ESS OES 6 4 2 Erector Sets coco Oe we we we ea 6 4 3 st fo tk EN 6 4 4 Alego Example coccion Ga Timing issues In HAL ociosa AAA AAA 66 Dynamic Linking and Configuration lt csceorcrssda rad a a HAL Tutorial Tel Before We etait 263 a ee a e a A Be we a fede l NOTATO o o oa oe o RA A A Ek we 7 1 2 The HPAP environne soros os s ate e Ew dab OE anaa dad Hae a SS T a Tapeompletion s ia RA A AA EE AAE ee ee ey i To ASmuple Example oec es doa ee a a a a a aea de ae a els 7 3 1 Loading a realtime component s o s so scons soe ee ee eee ee ee ee i 38 38 38 40 40 40 40 40 40 43 43 43 43 43 44
129. achine s current position is shown When a command is entered it is sent to emc to be executed A sample session of mdi is shown in Figure 9 6 9 7 axis remote Send remote commands to the AXIS GUI AXIS includes a program called axis remote which can send certain commands to a running AXIS The available commands are shown by running axis remote help and include check ing whether AXIS is running ping loading a file by name reloading the currently loaded file reload and making AXIS exit quit CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 100 Figure 9 6 MDI Session mdi emc2 configs sim emc nml MDI gt 0 0 0 0 0 0 0 0 0 0 0 0 MDI gt Gl F5 X1 MDI gt 0 5928500000000374 0 0 0 0 0 0 0 0 0 0 MDI gt 1 0000000000000639 0 0 0 0 0 0 0 0 0 0 9 8 hal_manualtoolchange Prompt the user to exchange tools AXIS includes a userspace hal component called hal_manualtoolchange which shows a window Figure 9 7 when a M6 command is issued After the OK button is pressed execution of the program will continue The HAL configuration file configs sim axis_manualtoolchange hal shows the HAL commands necessary to use this component hal_manualtoolchange can be used even when AXIS is not used as the GUI Figure 9 7 The Manual Toolchange Window E Insert tool 1 and click continue when E ready Continue 9 9 Python modules AXIS includes several Python modules which may be useful to
130. acter may be repeated for example 2 means the value of the parameter whose index is the integer value of parameter 2 13 3 3 Expressions and Binary Operations An expression is a set of characters starting with a left bracket and ending with a balancing right bracket In between the brackets are numbers parameter values mathematical operations and other expressions An expression may be evaluated to produce a number The expressions on a line are evaluated when the line is read before anything on the line is executed An example of an expression is 1 acos 0 3 x 4 0 2 Binary operations appear only inside expressions There are four basic mathematical operations addition subtraction multiplication and division There are three logical operations non exclusive or OR exclusive or XOR and logical and AND The eighth operation is the modulus operation MOD The ninth operation is the power operation xx of raising the number on the left of the operation to the power on the right The relational operators are equality EQ inequality NE strictly greater than GT greater than or equal to GE strictly less than LT and less than or equal to LE The binary operations are divided into three groups The first group is power The second group is multiplication division and modulus The third group is addition subtraction logical non exclusive or logical
131. active things by writing their values into the MESSAGE pad Program _File will write the currently active program file name Editor_File will write the currently active file if the editor pop in is active and a file has been selected for editing Parameter_File will write the name of the file being used for program parameters You can find more on this in the chapters on offsets and using variables for programming Tool_File will write the name of the tool file that is being used during this run Active_G Codes will write a list of all of the modal program codes that are active whenever this item is selected For more information about modal codes see the introductory part programming chapter Help opens a text window pop in that displays the contents of the help file CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE 113 You will notice between the info menu and the help menu there are a set of four buttons These are called check buttons because they have a small box that shows red if they have been selected These four buttons Editor Backplot Tools and Offsets pop in each of these screens If more than one pop in is active button shown as red you can toggle between these pop ins by right clicking your mouse 11 4 Control Button Bar Below the menu line is a horizontal line of control buttons These are the primary control buttons for the interface Using these buttons you can change mode from MANUAL to AUTO to MDI Manual Dat
132. ad siggen thread 1 01 mSec stepgen thread 50 3 uSec Multiplier 1 Record Length C 16191 samples 1 channel C 8095 samples 2 channels 4047 samples 4 channels C 2023 samples 8 channels C 1011 samples 16 channels OK Quit Figure 7 4 Realtime function not linked dialog This dialog is where you set the sampling rate for the oscilloscope For now we want to sample once per millisecond so click on the 1 03mS thread slow formerly siggen thread see footnote and leave the multiplier at 1 We will also leave the record length at 4047 samples so that we can use up to four channels at one time When you select a thread and then click OK the dialog disappears and the scope window looks something like figure 7 5 5Several of these screen captures refer to threads named siggen thread and stepgen thread instead of slow and fast When the screenshots were captured the threads component didn t exist and a different method was used to create threads giving them different names Also the screenshots show pins etc as stepgen xxx rather than freqgen xxx The original name of the freqgen module was stepgen and I haven t gotten around to re doing all the screen shots since it was renamed The name stepgen now refers to a different step pulse generator one that accepts position instead of velocity commands Both are described in detail later in this d
133. ajPeriod respectively the actual times would depend on the ini That is one part of the config process and although it could be done manually it would normally be automatic The next step is to decide what each thread needs to do Some of those decisions would also be automatic the motion module would automatically connect its PlanTrajectory function to the TrajPeriod thread and its ControlMotion function to the ServoPeriod thread Other connections would be made by the integrator at least the first time These might include hooking the STG driver s encoder read and DAC write functions to the servo thread or hooking stepgen s function to the fast thread along with the parport function s to write the steps to the port 6 6 Dynamic Linking and Configuration It is indeed possible to configure HAL with a form of dynamic linking But it is different than DLLs as used by Microsoft tm or shared libraries as used in Linux Both DLLs and shared libraries essentially say Here I am I have this code you might want to use where you is other modules Then when those other modules or programs are loaded they say I need a function called X is there one and if the answer is YES they link to it With HAL a component still says Here I am I have this code you might want to use but you is the system integrator The integrator gets to decide what functions are used and doesn t have to worry about another module needing f
134. al 4 3 4 Changing the polarity of a signal 4 3 5 Adding PWM Spindle Speed Control 4 3 6 Adding an enable signal 4 3 7 Adding an external ESTOP button INI Configuration 5 1 Files Used for Configuration 5 2 TheINI File Layout 5 2 1 CTE es kana a ES ae OCU bo pe Gk Ge EERTE 5 2 3 Variables 4424 98 44 ense 5 3 INI Variable Definitions Sel EMC Section 5 3 2 DISPLAY Section 5 3 3 EMCMOT Section fe a TASK Section 5 3 5 HAL section 5 3 6 TRAJ Section FST AXIS_ lt num gt Section 5 3 7 1 Homing related items 5 3 7 2 Servo related items 5 3 7 3 Stepper related items 5 3 8 EMCIO Section 5 4 Homing sd ERE ES 5 4 1 UNEN o Ge ee eG 5 4 2 Homing Sequence iii 19 19 20 21 21 23 23 23 23 24 26 26 26 27 27 27 CONTENTS 6 7 5 4 3 CONUIBULACION 2 5 64 gn ee ERA AA A O we a ee ds a amp Data HOME SEARCH VEL 23 coche hae She ee eae ewe ed 0432 HOME LATCH VEL a ces co ce ee RS eri we A ee ee we we 5 4 3 3 HOME_IGNORE_LIMITS a ee ee 5434 HOME USE INDEX 2 oi tonne nie Goede e eae eae eee GAA 5 4 3 5 HOME OFFSET cb web Oe ee a a ee ee A Peo HOME cio A RE RR ee ew a ee be ew Gata HOME IS SHARED ooo orar e ee ee eee 5 4 3 8 HOME SEQUENCE ee ee ee Introduction G What oe eek es oh we eg
135. all about If you are comfortable with the idea of interconnecting hardware black boxes you will probably have little trouble using HAL to interconnect software black boxes CHAPTER 6 INTRODUCTION 45 6 2 HAL Concepts This section is a glossary that defines key HAL terms but it is a bit different than a traditional glossary because these terms are not arranged in alphabetical order They are arranged by their relationship or flow in the HAL way of things Component When we talked about hardware design we referred to the individual pieces as parts building blocks black boxes etc The HAL equivalent is a component or HAL component This document uses HAL component when there is likely to be confusion with other kinds of components but normally just uses component A HAL component is a piece of software with well defined inputs outputs and behavior that can be installed and interconnected as needed Parameter Many hardware components have adjustments that are not connected to any other components but still need to be accessed For example servo amps often have trim pots to allow for tuning adjustments and test points where a meter or scope can be attached to view the tuning results HAL components also can have such items which are referred to as parameters There are two types of parameters Input parameters are equivalent to trim pots they are values that can be adjusted by the user and remain fixed once they are
136. am Stop Switch The optional program stop switch works as follows If this switch is on and an input RS274 NGC code line contains an M1 code program execution is supposed to stop until the cycle start button is pushed EMC2 checks the optional stop switch when the OPTIONAL _PROGRAM_STOP canonical function call is executed and either stops if the switch is on or not if the switch is off 12 4 Tool File A tool file is required to use the Interpreter The file tells which tools are in which carousel slots and what the length and diameter of each tool are The format of a tool file is exemplified in Table 12 1 Table 12 1 Sample Tool File Pocket FMS TLO Diameter Comment 1 1 2 0 1 0 2 2 1 0 0 2 5 5 1 5 0 25 endmill 10 10 2 4 0 3 for testing 21 21 173 740 0 1 2 spot drill 32 32 247 615 0 8 5mm drill Al 41 228 360 0 10mm tap 60 60 0 0 large chuck The file consists of any number of header lines followed by one blank line followed by any number of lines of data The header lines are ignored It is important that there be exactly one blank line with no spaces or tabs even before the data The header line shown in Table 12 1 describes the data columns so it is suggested but not required that such a line always be included in the header Each data line of the file contains the data for one tool Each line has five entries The first four entries are required The las
137. are supported for even longer Ubuntu uses the very best in translations and accessibility infrastructure that the Free Soft ware community has to offer to make Ubuntu usable for as many people as possible Ubuntu is released regularly and predictably a new release is made every six months You can use the current stable release or help improve the current development release e The Ubuntu community is entirely committed to the principles of free software development we encourage people to use open source software improve it and pass it on 2 2 EMC Download Page You will find the most recent releases of EMC2 announced on www linuxcnc org The releases of EMC2 will be done in two ways sources and binary package The sources described in the Developers Handbook consist of a tarball emc2 lt version gt tar gz which you should download and unpack into your home directory This document oriented towards the end user will only try to explain how to install the binary package on the Ubuntu distribution l Ubuntu is an ancient African word meaning humanity to others Ubuntu also means I am what I am because of who we all are The Ubuntu Linux distribution brings the spirit of Ubuntu to the software world You can read more about it at http www ubuntu com 2For information regarding other Linux variants check the Developers Handbook or ask for help on the emc developers mailing list http sourceforge net mail
138. as been homed The position can be changed to display any one of several values by using the menu settings The startup or default settings can be changed in the ini file so these displays wake up just the way that you want them CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE 117 11 5 2 Feedrate Override Immediately below the axis position displays is the feedrate override slider You can operate feed rate override and feedhold in any mode of operation Override will change the speed of jogs or feed rate in manual or MDI modes You can adjust feed rate override by grabbing the slider with your mouse and dragging it along the groove You can also change feed rate a percent at a time by clicking in the slider s groove In auto mode you can also set feed override in 10 increments by pressing the top row of numbers This slider is a handy visual reference to how much override is being applied to programmed feedrate 11 5 3 Messages The message display located under the axis positions is a sort of scratch pad for the EMC If there are problems it will report them there If you try to home or move an axis when the ESTOP button is pressed you ll get a message that says something about commanding motion when the EMC is not ready If an axis faults out for something like falling behind the message pad will show what happened If you want to remind an operator to change a tool for example you can add a line of code to your program that will displ
139. ased under this License The Cover Texts are certain short passages of text that are listed as Front Cover Texts or Back Cover Texts in the notice that says that the Document is released under this License A Transparent copy of the Document means a machine readable copy represented in a format whose specifi cation is available to the general public whose contents can be viewed and edited directly and straightforwardly with generic text editors or for images composed of pixels generic paint programs or for drawings some widely available drawing editor and that is suitable for input to text formatters or for automatic translation to a vari ety of formats suitable for input to text formatters A copy made in an otherwise Transparent file format whose markup has been designed to thwart or discourage subsequent modification by readers is not Transparent A copy that is not Transparent is called Opaque Examples of suitable formats for Transparent copies include plain ASCII without markup Texinfo input format BIFX input format SGML or XML using a publicly available DTD and standard conforming simple HTML designed for human modification Opaque formats include PostScript PDF proprietary formats that can be read and edited only by proprietary word processors SGML or XML for which the DTD and or processing tools are not generally available and the machine generated HTML produced by some word processors for output purposes only The
140. ash 2 an optional line number 3 any number of words parameter settings and comments 4 an end of line marker carriage return or line feed or both Any input not explicitly allowed is illegal and will cause the Interpreter to signal an error 130 CHAPTER 13 LANGUAGE OVERVIEW 131 Spaces and tabs are allowed anywhere on a line of code and do not change the meaning of the line except inside comments This makes some strange looking input legal The line g0x 0 12 34y 7 is equivalent to g0 x 0 1234 y7 for example Blank lines are allowed in the input They are to be ignored Input is case insensitive except in comments i e any letter outside a comment may be in upper or lower case without changing the meaning of a line 13 2 Line Number A line number is the letter N followed by an integer with no sign between O and 99999 written with no more than five digits 000009 is not OK for example Line numbers may be repeated or used out of order although normal practice is to avoid such usage Line numbers may also be skipped and that is normal practice A line number is not required to be used but must be in the proper place if used 13 3 Word A word is a letter other than N followed by a real value Words may begin with any of the letters shown in Table 13 1 The table includes N for completeness even though as defined above line numbers are not words Several letters I J K L P R may
141. ated linear motion to the destination point at a rate dependant on the speed of the spindle It is an error if CHAPTER 14 G CODES 139 e all axis words are omitted e the spindle is not turning when this command is executed e the requested linear motion exceeds machine velocity limits due to the spindle speed 14 5 G4 Dwell For a dwell program G4 P This will keep the axes unmoving for the period of time in seconds specified by the P number It is an error if e the P number is negative 14 6 G10 Set Coordinate System Data The RS274 NGC language view of coordinate systems is described in Section12 6 To set the coordinate values for the origin of a coordinate system program G10 L2 P X Y Z A B C where the P number must evaluate to an integer in the range 1 to 9 corresponding to G54 to G59 3 and all axis words are optional The coordinates of the origin of the coordinate system specified by the P number are reset to the coordinate values given in terms of the absolute coordinate system Only those coordinates for which an axis word is included on the line will be reset It is an error if e the P number does not evaluate to an integer in the range 1 to 9 If origin offsets made by G92 or G92 3 were in effect before G10 is used they will continue to be in effect afterwards The coordinate system whose origin is set by a G10 command may be active or inactive at the time the G10 is executed Example G10 L
142. ation about the current state of the HAL To show all installed components halcmd show comp Loaded HAL Components ID Type Name PID State 32769 RT siggen ready 9775 User halcmd9775 9775 initializing CHAPTER 7 HAL TUTORIAL 54 Since halcmd itself is a HAL component it will always show up in the list The list also shows the siggen component that we installed in the previous step The RT under Type indicates that siggen is a realtime component Next let s see what pins siggen makes available halcmd show pin Component Pins Owner Type Dir Value Name 02 float W 0 00000e 00 siggen 0 cosine 32769 float OUT 0 00000e 00 siggen 0 sawtooth 32769 float OUT 0 00000e 00 siggen 0 sine 32769 float OUT 0 00000e 00 siggen 0 square 32769 float OUT 0 00000e 00 siggen 0 triangle This command displays all of the pins in the HAL a complex system could have dozens or hundreds of pins But right now there are only five pins All five of these pins are floating point and all five carry data out of the siggen component Since we have not yet executed the code contained within the component all the pins have a value of zero The next step is to look at parameters halcmd show param Parameters Owner Type Dir Value Name 32769 float RW 1 00000e 00 siggen 0 amplitude 32769 float RW 1 00000e 00 siggen 0 frequency 32769 float RW 0 00000e 00 siggen 0 offset 32769 s32 RO 0 siggen 0 update time 32769 s32 RW 0 siggen 0
143. ave the neccessary information CHAPTER 8 HARDWARE DRIVERS 82 e BIT m5i20 lt board gt in lt channel gt State of digital input pin see canonical digital input e BIT m5i20 lt board gt in lt channel gt not Inverted state of digital input pin see canonical digital input e BIT m5i20 lt board gt out lt channel gt Value to be written to digital output see canonical digital output e BIT m5i20 lt board gt estop in Dedicated estop input more details needed e BIT m5i20 lt board gt estop in not Inverted state of dedicated estop input e BIT m5i20 lt board gt watchdog reset Bidirectional Set TRUE to reset watchdog once is automatically cleared If bit value 16 is set in watchdog control then this value is not used and the hardware watchdog is cleared every time the dac write function is executed 8 5 3 Parameters e FLOAT m5i20 lt board gt enc lt channel gt scale The number of counts user unit to convert from counts to units e FLOAT m5i20 lt board gt dac lt channel gt offset Sets the DAC offset e FLOAT m5i20 lt board gt dac lt channel gt gain Sets the DAC gain scaling e BIT m5i20 lt board gt dac lt channel gt interlaced Sets the DAC to interlaced mode Use this mode if you are filtering the PWM to generate an anaolg voltage 1 e BIT m5i20 lt board gt out lt channel gt invert Inverts a digital ou
144. ay in the message box An example might be msg change to tool 3 and press resume This line of code included in a program will display change to tool 3 and press resume in the message box The word msg with comma included is the command to make this happen without msg the message wouldn t be displayed It will still show in the auto modes display of the program file To erase messages simply click the message button at the top of the pad or on the keyboard hold down the Alt key and press the m key 11 6 Right Column The right column is a general purpose place to display and work Here you can see the modal buttons and text entry or displays Here you can view a plot of the tool path that will be commanded by your program You can also write programs and control tools and offsets here The modal screens have been described above Each of the popin displays are described in detail below 11 6 1 Program Editor fila edit osttings scripts z Figure 11 5 Mini Text Editor The editor is rather limited compared to many modern text editors It does not have undo nor paste between windows with the clipboard These were eliminated because of interaction with a running program Future releases will replace these functions so that it will work the way you ve come to expect from a text editor It is included because it has the rather nice feature of being able to number and renumber lines in the way that the interpreter e
145. ays represent increments regardless of the distance mode setting K numbers represent increments in all but one usage see Section 14 18 8 where the meaning changes with distance mode 14 19 G92 G92 1 G92 2 G92 3 Coordinate System Offsets See Section 12 6 for an overview of coordinate systems To make the current point have the coordinates you want without motion program G92 X Y Z A B C where the axis words contain the axis numbers you want All axis words are optional except that at least one must be used If an axis word is not used for a given axis the coordinate on that axis of the current point is not changed It is an error if 1 all axis words are omitted When G92 is executed the origin of the currently active coordinate system moves To do this origin offsets are calculated so that the coordinates of the current point with respect to the moved origin are as specified on the line containing the G92 In addition parameters 5211 to 5216 are set to the X Y Z A B and C axis offsets The offset for an axis is the amount the origin must be moved so that the coordinate of the controlled point on the axis has the specified value Here is an example Suppose the current point is at X 4 in the currently specified coordinate system and the current X axis offset is zero then G92 x7 sets the X axis offset to 3 sets parameter 5211 to 3 and causes the X coordinate of the current point to be 7 The axis offsets are alw
146. ays used when motion is specified in absolute distance mode using any of the nine coordinate systems those designated by G54 G59 3 Thus all nine coordinate systems are affected by G92 Being in incremental distance mode has no effect on the action of G92 Non zero offsets may be already be in effect when the G92 is called If this is the case the new value of each offset is A B where A is what the offset would be if the old offset were zero and B is the old offset For example after the previous example the X value of the current point is 7 If G92 x9 is then programmed the new X axis offset is 5 which is calculated by 7 9 3 To reset axis offsets to zero program G92 1 or G92 2 G92 1 sets parameters 5211 to 5216 to zero whereas G92 2 leaves their current values alone To set the axis offset values to the values given in parameters 5211 to 5216 program G92 3 You can set axis offsets in one program and use the same offsets in another program Program G92 in the first program This will set parameters 5211 to 5216 Do not use G92 1 in the remainder of the first program The parameter values will be saved when the first program exits and restored when the second one starts up Use G92 3 near the beginning of the second program That will restore the offsets saved in the first program If other programs are to run between the the program that sets the offsets and the one that restores them make a copy of the parameter file writ
147. be executed in order every time the thread runs As an example suppose we have a parport component named hal_parport That component defines one or more HAL pins for each physical pin The pins are described in that component s doc section their names how each pin relates to the physical pin are they inverted can you change polarity etc But that alone doesn t get the data from the HAL pins to the physical pins It takes code to do that and that is where functions come into the picture The parport component needs at least two functions one to read the physical input pins and update the HAL pins the other to take data from the HAL pins and write it to the physical output pins Both of these functions are part of the parport driver 6 3 HAL components Each HAL component is a piece of software with well defined inputs outputs and behavior that can be installed and interconnected as needed This section lists available components and a brief description of what each does Complete details for each component are available later in this document 6 3 1 External Programs with HAL hooks motion A realtime module that accepts NML motion commands and interacts with HAL iocontrol A user space module that accepts NML I O commands and interacts with HAL classicladder A PLC using HAL for all I O halui A user space program that interacts with HAL and sends NML commands it is intended to work as a full User Interface using external knobs amp swi
148. bes the interactions in more detail In no case does the Interpreter know what the setting of any of these switches is 12 3 1 Feed and Speed Override Switches The Interpreter will interpret RS274 NGC commands which enable M48 or disable M4 9 the feed and speed override switches It is useful to be able to override these switches for some machining operations The idea is that optimal settings have been included in the program and the operator should not change them EMC2 reacts to the setting of the speed or feed override switches on the control panel when these switches are enabled 12 3 2 Block Delete Switch If the block delete switch is on lines of RS274 NGC code which start with a slash the block delete character are not interpreted If the switch is off such lines are interpreted The Interpreter runs in two stages read and execute The driver tells the Interpreter when to perform each stage When the Interpreter reads a line starting with a slash it informs the driver CHAPTER 12 RETURN MACHINING CENTER OVERVIEW 127 I just read a line starting with a slash The driver checks the setting of the block delete switch If the switch is off it tells the Interpreter Execute that line If the switch is on the driver does not tell the Interpreter to execute the line Instead it tells the Interpreter to read another line with the result that the line starting with the slash is not executed 12 3 3 Optional Progr
149. by left clicking on any empty desktop space Type in the name of your machine where it says name Type in a command like that shown above in the Command space and tick the Run in terminal checkbox The OK button will put the icon on the desktop You can even select a custom EMC2 icon to use if you wish Users of other distributions will need to explore the way that their desktop system works to build these kind of custom launcher icons CHAPTER 3 RUNNING EMC2 Figure 3 3 Create Launcher Icon Create Launcher Name My Router Generic name Comment Command emc emc2 configs stepper stepp Browse Application V Run in terminal 22 Chapter 4 Basic configurations for a stepper based system 4 1 Introduction This chapter describes some of the more common settings that users want to change when setting up EMC2 Because of the various possibilities of configuring EMC2 it is very hard to document them all and keep this document relatively short The most common EMC2 usage as reported by our users is for stepper based systems These systems are using stepper motors with drives that accept step amp direction signals It is one of the simpler setups because the motors run open loop no feedback comes back from the motors yet the system needs to be configured properly so the motors don t stall or lose steps Most of this chapter is based on the sample config released along with EMC2 The co
150. by unary operations which return angle measures ACOS ASIN and ATAN are also in degrees The FIX operation rounds towards the left less positive or more negative on a number line so that FIX 2 8 2 and FIX 2 8 3 for example The FUP operation rounds towards the right more positive or less negative on a number line FUP 2 8 3 and FUP 2 8 2 for example 13 4 Parameter Setting A parameter setting is the following four items one after the other 1 a pound character 2 a real value which evaluates to an integer between 1 and 5399 3 an equal sign and 4 a real value For example 3 15 is a parameter setting meaning set parameter 3 to 15 A parameter setting does not take effect until after all parameter values on the same line have been found For example if parameter 3 has been previously set to 15 and the line 3 6 G1 x 3 is interpreted a straight move to a point where x equals 15 will occur and the value of parameter 3 will be 6 13 5 Comments and Messages Printable characters and white space inside parentheses is a comment A left parenthesis always starts a comment The comment ends at the first right parenthesis found thereafter Once a left parenthesis is placed on a line a matching right parenthesis must appear before the end of the line Comments may not be nested it is an error if a left parenthesis is found after the start of a comment and before the end of the comm
151. ch as 1 1 2 19 6 Don t use line numbers Line numbers offer no benefits When line numbers are reported in error messages the numbers refer to the line number in the file not the N word value Chapter 20 Tool File and Compensation 20 1 Tool File The EMC uses a tool file that is read in when a machine control is started In a standard release this file is named emc var generic var or sim var and is used by the similarly named run file The specific name of the file that will be used is set by the ini file that is read at startup A tool file is required It tells which tools are in which carousel slots and what the length and diameter of each tool are The Interpreter does not deal directly with tool files A tool file is read by the EMC system and the Interpreter gets the tool information by making calls to canonical functions that obtain it The header line shown in Table 20 1 is essential for some of the graphical interfaces so it is sug gested but not required that such a line always be included as the first line in the file Each data line of the file contains the Figure 20 1 Typical Tool File data for one tool Each line has five entries The first four entries are re POC FMS LEN DIAM COMMENT q quired The last entry a comment is 1 1 1 565 0 250 Drill optional It makes reading easier if 2 2 1 000 0 247 Reground End Mill the entries are arranged in columns 3 3 1 125
152. cond SERVO_PERIOD 1000000 Servo task period is also in nanoseconds This value will be rounded to an integer multiple of BASE_PERIOD Most systems will not need to change this value It is the update rate of the low level motion planner You ll need it even if you only have steppers TRAJ_PERIOD 10000000 Trajectory Planner task period in nanoseconds This value will be rounded to an integer multiple of SERVO_PERIOD Folk with fast computers have found that reducing this value by half will give them smother motion blending during contour cutting 5 3 4 TASK Section The TASK section contains general parameters for EMCTASK which includes primarily the NC language interpreter and the sequencing logic for sending commands to EMCMOT and EMCIO CYCLE_TIME 0 100 The period in seconds at which EMCTASK will run This parameter mostly affects the polling interval when waiting for motion to complete or when executing a pause instruction It no longer affects the throughput when transferring segments to the real time layer Making it 0 0 or a negative number will tell EMCTASK not to sleep at all 5 3 5 HAL section The HAL section lists files and commands to setup the Hardware Abstraction Layer If this is a stepper system you might see several files here The exact set would depend upon the configuration of signals at the parallel port At a minimum you would see the following Sherline mills use the standard_pinout and xylote
153. configs E demo_mazak HF demo_step_cl etch servo E hexapod sim E m5i20 This configuration step is intended for basic stepper machines You can have either standard pinout EMC style or xylotex pinout by including either one of those 2 hal files Certainly you could make a new one which would suit your own custom cabling There are 2 ini files one for inch setups stepper_in ini and one for metric setups stepper_mm ini Detailed description ini files stepper_in ini inch setup for a stepper machine stepper_mm ini metric setup for a stepper machine nml files max motenc it uses a default nml file found in sim configs common emc nml axis mini hal files tkemc Huana a dnfault atannas hal fila start from scratch and write a new configuration A user can quickly copy etc emc2 into the home directory and prune out those configurations that are not ever going to be used Or you can create a new emc2 configs directory in home and copy or drag in those configurations that you want to try modifying 3 2 Copying Sample Configurations The files in etc emc2 configs are just samples You should copy them to your home directory before modifying them There are three possible ways to make a copy of an existing configuration copy and paste 3 2 1 drag and drop 3 2 2 and command line3 2 3 Any one of these will copy a sample configuration 3 2 1 Copy and Paste Here s how to do
154. ctions write with no Invariant Sections instead of saying which ones are invariant If you have no Front Cover Texts write no Front Cover Texts instead of Front Cover Texts being LIST likewise for Back Cover Texts If your document contains nontrivial examples of program code we recommend releasing these examples in parallel under your choice of free software license such as the GNU General Public License to permit their use in free software Index axisrc 103 emcre 28 ABORT 10 Acme Screw 192 ANGULAR UNITS 32 Auto 8 9 106 111 114 121 AXIS 5 29 91 100 AXIS 0 1 2 29 Backlash 192 Backlash Compensation 192 backplot 111 118 Ball Nut 192 Ball Screw 192 BASE PERIOD 30 Block Delete 126 blocks 46 break 154 Bridgeport 4 call 153 classicladder 46 CNC 4 43 92 110 192 Comments 29 continue 154 Coolant 96 108 123 125 Coordinate Systems 129 CVS 4 DISPLAY 29 do 154 DRO 193 Dwell 125 EDM 193 else 154 EMC 29 193 emcgui 5 EMCIO 7 29 193 EMCMOT 29 193 emcpanel 5 EMCTASK 7 enable signal 27 Encoder 193 encoder 33 46 endif 154 endsub 153 endwhile 154 ESTOP 10 27 92 93 105 106 115 Feed 193 Feed Override 92 97 105 117 123 193 Feed Rate 124 Feedrate 193 Feedrate Override 10 FERROR 33 freqgen 46 G Code 193 G code 8 GO 135 136 Gl 135 136 G10 135 139 G17 135 139 G18 135 139 G19
155. d period1 1000000 CHAPTER 7 HAL TUTORIAL 57 loadrt siggen signals links F parameter values setp siggen 0 amplitude 5 00000e 00 setp siggen 0 frequency 1 00000e 00 setp siggen 0 offset 0 00000e 00 realtime thread function links addf siggen 0 update test thread The output of the save command is a sequence of HAL commands If you start with an empty HAL and run all these commands you will get the configuration that existed when the save command was issued To save these commands for later use we simply redirect the output to a file halcmd save all saved hal 7 3 6 Restoring the HAL configuration To restore the HAL configuration stored in saved hal we need to execute all of those HAL commands To do that we use halcmd f lt filename gt which reads commands from a file emc2S halcmd f saved hal 7 4 Looking at the HAL with halmeter You can build very complex HAL systems without ever using a graphical interface However there is something satisfying about seeing the result of your work The first and simplest GUI tool for the HAL is halmeter It is a very simple program that is the HAL equivalent of the handy Fluke multimeter or Simpson analog meter for the old timers We will use the siggen component again to check out halmeter If you just finished the previous example then siggen is already loaded If not we can load it just like we did before emc2 halrun halcmd loadrt siggen
156. d that result is used as the initial level for a G98 The same value is the computed R value so G99 will also return to the same place Incremental distance return with R gt 0 praus mat Return A When the value of R is less than OLD_Z and incremental distance mode is turned on G98 will return the tool to the A E eee value of OLD_Z Under those conditions G99 will retract i incremental the tool to OLD_Z plus the negative R value The return will be below OLD_Z 0 0 0 22 13 Why use a canned cycle There are at least two reasons for using canned cycles The first is the economy of code A single bore would take several lines of code to execute Example 1 above demonstrated how a canned cycle could be used to produce 8 holes with ten lines of nc code within the canned cycle mode The program below will produce the same set of 8 holes using five lines for the canned cycle It does not follow exactly the same path nor does it drill in the same order as the earlier example But the program writing economy of a good canned cycle should be obvious Example 7 Eight Holes Revisited n100 g90 g0 x0 yO z0 move coordinate home n110 gl 10 x0 g4 p0 1 NOD Eik does these A n120 g91 g81 x1 yO z 1 rl 14 canned drill cycle Tis n130 g90 g0 x0 yl N120 block does these4a K n140 z0 n150 g91 g81 x1 yO z 5 rl 14 canned drill cycle 0 0 0 n160 g80 turn off canned cycle n170 m2 program end CHAPTER 22 CANN
157. d the feed and speed override switches are enabled the one set at the lower setting will take effect The speed and feed rates will still be synchronized In this case the speed may differ from what is programmed even if the speed override switch is set at 100 17 3 T Select Tool To select a tool program T where the T number is the carousel slot for the tool The tool is not changed until an M6 is programmed see Section 15 3 The T word may appear on the same line as the M6 or on a previous line It is OK but not normally useful if T words appear on two or more lines with no tool change The carousel may move a lot but only the most recent T word will take effect at the next tool change It is OK to program T0 no tool will be selected This is useful if you want the spindle to be empty after a tool change It is an error if e a negative T number is used e or a T number larger than the number of slots in the carousel is used 155 CHAPTER 17 OTHER CODES 156 On some machines the carousel will move when a T word is programmed at the same time ma chining is occurring On such machines programming the T word several lines before a tool change will save time A common programming practice for such machines is to put the T word for the next tool to be used on the line after a tool change This maximizes the time available for the carousel to move Chapter 18 Order of Execution The order of execution of items on a line i
158. differs from interpreters used with many other controllers which often allow these errors silently and either gouge the part or round the corner If cutter radius compensation has already been turned on it cannot be turned on again It must be turned off first then it can be turned on again It is not necessary to move the cutter between turning compensation off and back on but the move after turning it back on will be treated as a first move as described below It is not possible to change from one cutter radius index to another while compensation is on because of the combined effect of rules 4 and 11 It is also not possible to switch compensation from one side to another while compensation is on If the tool is already covering up the next XY destination point when cutter radius compensation is turned on the gouging message is given when the line of NC code which gives the point is reached In this situation the tool is already cutting into material it should not cut If a D word is programmed that is larger than the number of tool carrousel slots an error message is given In the current implementation the number of slots is 68 The error message two G Codes Used from Same Modal Group is a generic message used for many sets of G codes As applied to cutter radius compensation it means that more than one of G40 G41 and G42 appears on a line of NC code This is not allowed CHAPTER 20 TOOL FILE AND COMPENSATION First Move The a
159. direction it was going The spindle must be turning before this cycle is used It is an error if e the spindle is not turning before this cycle is executed 14 18 8 G87 Back Boring This code is currently unimplemented in EMC2 It is accepted but the behavior is undefined 14 18 9 G88 Boring Spindle Stop Manual Out This code is currently unimplemented in EMC2 It is accepted but the behavior is undefined 14 18 10 G89 Boring Dwell Feed Out The G89 cycle is intended for boring This cycle uses a P number where P specifies the number of seconds to dwell program G89 X Y Z A B C R L P 1 Preliminary motion as described above Move the Z axis only at the current feed rate to the Z position Dwell for the P number of seconds Ae N Retract the Z axis at the current feed rate to clear Z CHAPTER 14 G CODES 148 14 18 11 G90 G91 Set Distance Mode Interpretation of RS274 NGC code can be in one of two distance modes absolute or incremental To go into absolute distance mode program G90 In absolute distance mode axis numbers X Y Z A B C usually represent positions in terms of the currently active coordinate system Any exceptions to that rule are described explicitly in this Section 14 18 To go into incremental distance mode program G91 In incremental distance mode axis numbers X Y Z A B C usually represent increments from the current values of the numbers I and J numbers alw
160. dius index too big 13 Tool radius not less than arc radius with cutter radius comp 14 Two G codes used from same modal group For some of these messages additional explanation is given below Changing a tool while cutter radius compensation is on is not treated as an error although it is unlikely this would be done intentionally The radius used when cutter radius compensation was first turned on will continue to be used until compensation is turned off even though a new tool is actually being used concave corner tool does not fit concave are too small tool does not fit When cutter radius compensation is on it must be physically possible for a circle whose radius is the half the diameter given in the tool table to be tangent to the contour at all points of Figure 8 Two Cutter Radius Compensation Errors I t In both examples the line represents a contour and the circle represents the cross section of a e contour tool following the contour using cutter radius compensation tangent to one side of the path In particular the interpreter treats concave corners and concave arcs into which the circle will not fit as errors since the circle cannot be kept tangent to the contour in these situations This error detection does not limit the shapes which can be cut but it does require that the programmer specify the actual shape to be cut or path to be followed not an approximation In this respect the interpreter
161. e End Touch off Set G54 offset for active axis Left Right Jog first axis Up Down Jog second axis Pg Up Pg Dn Jog third axis Jog fourth axis O Open File Control R Reload File R Run file P Pause execution S Resume Execution ESC Stop execution Control K Clear backplot V Cycle among preset views CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 99 9 5 emctop Show EMC Status AXIS includes a program called emctop which shows some of the details of emc s state You can run this program by invoking MACHINE gt SHOW EMC STATUS Figure 9 5 EMC Status Window acceleration actual_position angular_units 1 0 ames 3 command ns5i0 Me current_line cycle_time 0 01 debug 0 echo_serial_number 11 enabled 1 estop o exec_state feedrate 9 0 file homer jeplerfarcremc2rnc_filescd ngc flood 0 qcodes 61 617 G40 Geo 690 94 G54 G49 99 664 homed 000000 id inpos q interp_state waiting interpreter_errcode o kinematics type 1 The name of each item is shown in the left column The current value is shown in the right column If the value has recently changed it is shown on a red background 9 6 mdi Text mode MDI interface AXIS includes a program called mdi which allows text mode entry of MDI commands to a running emc session You can run this program by opening a terminal and typing mdi path to emc nml Once it is running it displays the prompt MDI gt When a blank line is entered the m
162. e RS274 has evolved over time Currently there are several dialects In general each machine tool maker has been consistent within their product line but different dialects can have commands that cause quite different behavior from one machine to another More recently the language of CNC has been hidden behind or side stepped by several programming schemes that are referred to as Conversational programming languages One common feature of these kinds of programming schemes is the selection of a shape or geometry and the addition of values for the corners limits or features of that geometry The use of Computer Aided Drafting has also had an effect on the CNC programming languages Because CAD drawings are saved as a list or database of geometries and variables associated with each they are available to be interpreted into G Code These interpreters are called CAM Computer Aided Machining programs 1One machine tool manufacturer Hurco claims to have a right to the use of these programming schemes and to the use of the term conversational when used in this context CHAPTER 1 THE ENHANCED MACHINE CONTROL 3 Like the CAD converters the rise of drawing programs like Corel and the whole bunch of paint programs converters have been written that will take a bitmap or raster or vector image and turn it into G Code that can be run with a CNC You re asking yourself Why did I want to know this The answer is that the EMC2 as
163. e spindle axis by specifying some positive amount for the tool length offset This amount is normally the length of the cutting tool in use so that the controlled point is at the end of the cutting tool 12 2 4 Coordinate Linear Motion To drive a tool along a specified path a machining center must often coordinate the motion of several axes We use the term coordinated linear motion to describe the situation in which nominally each axis moves at constant speed and all axes move from their starting positions to their end positions at the same time If only the X Y and Z axes or any one or two of them move this produces motion in a straight line hence the word linear in the term In actual motions it is often not possible to maintain constant speed because acceleration or deceleration is required at the beginning and or end of the motion It is feasible however to control the axes so that at all times each axis has completed the same fraction of its required motion as the other axes This moves the tool along same path and we also call this kind of motion coordinated linear motion Coordinated linear motion can be performed either at the prevailing feed rate or at traverse rate If physical limits on axis speed make the desired rate unobtainable all axes are slowed to maintain the desired path 12 2 5 Feed Rate The rate at which the controlled point or the axes move is nominally a steady rate which may be set by the user
164. e the same as the slot number of the tool currently in the spindle It is OK for the H number to be zero an offset value of zero will be used It is an error if e the H number is not an integer is negative or is larger than the number of carousel slots To use no tool length offset program G49 It is OK to program using the same offset already in use It is also OK to program using no tool length offset if none is currently being used 14 13 G53 Move in absolute coordinates For linear motion to a point expressed in absolute coordinates program G1 G53 X Y Z A B C or use GO instead of G1 where all the axis words are optional except that at least one must be used The GO or G1 is optional if it is the current motion mode G53 is not modal and must be programmed on each line on which it is intended to be active This will produce coordinated linear motion to the programmed point If G1 is active the speed of motion is the current feed rate or slower if the machine will not go that fast If GO is active the speed of motion is the current traverse rate or slower if the machine will not go that fast It is an error if e G53 is used without GO or G1 being active e or G53 is used while cutter radius compensation is on See Section 12 6 for an overview of coordinate systems 14 14 G54 to G59 3 Select Coordinate System To select coordinate system 1 program G54 and similarly for other coordinate systems The system
165. e OGM a ee ah a he RR A EA A A Ww es me A 116 11 5 1 sis Position Displays es ssa nyans REESE a mees ene e bee eds 116 11 52 Feedrate Qvemide ooo ao tu aa PR oe wee A A ee ee 117 L153 Messana sft ek EE eR EBA A Oe A ech a 117 LLG Right CONIO irradia REE ERS ERE EES EOE 117 11 6 1 Programi Editor s Gee ca eu RA A AAA ee 117 116 2 BarckploL Display lt lt ras se aot a mate eG Ba A ee eo 118 UL TOO PASS occiso a REE dd de be ee es 118 11 6 eet Pase ua od oe we a ed we ed wa A te Se a 119 LL Meyer DENOS casco we eee IA a a aa a A da iy aa Vei aras 119 11 7 41 COMMON REYS ob hak A a a EERE as d eee ee 119 1L72 Manual Mode i esoe cab a RR A AA le ee a 120 E AMME oea sira aeaa a E a aL a a A AT a aA i ee ain pe ee 121 ILS Mib rebote Bata ee eH SRS e A AE e pa SEES edhe a Gi 121 CONTENTS x 12 return Machining Center Overview 122 12 1 Mechanical Componente se o e bee eee 122 TABLE A ed es oe A A O A Ewe De a hs ee Se eee we 122 12 12 Rotalionalaxes cocida rat RA REAR ee SY oe a 122 ool Ne o oca A A REE EEE Gaba eee ee bee eda 123 IZLA COIR ek we oe a Pk wee ae a a a ee ae 123 12 1 5 Pallet obutie e soa 248 cette mained Ba REE Re ee A ae eo 123 ALS VOOUCAIOUSel 2 6566 bee be thee AA ERED EHS RES 123 IZL Vool nanger 2 cab ebb PP oe wee A A Oe ee ee S 123 12 1 8 Messate Display i m kaor we eck ae ERA REM ee be a ee 123 12 1 9 Feed and Speed Override Switches s se sosa crase messene ee ee eee 123 12 110 Block Delete Swi
166. e and as the units for each option labeled units 23 4 2 Invert Image If no the black pixel is the lowest point and the white pixel is the highest point If yes the black pixel is the highest point and the white pixel is the lowest point 23 4 3 Normalize Image If yes the darkest pixel is remapped to black the lightest pixel is remapped to white 23 4 4 Tolerance units When a series of points are within tolerance of being a straight line they are output as a straight line Increasing tolerance can lead to better contouring performance in emc but can also remove or blur small details in the image 23 4 5 Pixel Size units One pixel in the input image will be this many units usually this number is much smaller than 1 0 For instance to mill a 2 5x2 5 inch object from a 400x400 image file use a pixel size of 00625 because 2 5 400 00625 CHAPTER 23 IMAGE TO GCODE MILLING DEPTH MAPS 190 23 4 6 Plunge Feed Rate units per minute The feed rate for the initial plunge movement 23 4 7 Feed Rate units per minute The feed rate for other parts of the path 23 4 8 Spindle Speed RPM 23 4 9 Scan Pattern Possible scan patterns are e Rows e Columns e Rows then Columns e Columns then Rows 23 4 10 Scan Direction Possible scan directions are e Positive Start milling at a low X or Y axis value and move towards a high X or Y axis value e Negative Start milling at a high
167. e has 16 channels but for this example we are using only 4 at a time Before we select any more channels we need to turn off a couple Click on the channel 2 button then click the Off button at the bottom of the Vertical box Then click on channel 3 turn if off and do the same for channel 4 Even though the channels are turned off they still remember what they are connected to and in fact we will continue to use channel 3 as the trigger source To add new channels select channel 5 and choose pin stepgen 1 dir then channel 6 and select stepgen 1 step Then click run mode Normal to start the scope and adjust the horizontal zoom to 5mS per division You should see the step pulses slow down as the velocity command channel 1 approaches zero then the direction pin changes state and the step pulses speed up again You might want to increase the gain on channel 1 to about 20m per division to better see the change in the velocity command The result should look like figure 7 11 X A HAL Oscilliscope Aak Horizontal Run Mode Trigger Zoom 5 00 mSec 4047 samples Normal e Normal Pos per div at 19 9 KHz C Single C Auto SSS TRIGGERED C stop Force Vertical Level Pos Gain Pos a i re ION l z 1 fdiv 0 000 alsje 7 8 3 10111 12 13 14 15 16f Ofset Rising Selected Channel 6 stepgen 1 step Chan Off Figure 7 11 Lookin
168. e mode to another and the mode stays active until some other command changes it implicitly or explicitly Such commands are called modal For example if coolant is turned on it stays on until it is explicitly turned off The G codes for motion are also modal If a G1 straight move command is given on one line for example it will be executed again on the next line if one or more axis words is available on the line unless an explicit command is given on that next line using the axis words or cancelling motion Non modal codes have effect only on the lines on which they occur For example G4 dwell is non modal 13 9 Modal Groups Modal commands are arranged in sets called modal groups and only one member of a modal group may be in force at any given time In general a modal group contains commands for which CHAPTER 13 LANGUAGE OVERVIEW 135 it is logically impossible for two members to be in effect at the same time like measure in inches vs measure in millimeters A machining center may be in many modes at the same time with one mode from each modal group being in effect The modal groups are shown in Table 13 2 Table 13 2 Modal Groups Modal Group Meaning Member Words Motion Group 1 GO Gl G2 G3 G33 G38 2 G80 G81 G82 G83 G84 G85 G86 G87 G88 G89 Plane selection G17 G18 G19 Distance Mode G90 G91 Feed Rate Mode G93 G94 Units G20 G21 Cutter Radius Compensation G40 G41
169. e of units to be used Possible choices are in inch imperial metric mm For systems executing in native English inch units this value shall be any one of in inch or imperial For systems executing in native millimeter units this value shall be mn or metric This does not affect the ability to program in English or metric units in NC code It is used to determine how to interpret the numbers reported in the controller status by external programs ANGULAR_UNITS lt units gt The name of units to be used For systems executing in native degree units this value should be deg or degree For systems executing in radians this value is rad or radian Another possible value is grad or gon for units operating in gradians 400 gradians in a full circle DEFAULT_VELOCITY 0 0167 The initial velocity used for axis or coordinated axis motion in user units per second The value shown is one unit per minute DEFAULT _ACCELERATION 2 0 The initial acceleration used for axis or coordinated axis motion in user units per second per second MAX VELOCITY 5 0 The maximum velocity for any axis or coordinated move in user units per second Think for a moment what this value really means in hardware terms The formula is MAX_VELOCITY 60 In this case this is 300 inches per minute MAX_ACCELERATION 20 0 The maximum acceleration for any axis or coordinated axis move in user units per second per second
170. e the L for a repeat so can t say much about that feature A typical g83 line that I would write might look like G83 X0 285 YO 00 Z 0 500 RO 2 L1 Q0 05 EMC moves to position X0 285 YO 00 at the z height before the block It then pecks its way down to Z 0 500 Each peck pulls the drill tip up to RO 2 after moving Q0 05 22 6 G84 Cycle The G84 cycle is intended for right hand tapping Preliminary motion as described above Start speed feed synchronization Move the Z axis only at the current feed rate to the Z position Stop the spindle Start the spindle counterclockwise Retract the Z axis at the current feed rate to clear Z If speed feed synch was not on before the cycle started stop it Stop the spindle Start the spindle clockwise o n OO FF ONBO CHAPTER 22 CANNED CYCLES 183 22 7 G85 Cycle The G85 cycle is intended for boring or reaming O Preliminary motion as described above 1 Move the Z axis only at the current feed rate to the Z position 2 Retract the Z axis at the current feed rate to clear Z This motion is very similar to g81 except that the tool is retracted from the hole at feedrate rather than rapid 22 8 G86 Cycle The G86 cycle is intended for boring Preliminary motion as described above Move the Z axis only at the current feed rate to the Z position Dwell for the given number of seconds Stop the spindle turning Retract the Z axis at traverse rate to clear
171. e the canned cycle block is encountered by the interpreter They move the tool into the proper location for the execution of the canned cycle itself These motions will be different depending on whether the canned cycle is to be executed using absolute distances or incremental distances These motions will also be affected by the initial position of the z axis when the canned cycle block is encountered in a program If the current Z position is below the R position the Z axis is traversed to the R position This happens only once regardless of the value of L In addition for each repeat as specified by L one or two moves are made before the rest of the cycle 1 a straight traverse parallel to the XY plane to the given XY position 2 a straight traverse of the Z axis only to the R position if it is not already at the R position 22 2 G80 G80 turns off all motion You should think of it as the off position on a rotary switch where the other positions are the different possible motion modes In the EMC interpreter G80 is one of the modal codes so any other code will replace it The result of the following lines of code is the same N1000 G90 G81 X1 Y1 Z1 5 R2 8 absolute distance canned cycle N1001 G80 turn off canned cycle motion N1002 GO X0 YO ZO turn on rapid traverse and move to coordinate home produces the same final position and machine state as N1000 G90 G81 X1 Y1 21 5 R2 8 absolute distance canned cycle N1001 GO X0 YO Z0
172. ead about your rights as a user of EMC2 and the terms under which you are allowed to distribute any modifications you may make see the full GPL at http www gnu org copyleft gpl html 1 5 How the EMC2 Works The Enhanced Machine Controller EMC2 is a lot more than just another CNC mill program It can control machine tools robots or other automated devices It can control servo motors stepper motors relays and other devices related to machine tools In this handbook we focus on only a small part of that awesome capability the minimill Figure 1 1 shows a simple block diagram showing what a typical 3 axis EMC2 system might look like This diagram shows a stepper motor system The PC running Linux as its operating system is actually controlling the stepper motor drives by sending signals through the printer port These signals pulses make the stepper drives move the stepper motors The EMC2 can also run servo motors via servo interface cards or by using an extended parallel port to connect with external control boards As we examine each of the components that make up an EMC2 system we will remind the reader of this typical machine 2some parts of EMC2 are released under the Lesser GPL LPGL which allows them to be used with proprietary software as long as certain restrictions are observed CHAPTER 1 THE ENHANCED MACHINE CONTROL 5 Figure 1 1 Typical EMC2 Controlled Machine Power supply Linux PC emc2 installed
173. ect example is a single rung ladder with a NC contact in series with a coil The contact and coil belong to the same relay If this were a conventional relay as soon as the coil is energized the contacts begin to open and de energize it That means the contacts close again etc etc The relay becomes a buzzer With a PLC if the coil is OFF and the contact is closed when the PLC begins to evaluate the rung then when it finishes that pass the coil is ON The fact that turning on the coil opens the contact feeding it is ignored until the next pass On the next pass the PLC sees that the contact is open and de energizes the coil So the relay still switches rapidly between on and off but at a rate determined by how often the PLC evaluates the rung In HAL the function is the code that evaluates the rung s In fact a HAL aware realtime version of ClassicLadder would export a function to do exactly that Meanwhile a thread is the thing that runs the function at specific time intervals Just like you can choose to have a PLC evaluate all its rungs every 10mS or every second you can define HAL threads with different periods What distinguishes one thread from another is _not_ what the thread does that is determined by which functions are connected to it The real distinction is simply how often a thread runs In EMC we might have a 15uS thread a 1mS thread and a 10mS thread These would be created based on Period ServoPeriod and Tr
174. ee 96 9 3 5 Code EMY ica mioa AA A ORE oa AOR a RA A 97 0 0 1 o eese a kaak a a Nw ee ee A 97 235 2 MDI Command s p ea noaa ew eee wha Rae be bd PG hw he we 97 9 3 53 Active Ge COdes ci a EA ea a ae ae a ee da 97 9 3 6 Peed Oyerrid lt a ipaa 26 2G SR DERM EM AAA ee eR wa ed 97 9 3 7 Spindle Speed Over s reca sarna a aa Wok dc a 98 9 3 8 JOE SPEE A ee tS oS RE te Bo Ue i a ala a a io 98 g4 Keyboard Contras co ea ia ee wee a a ee ee ae 98 2 5 emetop Show BMC Status o comicas oR REE Mo eR He a 99 9 6 mdi Text mode MDUinteriace ssc a ee 99 9 7 axis remote Send remote commands to the AXISGU l 99 9 8 hal_manualtoolchange Prompt the user to exchange tools 100 99 Python modules occ on tee aS Na ee aS wae Ge ww Co eee we 100 9 10 Using AXIS to control a CNC Lathe sa ooo mo vw waa w ee 101 9 11 Advanced configuration of AXIS s 2 ee 101 GILL Poran PIS oe a e Seek He ee me Dee oS 101 O02 The A Resource Database sss sa sua Sw le ee S 102 DIES Physical Oe wheels gt oa nsee noan we eee Pe bee a BE 103 SIS O A ce eee he ethane Dekh See Se EE EE Pee ee 103 10 Using the TKEMC Graphical Interface 104 A osa oo si GG ee ee a A aime we A we Ee Se Gi ie ee Gs 104 10 2 Gening SIGIR a REG EEE EER eae ee ees 104 10 2 1 Atypical session with TkEMC 2 eremo namena u ee 105 10 3 Elements of the TREMC window s oe so sa sa sara ess se e m ee 105 Wd UO ero rt a Pee eg ee Se a Gee ee a ae 106 10
175. el JE El El El El 3 fs da ll l3 ods gt gt pl gt gt q 2 s a jal fs E Je J El Jel fa E Figure 8 1 Parport Block Diagram 76 CHAPTER 8 HARDWARE DRIVERS 77 8 1 5 Functions e FUNCT parport lt portnum gt read Reads physical input pins of port lt portnum gt and updates HAL in and in not pins e FUNCT parport read all Reads physical input pins of all ports and updates HAL in and in not pins e FUNCT parport lt portnum gt write Reads HAL out pins of port lt portnum gt and updates that port s physical output pins e FUNCT parport write all Reads HAL out pins of all ports and updates all physical output pins The individual functions are provided for situations where one port needs to be updated in a very fast thread but other ports can be updated in a slower thread to save CPU time It is probably not a good idea to use both an a11 function and an individual function at the same time 8 1 6 Common problems If loading the module reports insmod error inserting home jepler emc2 rtlib hal_parport ko 1 Device or resource busy then ensure that the standard kernel module parport_pc is not loaded and that no other device in the system has claimed the I O ports If the module loads but does not appear to function then the port address is incorrect or the probe_parport module is
176. ent Here is an example of a line containing a comment G80 M5 stop motion Comments do not cause a machining center to do anything A comment contains a message if MSG appears after the left parenthesis and before any other printing characters Variants of MSG which include white space and lower case characters are allowed The rest of the characters before the right parenthesis are considered to be a message Messages should be displayed on the message display device Comments not containing messages need not be displayed there A comment can also be used to specify a file for the results of G38 2 probing See section 14 10 CHAPTER 13 LANGUAGE OVERVIEW 134 13 6 Repeated Items A line may have any number of G words but two G words from the same modal group see Section 13 9 may not appear on the same line A line may have zero to four M words Two M words from the same modal group may not appear on the same line For all other legal letters a line may have only one word beginning with that letter If a parameter setting of the same parameter is repeated on a line 3 15 3 6 for example only the last setting will take effect It is silly but not illegal to set the same parameter twice on the same line If more than one comment appears on a line only the last one will be used each of the other comments will be read and its format will be checked but it will be ignored thereafter It is expected
177. eps it is possible to deter mine how far the motor has turned If the load exceeds the torque capability of the motor it will skip one or more steps causing position errors TASK The module within EMC A that coordinates the overall execution and interprets the part program Tel Tk A scripting language and graphical widget toolkit with which EMC s most popular GUI s A were written World Coordinates This is the absolute frame of reference It gives coordinates in terms of a fixed reference frame that is attached to some point generally the base of the machine tool Appendix B Legal Section Handbook Copyright Terms Copyright c 2000 LinuxCNC org Permission is granted to copy distribute and or modify this document under the terms of the GNU Free Documentation License Version 1 1 or any later version published by the Free Software Foundation with no Invariant Sections no Front Cover Texts and one Back Cover Text This EMC Handbook is the product of several authors writing for linuxCNC org As you find it to be of value in your work we invite you to contribute to its revision and growth A copy of the license is included in the section entitled GNU Free Documentation License If you do not find the license you may order a copy from Free Software Foundation Inc 59 Temple Place Suite 330 Boston MA 02111 1307 B 1 GNU Free Documentation License Version 1 1 March 2000 Copyright C 2000 Free Software Foundation Inc 5
178. er or whether it is published as a printed book We recommend this License principally for works whose purpose is instruction or reference 195 APPENDIX B LEGAL SECTION 196 1 APPLICABILITY AND DEFINITIONS This License applies to any manual or other work that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License The Document below refers to any such manual or work Any member of the public is a licensee and is addressed as you A Modified Version of the Document means any work containing the Document or a portion of it either copied verbatim or with modifications and or translated into another language A Secondary Section is a named appendix or a front matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document s overall subject or to related matters and contains nothing that could fall directly within that overall subject For example if the Document is in part a textbook of mathematics a Secondary Section may not explain any mathematics The relationship could be a matter of historical connection with the subject or with related matters or of legal commercial philosophical ethical or political position regarding them The Invariant Sections are certain Secondary Sections whose titles are designated as being those of Invariant Sections in the notice that says that the Document is rele
179. ere the controller executes single lines of G code A as they are typed by the operator NIST National Institute of Standards and Technology An agency of the Department of Commerce in the United States Offsets Part Program A description of a part in a language that the controller can understand For EMC that language is RS 274 NGC commonly known as G code A Rapid Fast possibly less precise motion of the tool commonly used to move between cuts If the tool meets the material during a rapid it is probably a bad thing Real time Software that is intended to meet very strict timing deadlines Under Linux in order to meet these requirements it is necessary to install RTAI A or RTLINUX A and build the software to run in those special environments For this reason real time software runs in kernel space RTAI Real Time Application Interface see http www aero polimi it rtai http www aero polimi it rtai one of two real time extensions for Linux that EMC can use to achieve real time A performance RTLINUX See http www rtlinux org http www rtlinux org one of two real time extensions for Linux that EMC can use to achieve real time A performance RS 274 NGC The formal name for the language used by EMC A part programs A Servo Motor Servo Loop Spindle On a mill or drill the spindle holds the cutting tool On a lathe the spindle holds the workpiece Stepper Motor A type of motor that turns in fixed steps By counting st
180. es This will write all modal codes onto the message scratch pad If abort or estop is pressed during a run a set of buttons displays to the right of the text that allows the operator to shift the restart line forward or backwards If the restart line is not the last active line it will be highlighted as white letters on a blue background Caution a very slow feedrate and a finger poised over the pause button is advised during any program restart The real heart of CNC machine tool work is the auto mode Sherline s auto mode displays the typical functions that people have come to expect from the EMC Along the top are a set of buttons which control what is happening in auto mode Below them is the window that shows the part of the program currently being executed As the program runs the active line shows in white letters on a red background The first three buttons Open Run and Pause do about what you d expect Pause will stop the run right where it is The next button Resume will restart motion They are like feedhold if used this way Once Pause is pressed and motion has stopped Step will resume motion and continue it to the end of the current block Press Step again to get the motion of the next block Press Resume and the interpreter goes back to reading ahead and running the program The combination of Pause and Step work a lot like single block mode on many controllers The difference is that Pause does not let mot
181. es a minute or 3 millimeters a minute if it is working in metric mode The X1 000 assuming that the X axis started at zero means the machine should move one inch in the positive X direction You will read quite a bit more about G code in the programming chapters Figure 1 7 is a block diagram of how a personal computer running the EMC2 is used to control a machine with G code The actual G code can be sent using the MDI Machine Device Interface mode or it can be sent as a file when the machine is in Auto mode These choices are made by the operator and entered using one of the Graphical User Interfaces available with the software G code is sent to the interpreter which compares the new block with what has already been sent to it The interpreter then figures out what needs to be done for the motion and input or output systems and sends blocks of canonical commands to the task and motion planning programs 1 6 Thinking Like a Machine Operator This book will not even pretend that it can teach you to run a mill or a lathe Becoming a machinist takes time and hard work An author once said We learn from experience if at all Broken tools gouged vices and scars are the evidence of lessons taught Good part finish close tolerances and CHAPTER 1 THE ENHANCED MACHINE CONTROL 9 TKEMG TkEmc BackPlot SETUP RESE 52 0000 56 1280 10 0000 Optional Stop N6911 G0Z10 Figure 1 5 The TkEmc Graphical Interface carefu
182. es by entering one block waiting for that motion to end and then enter the next block Below the entry window there is a listing of all of the current modal codes This listing can be very handy I often forget to enter a 800 before I command a motion If nothing happens I look down there to see if g80 is in effect G80 stops any motion If it s there I remember to issue a block like g00 xO yO zO In MDI you are entering text from the keyboard so none of the main keys work for commands to the running machine F1 will Estop the control Since many of the keyboard keys are needed for entry most of the bindings that were available in auto mode are not available here 11 4 4 FEEDHOLD CONTINUE Feedhold is a toggle When the EMC is ready to handle or is handling a motion command this button shows the feedhold label on a red backgrouund If feedhold has been pressed then it will show the continue label Using it to pause motion has the advantage of being able to restart the program from where you stopped it Feedhold will toggle between zero speed and whatever feedrate override was active before it was pressed This button and the function that it activates is also bound to the pause button on most keyboards 11 4 5 ABORT The abort button stops any motion when it is pressed It also removes the motion command from the EMC No further motions are cued up after this button is pressed If you are in auto mode this button removes the rest of t
183. es the halfile named in HAL POSTGUI_HALFILE Unlike HAL HALFILE only one such file may be used 9 11 4 axisrc If it exists the contents of axisrc are executed as Python source code just before the AXIS gui is displayed The details of what may be written in the axisrc are subject to change during the development cycle The lines shown in Figure 9 10 add Control Q as a keyboard shortcut for Quit Figure 9 10 Sample axisrc file root_window bind lt Control q gt destroy help2 append Control Q Quit Chapter 10 Using the TkEMC Graphical Interface 10 1 Introduction TkEMC is one of the most traditional graphical front ends for EMC It is written in Tcl and uses the Tk toolkit for the display Being written in TCL makes it very portable runs on a multitude of platforms Figure 10 1 TKEMC Window TkEmc BackPlot file View Settings Units Scripts X Z Z SETUP RESE SPINDLE OFF BRAKE ON Tool 1 Offset 0 0000 By aes Soe TRU URE ea mm override limits relative machine y actual commanded joint word continuous home Axis Speed Feed Override 100 Spindle speed Override 100 G1 G17 G40 G21 G90 G94 G54 G49 G99 G64 G51 M2 M5 M9 M46 F225 31600 Program fhomefjuve emc2inc_files 3D_Chips ngc Status idle Open Run Pause Resume Step Verify Optional Stop N6871Y56 0612Z 28 146 N6881Y56 105Z 27 894 N6891Y56 112 27 838 N6901 Y56 1262 27 634 N6911 G0Z10
184. eter machine model uses the data items current_x and current_y to represent the position of the center of the tool tip in the currently active coordinate system at all times Jon Elson s Example All further system specific information refers to NIST s EMC program but much of it applies to most modern CNC controls My method of checking these programs is to first select tool zero which always has a diameter of zero so offset commands are essentially ignored Then I tape a sheet of paper to a piece of material that sits level in my vise as a sort of platen I install a spring loaded pen in the spindle This is a standard ballpoint pen refill cartridge made of metal in a 1 2 diameter steel housing It has a spring that loads the pen against the front and a collet at the front that allows the pen to retract against the spring but keeps it centered within a few thousandths of an inch I run the program with tool zero selected and it draws a line at the actual part s outline see figure below Then I select a tool with the diameter of the tool I intend to use and run the program again Note that Z coordinates in the program may need to be changed to prevent plunging the pen through the platen Now I get to see whether the G41 or G42 compensation that I specified will cut on the desired side of the part If it doesn t I then edit the opposite compensation command into the program and try again Now with the tool on the correct side o
185. etween feedback devices e g encoder counts and axis units e g millimeters servo gains servo and trajectory planning cycle times and other system parameters Complex kinematics for robots can be coded in C according to a prescribed interface to replace the default 3 axis Cartesian machine kinematics routines CHAPTER 1 THE ENHANCED MACHINE CONTROL 7 keystick FL Estop On Off FS HDI Mode PS Spend Fuwd OFF ESC Aborts Actions F2 Machine OnO0ff FA Reset Interp FIO Spndl Rev OFF TR Selects Params F Manual Hode Ff Hist On DFF PA Spend Decrease BM Quits Display Fa Auto Mode FB Flood On Off Fl Spndl Increase FF Toggles Help AUTO HOMED Override 100 LUBE ON ARE D Tool a LUBE Ok I Speed 60 0 Offset 0 0000 Incr continuous Relative Act Post Program Linet Command Interpreter Modal G Codes G80 619 640 620 690 694 Gh4 649 699 61 1 Modal M Codes H4 MO M46 FO S e EMC HAL SIM EHC Version 1 2 Figure 1 3 The Keystick interface 1 5 3 Discrete I O Controller EMCIO Discrete I O controllers are highly machine specific and are not customizable in general using the INI file technique used to configure the more generic motion controller However since EMC2 uses the HAL reconfiguration of the I O subsystem has become very powerful and flexible EMC2 contains a Programmable Logic Controller module behaves just like a hardware PLC that can be used for very complex scenarios tool cha
186. exclusive or and logical and If operations are strung together for example in CHAPTER 13 LANGUAGE OVERVIEW 133 the expression 2 0 3 x 1 5 5 5 11 0 operations in the first group are to be performed before operations in the second group and operations in the second group before operations in the third group If an expression contains more than one operation from the same group such as the first and in the example the operation on the left is performed first Thus the example is equivalent to 2 0 3 x 1 5 5 5 11 0 which simplifies to 1 0 0 5 which is 0 5 The logical operations and modulus are to be performed on any real numbers not just on integers The number zero is equivalent to logical false and any non zero number is equivalent to logical true 13 3 4 Unary Operation Value A unary operation value is either ATAN followed by one expression divided by another expression for example ATAN 2 1 3 or any other unary operation name followed by an expression for example SIN 90 The unary operations are ABS absolute value ACOS arc cosine ASIN arc sine ATAN arc tangent cos cosine EXP e raised to the given power FIX round down FUP round up LN natural logarithm ROUND round to the nearest whole number SIN sine SORT square root and TAN tangent Arguments to unary operations which take angle measures COS SIN and TAN are in degrees Values returned
187. f 8 7 Pico Systems PPMC Parallel Port Motion Control Pico Systems has a family of boards for doing servo stepper and pwm control The boards connect to the PC through a parallel port working in EPP mode Although most users connect one board to a parallel port in theory any mix of up to 8 or 16 boards can be used on a single parport One driver serves all types of boards The final mix of I O depends on the connected board s The driver doesn t distinguish between boards it simply numbers I O channels encoders etc starting from O on the first card Installing emc2 halcmd loadrt hal_ppmc port_addr lt addr1 gt lt addr2 gt lt addr3 gt The port_addr parameter tells the driver what parallel port s to check By default lt addr1 gt is 0x0378 and lt addr2 gt and lt addr3 gt are not used The driver searches the entire address space of the enhanced parallel port s at port_addr looking for any board s in the PPMC family It then exports HAL pins for whatever it finds During loading or attempted loading the driver prints some usefull debugging message to the kernel log which can be viewed with dmesg CHAPTER 8 HARDWARE DRIVERS 88 8 7 8 7 1 Removing emc2 halcmd unloadrt hal_ppmc 2 Pins In the following pins parameters and functions lt board gt is the board ID According to the naming conventions the first board should always have an ID of zero However this driver sets the ID based on a pair of
188. f AXIS 9 11 1 Program Filters AXIS has the ability to send loaded files through a filter program This filter can do any desired task Something as simple as making sure the file ends with M2 or something as complicated as detecting whether the input is a depth image and generating g code to mill the shape it defines The FILTER section of the ini file controls how filters work First for each type of file write a PROGRAM_EXTENSION line Then specify the program to execute for each type of file This program is given the name of the input file as its first argument and must write rs274ngc code to standard output This output is what will be displayed in the text area previewed in the display area and executed by emc when Run CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 102 FILTER PROGRAM_EXTENSION png gif Greyscale Depth Image png image to gcode py gif image to gcode py It is also possible to specify an interpreter PROGRAM_EXTENSION py Python Script py python In this way any Python script can be opened and its output is treated as g code One such example script is available at nc_files holecircle py This script creates g code for drilling a series of holes along the circumference of a circle Figure 9 9 Circular Holes Circular Holes mE Units G20 fin a Center 1 0 o Center Y 0 0 Increment Angle 17 0 Radius 1 0 Ho
189. f buttons to the right of the program display in auto mode These allow the operator to restart a program after an abort or estop These will pop in whenever estop or abort is pressed but can be shows by the operator anytime auto mode is active by selecting this menu item Hide _Restart removes the block of buttons that control the restart of a program that has been aborted or estopped Show_Split_Right changes the nature of the right hand column so that it shows both mode and pop in information Show_Mode_Full changes the right hand column so that the mode buttons or displays fill the entire right side of the screen In manual mode running with mode full you will see spindle and lube control buttons as well as the motion buttons Show_Popin Full changes the right hand column so that the popin fills the entire right side of the screen Settings These menu items allow the operator to control certain parameters during a run Actual Position sets the main position displays to actual machine based values Commanded Position sets the main position displays to the values that they were com manded to Machine Position sets the main position displays to the absolute distance from where the machine was homed Relative_Position sets the main position displays to show the current position including any offsets like part zeros that are active For more information on offsets see the chapter on coordinate systems Info lets you see a number of
190. f the work you get to see if there are any places where the tool is too fat to fit in a concave part of the surface My old Allen Bradley 7320 was pretty forgiving on this but EMC is a complete stickler If you have ANY concavity where two lines meet at less than 180 degrees on the side that a tool of finite size cuts on EMC will stop with an error message there Even if the gouge will be 0001 deep So I always make the approach on the lead in and lead out moves such that they just nip the corner of the part a tiny bit providing an angle just over 180 degrees so that EMC won t squawk This requires some careful adjustment of the starting and ending points which are not compensated by cutter radius but must be chosen with an approximate radius in mind The operative commands are G40 Cancel Cutter compensation G41 Cutter Compensation Tool Left of Path G42 Cutter Compensation Tool Right of Path Here is a short file that cuts one side of a part with multiple convex and concave arcs and several straight cuts too It is to clamp a high speed drilling spindle to the side of the main Bridgeport CHAPTER 20 TOOL FILE AND COMPENSATION 169 spindle Most of these commands are straight from Bobcad CAM but lines N15 and N110 were added by me and some of the coordinates around those lines had to be fudged a bit by me 10 G01 G40 X 1 3531 Y3 4 r10 G17 G41 D4 X 0 7 Y3 1875 COMP LEAD IN XO Y3 1875 X0 5667 F10 N15 0 0 0 G
191. figuration selector is designed to make those first test runs easier by showing the different configurations available and a bit of information about each You will probably not be able to run all of these configurations on the same computer Several require that specific hardware like the PICO Systems Universal Stepper Controller be connected or a or the Motinc Light board be installed before starting that configuration This hardware requirement is true of most all of the servo configurations There are also stepper configurations that use one or more parallel ports as well as simulators that do not require any specific hardware EMC2 starts just like most installed Linux software With a regularly installed system you can issue the command emc in most any terminal at most any location within the Linux tree If you have used a Ubuntu install you will find EMC2 under the Applications gt CNC menu Either of these methods will pop up the configuration selector Figure 3 1 shows the appearance of the configuration selector screen Move your mouse cursor over and click on any of the configurations listed in the center tree and you ll be able to read about that configuration on the right side of the screen When you ve found a configuration that you d like to try click the OK button and this script will start that configuration This script remembers the last configuration you ran so that you don t have to run through the whole list each time while tr
192. file or from the halemd prompt 74 CHAPTER 8 HARDWARE DRIVERS 75 From a file or at the halcmd prompt loadrt hal_parport cfg lt config string gt The config string consists of a hex port address followed by an optional direction repeated for each port The direction is in out or x and determines the direction of the physical pins 2 through 9 and whether to create input HAL pins for the physical control pins If the direction is not specified the data group defaults to output For example loadrt hal_parport cfg 0x278 0x378 in 0x20A0 out This example installs drivers for one port at 0x0278 with pins 2 9 as outputs by default since neither in nor out was specified one at 0x0378 with pins 2 9 as inputs and one at 0x20A0 with pins 2 9 explicitly specified as outputs Note that you must know the base address of the parallel port to properly configure the driver For ISA bus ports this is usually not a problem since the port is almost always at a well known address like 0278 or 0378 which is typically configured in the system BIOS The address for a PCI card is usally shown in lspci v in an I O ports line There is no default address if lt config string gt does not contain at least one address it is an error 8 1 2 Removing emc2 halcmd unloadrt hal _parport 8 1 3 Pins e BIT parport lt portnum gt pin lt pinnum gt out Drives a physical output pin e BIT
193. for it Installing EMC2 on it is trivial as you will see in Chapter 2 The EMC2 will not run under a Microsoft TM operating system The reason for this is that the EMC2 requires a real time environment for the proper operation of its motion planning and stepper pulse outputs Along with that it also benefits from the much needed stability and performance of the Linux OS 1 4 History of the Software The EMC code was started by the Intelligent Systems Division at the National Institute of Standards and Technology in the United States The quotation below taken from the NIST web presence some time back should lend some understanding of the essential reasons for the existence of this software and of the NIST involvement in it As part of our NIST collaboration with the OMAC User s Group we have written soft ware which implements real time control of equipment such as machine tools robots and coordinate measuring machines The goal of this software development is twofold first to provide complete software implementations of all OMAC modules for the purpose of validating application programming interfaces and second to provide a vehicle for the transfer of control technology to small and medium sized manufacturers via the NIST Manufacturing Extension Partnership The EMC software is based on the NIST Real time Control System RCS Methodology and is programmed using the NIST RCS Library The RCS Library eases the porting of controller c
194. from nuts that are loose on leadscrews slippage in belts cable slack wind up in rotary couplings and other places where the mechanical system is not tight Backlash will result in inaccurate motion or in the case of motion caused by external forces think cutting tool pulling on the work piece the result can be broken cutting tools This can happen because of the sudden increase in chip load on the cutter as the work piece is pulled across the backlash distance by the cutting tool Backlash Compensation Any technique that attempts to reduce the effect of backlash without actually removing it from the mechanical system This is typically done in software in the controller This can correct the final resting place of the part in motion but fails to solve problems related to direction changes while in motion think circular interpolation and motion that is caused when external forces think cutting tool pulling on the work piece are the source of the motion Ball Screw A type of lead screw that uses small hardened steel balls between the nut A and screw to reduce friction Ball screws have very low friction and backlash A but are usually quite expensive Ball Nut A special nut designed for use with a ball screw It contains an internal passage to re circulate the balls from one end of the screw to the other CNC Computer Numerical Control The general term used to refer to computer control of machin ery Instead of a human operator turn
195. fset to It was decided that there would only be two choices tool left of path and tool right of path This is to be interpreted as left or right when facing the direction of cutter motion The interpretation is as if you were standing on the part walking behind the tool as it progresses across the part 20 4 1 Cutter Radius Compensation Detail The cutter radius compensation capabilities of the interpreter enable the programmer to specify that a cutter should travel to the right or left of an open or closed contour in the XY plane composed of arcs of circles and straight line segments The contour may be the outline of material not to be machined away or it may be a tool path to be followed by an exactly sized tool This figure shows two examples of the path of a tool cutting using cutter radius compensation so that it leaves a triangle of material remaining In both examples the shaded triangle represents material which should remain after cutting and the line outside the shaded triangle represents the path of the tip of a cutting tool Both paths will leave the shaded triangle uncut The one on the left with rounded corners is the path the inter preter will generate In the method on the right the one not used the tool does not stay in con tact with the shaded triangle at sharp corners This way NOT This way Z axis motion may take place while the contour is being followed in the XY plane Portions of the co
196. fully milled e Secondary When milling in the second direction areas that do not strongly slope in that direction are skipped e Full When milling in the first direction areas that strongly slope in the second direction are skipped When milling in the second direction areas that do not strongly slope in that direction are skipped 23 4 17 Contact angle When Lace bounding is not None slopes greater than Contact angle are considered to be strong slopes and slopes less than that angle are considered to be weak slopes Appendix A Glossary of Common Terms Used in the EMC Documents A listing of terms and what they mean Some terms have a general meaning and several additional meanings for users installers and developers Acme Screw A type of lead screw A that uses an acme thread form Acme threads have somewhat lower friction and wear than simple triangular threads but ball screws A are lower yet Most manual machine tools use acme lead screws Axis One of the computer control movable parts of the machine For a typical vertical mill the table is the X axis the saddle is the Y axis and the quill or knee is the Z axis Additional linear axes parallel to X Y and Z are called U V and W respectively Angular axes like rotary tables are referred to as A B and C Backlash The amount of play or lost motion that occurs when direction is reversed in a lead screw A or other mechanical motion driving system It can result
197. g at Step Pulses CHAPTER 7 HAL TUTORIAL 73 Chapter 8 Hardware Drivers 8 1 Parport Parport is a driver for the traditional PC parallel port The port has a total of 17 physical pins The original parallel port divided those pins into three groups data control and status The data group consists of 8 output pins the control group consists of 4 pins and the status group consists of 5 input pins In the early 1990 s the bidirectional parallel port was introduced which allows the data group to be used for output or input The HAL driver supports the bidirectional port and allows the user to set the data group as either input or output If configured as output a port provides a total of 12 outputs and 5 inputs If configured as input it provides 4 outputs and 13 inputs In some parallel ports the control group pins are open collectors which may also be driven low by an external gate On a board with open collector control pins the x mode allows a more flexible mode with 8 dedicated outputs 5 dedicated inputs and 4 open collector pins In other parallel ports the control group has push pull drivers and cannot be used as an input No other combinations are supported and a port cannot be changed from input to output once the driver is installed Figure 8 1 shows two block diagrams one showing the driver when the data group is configured for output and one showing it configured for input The parport driver can contr
198. g the left hand side of the window Once you have selected a coordinate system you can enter values or move an axis to a teach position You can also teach using an edgefinder by adding the Figure 11 8 Mini Offset Display radius and length to the offset_by widgets When you do this you may need to add or subtract the radius depending upon which surface you choose to touch from This is selected with the add or subtract radiobuttons below the offset windows The zero all for the active coordinate system button will remove any offsets that you have showing but they are not set to zero in the variable file until you press the write and load file button as well This write and load file button is the one to use when you have set all of the axis values that you want for a coordinate system 11 7 Keyboard Bindings A number of the bindings used with tkemc have been preserved with mini A few of the bindings have been changed to extend that set or to ease the operation of a machine using this interface Some keys operate the same regradless of the mode Others change with the mode that EMC is operating in 11 7 1 Common Keys Pause Toggle feedhold Escape abort motion F1 toggle estop estop reset state CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE F2 toggle machine off machine on state F3 manual mode F4 auto mode F5 MDI mode F6 reset interpreter The following only work for machines using auxiliary I O F7 toggle mist on mist off
199. ggen component starts generating signals When the HAL is first started the thread s are not actually running This is to allow you to completely configure the system before the realtime code starts Once you are happy with the configuration you can start the realtime code like this halcmd start Now the signal generator is running Let s look at its output pins halcmd show pin Component Pins Owner Type Dir Value Name 32769 float OUT 2 12177e 01 siggen 0 cosine 32769 float OUT 5 64055e 01 siggen 0 sawtooth 32769 float OUT 9 79820e 01 siggen 0 sine 32769 float OUT 1 00000e 00 siggen 0 square 32769 float OUT 1 28110e 01 siggen 0 triangle halcmd show pin Component Pins Owner Type Dir Value Name CHAPTER 7 HAL TUTORIAL 56 32769 float OUT 5 19530e 01 siggen 0 cosine 32769 float OUT 6 73893e 01 siggen 0 sawtooth 32769 float OUT 8 54452e 01 siggen 0 sine 32769 float OUT 1 00000e 00 siggen 0 square 32769 float OUT 3 47785e 01 siggen 0 triangle We did two show pin commands in quick succession and you can see that the outputs are no longer zero The sine cosine sawtooth and triangle outputs are changing constantly The square output is also working however it simply switches from 1 0 to 1 0 every cycle 7 3 4 Changing parameters The real power of HAL is that you can change things For example we can use the setp command to set the value of a parameter Let s change the amplitude of the signal generator from 1 0 to
200. gram G81 X Y Z A B C R L 1 Preliminary motion as described above 2 Move the Z axis only at the current feed rate to the Z position 3 Retract the Z axis at traverse rate to clear Z Example 1 Suppose the current position is 1 2 3 and the XY plane has been selected and the following line of NC code is interpreted G90 G81 G98 X4 Y5 Z1 5 R2 8 This calls for absolute distance mode G90 and OLD_Z retract mode G98 and calls for the G81 drilling cycle to be performed once The X number and X position are 4 The Y number and Y position are 5 The Z number and Z position are 1 5 The R number and clear Z are 2 8 Old Zis 3 The following moves take place 1 a traverse parallel to the XY plane to 4 5 3 2 a traverse parallel to the Z axis to 4 5 2 8 3 a feed parallel to the Z axis to 4 5 1 5 4 a traverse parallel to the Z axis to 4 5 3 Example 2 Suppose the current position is 1 2 3 and the XY plane has been selected and the following line of NC code is interpreted G91 G81 G98 X4 Y5 Z 0 6 R1 8 L3 This calls for incremental distance mode G91 and OLD_Z retract mode G98 and calls for the G81 drilling cycle to be repeated three times The X number is 4 the Y number is 5 the Z number is 0 6 and the R number is 1 8 The initial X position is 5 1 4 the initial Y position is 7 2 5 the clear Z position is 4 8 1 8 3 and the Z position is 4 2 4 8 0 6 Old Z is 3 The first move is a traverse alo
201. group_id 6744 14 CHAPTER 2 INSTALLING THE EMC2 SOFTWARE 15 2 3 EMC2 Live CD The EMC2 team now has a custom Live CD based on Ubuntu 6 06 that will let you try out EMC2 before installing and it s also the easiest way to install Ubuntu and EMC2 together Just download the ISO http linuxecnc org iso emc2 ubuntu6 06 desktop i386 iso EU Mirror http dsplabs utt ro juve emc and burn it to a CD The MD5SUM of the CD is 6ee5048eb9cb424aa030dfedccc5386b When you boot the CD on your machine you can see and experiment with the exact environment and EMC2 software that you will have if you choose to install it If you like what you see just click the Install icon on the desktop answer a few questions your name timezone password and the install completes in a few minutes This install gives you all the benefits of the community supported Ubuntu distribution as well as being automatically configured for EMC2 As new Ubuntu updates or EMC2 releases are made the Update manager will let you know and allow you to easily upgrade 2 4 EMC2 install script We also provide a simple script to install emc2 on Ubuntu for users with an existing installation of Ubuntu It runs the commands explained in 2 5 To use it you need to Download the script from http www linuxcnc org emc2 install sh for Ubuntu 5 10 or http linuxcnc org dapper emc2 install sh For Ubuntu 6 06 Save it on your Desktop Right click the icon select Properties
202. gt freqgen 1 velocity The show sig command makes it clear exactly how data flows through the HAL For example the X_vel signal comes from pin siggen 0 cosine and goes to pin freqgen 0 velocity 7 5 3 Setting up realtime execution threads and functions Thinking about data flowing through wires makes pins and signals fairly easy to understand Threads and functions are a little more difficult Functions contain the computer instructions that actually get things done Thread are the method used to make those instructions run when they are needed First let s look at the functions available to us halcmd show funct Exported Functions Owner CodeAddr Arg P Users Name F 03 D89051C4 D88F10FC YES 0 siggen 0 update 02 D8902868 D88F1054 YES 0 freqgen capture_position 02 D8902498 D88F1054 NO 0 freqgen make_pulses 02 D89026F0 D88F1054 YES 0 freqgen update_freq In general you will have to refer to the documentation for each component to see what its functions do In this case the function siggen 0 update is used to update the outputs of the CHAPTER 7 HAL TUTORIAL 63 signal generator Every time it is executed it calculates the values of the sine cosine triangle and square outputs To make smooth signals it needs to run at specific intervals The other three functions are related to the step pulse generators The first one freqgen capture_position is used for position feedback It captures the val
203. he X Y R and Z numbers are absolute positions in the current coordinate system The L number is optional and represents the number of repeats L 0 is not allowed If the repeat feature is used it is normally used in incremental distance mode so that the same sequence of motions is repeated in several equally spaced places along a straight line In absolute distance mode L gt 1 means do the same cycle in the same place several times Omitting the L word is equivalent to specifying L 1 The L number is not sticky When L gt 1 in incremental mode with the XY plane selected the X and Y positions are determined by adding the given X and Y numbers either to the current X and Y positions on the first go around or to the X and Y positions at the end of the previous go around on the repetitions The R and Z positions do not change during the repeats The height of the retract move at the end of each repeat called clear Z in the descriptions below is determined by the setting of the retract mode either to the original Z position if that is above the R position and the retract mode is G98 OLD_Z or otherwise to the R position See Section 14 21 It is an error if e X Y and Z words are all missing during a canned cycle e a P number is required and a negative P number is used e an L number is used that does not evaluate to a positive integer e rotational axis motion is used during a canned cycle e inverse time feed
204. he Z axis is of course perpendicular to the XY plane the X axis to the YZ plane and the Y axis to the XZ plane CHAPTER 12 RETURN MACHINING CENTER OVERVIEW 126 12 2 11 Tool Carousel Zero or one tool is assigned to each slot in the tool carousel 12 2 12 Tool Change A machining center may be commanded to change tools 12 2 13 Pallet Shuttle The two pallets may be exchanged by command 12 2 14 Feed and Speed Override Switches The feed and speed override switches may be enabled so they work as expected or disabled so they have no effect on the feed rate or spindle speed The RS274 NGC language has one command that enables both switches and one command that disables both see Section 15 5 See Section 12 3 1 for further details 12 2 15 Path Control Mode The machining center may be put into any one of three path control modes 1 exact stop mode 2 exact path mode or 3 continuous mode with optional tolerance In exact stop mode the machine stops briefly at the end of each programmed move In exact path mode the machine follows the programmed path as exactly as possible slowing or stopping if necessary at sharp corners of the path In continuous mode sharp corners of the path may be rounded slightly so that the feed rate may be kept up but by no more than the tolerance if specified See Section 14 15 12 3 Interpreter Interaction with Switches The Interpreter interacts with several switches This section descri
205. he current coordinate system using G92 or G92 3 This offset will then apply to all nine program coordinate systems This offset may be cancelled with G92 1 or G92 2 See Section 14 19 You can make straight moves in the absolute machine coordinate system by using G53 with either GO or G1 See Section 14 13 Data for coordinate systems is stored in parameters During initialization the coordinate system is selected that is specified by parameter 5220 A value of 1 means the first coordinate system the one G54 activates a value of 2 means the second coordinate system the one G55 activates and so on It is an error for the value of parameter 5220 to be anything but a whole number between one and nine Chapter 13 Language Overview The RS274 NGC language is based on lines of code Each line also called a block may include commands to a machining center to do several different things Lines of code may be collected in a file to make a program A typical line of code consists of an optional line number at the beginning followed by one or more words A word consists of a letter followed by a number or something that evaluates to a number A word may either give a command or provide an argument to a command For example G1 X3 is a valid line of code with two words G1 is a command meaning move in a straight line at the programmed feed rate and x3 provides an argument value the value of X should be 3 at
206. he program from the motion cue It also records the number of the line that was executing when it was pressed You can use this line number to restart the program after you have cleared up the reasons for pressing it 11 4 6 ESTOP The estop button is also a toggle but it works in three possible settings CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE 116 e When Mini starts up it will show a raised button with red background with black letters that say ESTOP PUSH This is the correct state of the machine when you want to run a program or jog an axis Estop is ready to work for you when it looks like this e If you push the estop button while a motion is being executed you will see a recessed gray button that says ESTOPPED You will not be able to move an axis or do any work from the Mini gui when the estop button displays this way Pressing it with your mouse will return Mini to normal ready condition e A third view is possible here A recessed green button means that estop has been take off but the machine has not been turned on Normally this only happens when lt F1 gt estop has been pressed but lt F2 gt has not been pressed Joe Martin says When all else fails press a software ESTOP This does everything that abort does but adds in a reset so that the EMC returns to the standard settings that it wakes up on If you have an external estop circuit that watches the relevant parallel port or DIO pin a software estop
207. hen at least one space appears before words While it is permitted to insert whitespace in the middle of numbers there is no reason to do so 19 3 Prefer Center format arcs Center format arcs which use I J K instead of R behave more consistently than R format arcs particularly for included angles near 180 or 360 degrees 19 4 Put important modal settings at the top of the file When correct execution of your program depends on modal settings be sure to set them at the beginning of the part program Modes can carry over from previous programs and from the MDI commands As a good preventative measure put a line similar to the following at the top of all your programs G17 G20 G40 G49 G54 G80 G90 G94 XY plane inch mode cancel diameter compensation cancel length offset coordinate system 1 cancel motion non incremental motion feed minute mode Perhaps the most critical modal setting is the distance units If you do not include G20 or G21 then different machines will mill the program at different scales Other settings such as the return mode in canned cycles may also be important 158 CHAPTER 19 G CODE BEST PRACTICES 159 19 5 Don t put too many things on one line Ignore everything in Section 18 and instead write no line of code that is the slightest bit ambiguous Similarly don t use and set a parameter on the same line even though the semantics are well defined Exception Updating a variable to a new value su
208. hical screen to the machine operator allowing manip ulation of machine and the corresponding controlling program Home A specific location in the machine s work envelope that is used to make sure the computer and the actual machine both agree on the tool position ini file A text file that contains most of the information that configures EMC A for a particular machine Joint_Coordinates These specify the angles between the individual joints of the machine Kine matics APPENDIX A GLOSSARY OF COMMON TERMS USED IN THE EMC DOCUMENTS 194 Jog Manually moving an axis of a machine Jogging either moves the axis a fixed amount for each key press or moves the axis at a constant speed as long as you hold down the key kernel space Kinematics The position relationship between world coordinates A and joint coordinates A of a machine There are two types of kinematics Forward kinematics is used to calculate world co ordinates from joint coordinates Inverse kinematics is used for exactly opposite purpose Note that kinematics does not take into account the forces moments etc on the machine It is for positioning only Lead screw An screw that is rotated by a motor to move a table or other part of a machine Lead screws are usually either ball screws A or acme screws A although conventional triangular threaded screws may be used where accuracy and long life are not as important as low cost MDI Manual Data Input This is a mode of operation wh
209. hine position is desired 21 3 Fixture Offsets G54 G59 3 Work or fixture offset are used to make a part home that is different from the absolute machine coordinate system This allows the part programmer to set up home positions for multiple parts A typical operation that uses fixture offsets would be to mill multiple copies of parts on islands in a piece similar to figure 21 1 The values for offsets are stored in the VAR file that is requested by the INI file during the startup of an EMC In our example below we ll use G55 The values for each axis for G55 are stored as variable numbers 171 CHAPTER 21 COORDINATE SYSTEM AND G92 OFFSETS 172 G53 G54 G55 XOYO X2Y0 X4 YO O X0 YO O X0 YO for for fixture 1 fixture 2 fixture 7 fixture 8 fixture 5 fixture 6 Figure 21 1 Work Offsets 5241 0 000000 5242 0 000000 5243 0 000000 5244 0 000000 5245 0 000000 5246 0 000000 In the VAR file scheme the first variable number stores the X offset the second the Y offset and so on for all six axes There are numbered sets like this for each of the fixture offsets Each of the graphical interfaces has a way to set values for these offsets You can also set these values by editing the VAR file itself and then issuing a reset so that the EMC reads the new values For our example let s directly edit the file so that G55 takes on the following values 5241 2 000000 5242 1 000000 5243 2 000000 5244 0 000000 524
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211. if the Document is less than one quarter of the entire aggregate the Document s Cover Texts may be placed on covers that surround only the Document within the aggregate Otherwise they must appear on covers around the whole aggregate 8 TRANSLATION Translation is considered a kind of modification so you may distribute translations of the Document under the terms of section 4 Replacing Invariant Sections with translations requires special permission from their copyright holders but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections You may include a translation of this License provided that you also include the original English version of this License In case of a disagreement between the translation and the original English version of this License the original English version will prevail 9 TERMINATION You may not copy modify sublicense or distribute the Document except as expressly provided for under this License Any other attempt to copy modify sublicense or distribute the Document is void and will automatically terminate your rights under this License However parties who have received copies or rights from you under this License will not have their licenses terminated so long as such parties remain in full compliance 10 FUTURE REVISIONS OF THIS LICENSE The Free Software Foundation may publish new revised versions of the GNU Free Documentation L
212. ing emc2 realtime start emc2S halcmd kf When halcmd exits halrun stops the realtime system just like emc2 realtime stop You can also supply arguments to halrun that are passed on to halemd or give the name of a hal file Because halrun stops the realtime system when it exits the hal file run in this way will typically end with a command that waits for completion like loadrt w halscope 7 2 Tab completion Your version of halcmd may include tab completion Instead of completing filenames as a shell does it completes commands with HAL identifiers Try pressing tab after starting a HAL command halcmd lo lt TAB gt loadrt loadusr lock halcmd loadrt d lt TAB gt ddt debounce 7 3 A Simple Example 7 3 1 Loading a realtime component For the first example we will use a HAL component called siggen which is a simple signal generator A complete description of the siggen component can be found in section of this document It is a realtime component implemented as a Linux kernel module To load siggen use the halcmd loadrt command halcmd loadrt siggen 7 3 2 Examining the HAL Now that the module is loaded it is time to introduce halcmd the command line tool used to configure the HAL This tutorial will introduce some halemd features for a more complete description try man halcmd or see the halcmd reference in section of this document The first halemd feature is the show command This command displays inform
213. ing cranks to move a cutting tool CNC uses a computer and motors to move the tool based on a part program A Coordinate Measuring Machine A Coordinate Measuring Machine is used to make many accurate measurements on parts These machines can be used to create CAD data for parts where no 192 APPENDIX A GLOSSARY OF COMMON TERMS USED IN THE EMC DOCUMENTS 193 drawings can be found when a hand made prototype needs to be digitized for moldmaking or to check the accuracy of machined or molded parts DRO A Digital Read Out is a device attached to the slides of a machine tool or other device which has parts that move in a precise manner to indicate the current location of the tool with respect to some reference position Nearly all DRO s use linear quadrature encoders to pick up position information from the machine EDM EDM is a method of removing metal in hard or difficult to machine or tough metals or where rotating tools would not be able to produce the desired shape in a cost effective manner An excellent example is rectangular punch dies where sharp internal corners are desired Milling operations can not give sharp internal corners with finite diameter tools A wire EDM machine can make internal corners with a radius only slightly larger than the wire s radius A sinker EDM cam make corners with a radius only slightly larger than the radius on the corner of the convex EDM electrode EMC The Enhanced Machine Controller Initially a N
214. ion continue to the end of the current block Feedrate Override can be very handy as you approach a first cut CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE 115 Move in quickly at 100 percent throttle back to 10 and toggle between Feedhold and 10 using the pause button When you are satisfied that you ve got it right hit the zero to the right of nine and go The Verify button runs the interpreter through the code without initiating any motion If Verify finds a problem it will stop the read near the problem block and put up some sort of message Most of the time you will be able to figure out the problem with your program by reading the message and looking in the program window at the highlighted line Some of the messages are not very helpful Sometimes you will need to read a line or two ahead of the highlight to see the problem Occasionally the message will refer to something well ahead of the highlight line This often happens if you forget to end your program with an acceptable code like m2 m30 or m60 11 4 3 MDI The MDI button or lt F5 gt sets the Manual Data Input mode This mode displays a single line of text for block entry and shows the currently active modal codes for the interpreter MDI mode allows you to enter single blocks and have the interpreter execute them as if they were part of a program kind of like a one line program You can execute circles arcs lines and such You can even test sets of program lin
215. ise combine any sections entitled Acknowledgements and any sections entitled Dedications You must delete all sections entitled Endorsements 6 COLLECTIONS OF DOCUMENTS You may make a collection consisting of the Document and other documents released under this License and replace the individual copies of this License in the various documents with a single copy that is included in the collection provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects You may extract a single document from such a collection and distribute it individually under this License provided you insert a copy of this License into the extracted document and follow this License in all other respects regarding verbatim copying of that document 7 AGGREGATION WITH INDEPENDENT WORKS A compilation of the Document or its derivatives with other separate and independent documents or works in or on a volume of a storage or distribution medium does not as a whole count as a Modified Version of the Document provided no compilation copyright is claimed for the compilation Such a compilation is called an aggregate and this License does not apply to the other self contained works thus compiled with the Document on account of their being thus compiled if they are not themselves derivative works of the Document If the Cover Text requirement of section 3 is applicable to these copies of the Document then
216. it currently exists does not directly take in CAD or any image and run a machine using it The EMC2 uses a variant of the earlier CNC language named RS274NGC Next Generation Controller All of the com mands given to the EMC2 must be in a form that is recognized and have meaning to the RS274NGC interpreter This means that if you want to carve parts that were drawn in some graphical or draft ing program you will also have to find a converter that will transform the image or geometry list into commands that are acceptable to the EMC2 interpreter Several commercial CAD CAM programs are available to do this conversion At least one converter Ace has been written that carries a copyright that makes it available to the public There has been recent talk about writing a conversational or geometric interface that would allow an operator to enter programs is much the same way that several modern proprietary controls enter programs but it isn t in there yet 1 3 Computer Operating Systems The EMC2 code can be compiled on almost any GNU Linux Distribution assuming it has been patched with a real time extension In addition to the raw code some binary distributions are available The latest packages have been created around the Ubuntu GNU Linux Distribution Ubuntu is one of the distributions that is aimed at novice Linux users and has been found to be very easy to use Along with that there are lots of places around the world that offer support
217. ith hubs on the ends of each spoke These outer hubs were connected to each other with longer spokes Pd spend hours dreaming of living in such a device walking from hub to hub around the outside as it slowly rotated producing near gravity in weightless space Supplies traveled through the spokes in elevators that transfered them to an from rockets docked at the center hub while they transfered their precious cargos The idea of one pin or component being the hub for many connections is also an easy concept within the HAL Examples two and four see section 7 connect the meter and scope to signals that are intended to go elsewhere Less easy is the notion of a hub for several incoming signals but that is also possible with proper use of functions within that hub component that handle those signals as they arrive from other components Another thought that comes forward from this toy is a mechanical representation of HAL threads A thread might look a bit like a centipede caterpillar or earwig A backbone of hubs HAL components strung together with rods HAL signals Each component takes in it own parameters and input pins and passes on output pins and parameters to the next component Signals travel along the backbone from end to end and are added to or modified by each component in turn Threads are all about timing and doing a set of tasks from end to end A mechanical representation is available with Tinkertoys also when we think of the length
218. kplot is started before a program is started it will try to use some color lines to indicate the kind of motion that was used to make it A green line is a rapid move A black line is a feedrate move Blue and red indicate arcs in counterclockwise and clockwise directions The backplotter with Mini allows you to zoom and rotate views after you have run your program but it is not intended to store a tool path for a long period of time 11 6 3 Tool Page The tool page is pretty much like the others You can set length and diameter values here and they become effective when you press the Enter key You will need to set up your tool information before you begin to run a program You can t change tool offsets while the program is running or when the program is paused The Add Tools and Remove Tools buttons work on the bottom of the tool list so you will want to fill in tool information in decending order Once a new tool has been added you can use it in a program with the usual G code commands There is a 32 tool limit in the current EMC configuration files but you will run out of display space in Mini long before you get there Hint You can use menu gt view gt show popin full to see more tools if you need CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE 119 Figure 11 7 Mini Tool Display 11 6 4 Offset Page The offset page can be used to display and setup work offsets The coordinate system is selected alon
219. l or parameter as the source for channel 1 Pins Signals Parameters siggen 1 cosine siggen 1 sine siggen 1 square siggen 1 triangle stepgen 1 counts stepgen 1 dir stepgen 1 position stepgen 1 step stepgen 1 velocity stepgen 2 counts stepgen 2 dir Cancel Figure 7 6 Select Channel Source dialog To choose a signal just click on it In this case we want to use channel 1 to display the signal X_vel When we click on X_vel the dialog closes and the channel is now selected The channel 1 button is pressed in and channel number 1 and the name X_vel appear below the row of buttons That display always indicates the selected channel you can have many channels on the screen but the selected one is highlighted and the various controls like vertical position and scale always work on the selected one To add a signal to channel 2 click the 2 button When the dialog pops up click the Signals tab then click on Y_vel We also want to look at the square and triangle wave outputs There are no signals connected to those pins so we use the Pins tab instead For channel 3 select siggen 0 triangle and for channel 4 select siggen 0 square CHAPTER 7 HAL TUTORIAL 68 7 6 3 Capturing our first waveforms Now that we have several probes hooked to the HAL it s time to capture some waveforms To start the scope click the Normal button in the Run Mode
220. l and the nominal diameter used when the G code for the part was written 160 CHAPTER 20 TOOL FILE AND COMPENSATION 161 The COMMENT column may optionally be used to describe the tool Any type of description is OK This column is for the benefit of human readers only The units used for the length and diameter of the tool may be in either millimeters or inches but if the data is used by an NC program the user must be sure the units used for a tool in the file are the same as the units in effect when NC code that uses the tool data is interpreted The lines do not have to be in any particular order Switching the order of lines has no effect If the same pocket number is used on two or more lines which should not normally be done the data for only the last such line will persist and be used 20 2 Tool Compensation Tool compensation can cause problems for the best of nc code programmers But it can be a powerful aid when used to help an operator get a part to size By setting and reseting length and diameter of tools in a single tool table offsets can be made durring a production run that allow for variation in tool size or for minor deviation from the programmed distances and size And these changes can be made without the operator having to search through and cange numbers in a program file Throughout this unit you will find ocasional references to cannonical functions where these are nec essary for the reader to understand how a
221. l work are the evidence of lessons learned No machine no computer program can take the place of human experience As you begin to work with the EMC2 program you will need to place yourself in the position of operator You need to think of yourself in the role of the one in charge of a machine Itis a machine that is either waiting for your command or executing the command that you have just given it Throughout these pages we will give information that will help you become a good operator of the EMC2 mill You will need some information right up front here so that the following pages will make sense to you 1 6 1 Modes of Operation When an EMC2 is running there are three different major modes used for inputting commands These are Manual Auto and MDI Changing from one mode to another makes a big difference in the way that the EMC2 behaves There are specific things that can be done in one mode that can not be done in another An operator can home an axis in manual mode but not in auto or MDI modes An operator can cause the machine to execute a whole file full of G codes in the auto mode but not in manual or MDI In manual mode each command is entered separate In human terms a manual command might be turn on coolant or jog X at 25 inches per minute These are roughly equivalent to flipping a switch or turning the handwheel for an axis These commands are normally handled on one of the graphical interfaces by pressing a button wi
222. le Count 4 Feed Rate 8 0 Hole Depth 0 1 Dwell O no dwell 1 0 Retract Height 0 1 OK Cancel 9 11 2 The X Resource Database The colors of most elements of the AXIS user interface can be customized through the X Resource Database The sample file axis_light_background changes the colors of the backplot window to a dark lines on white background scheme and also serves as a reference for the configurable items in the display area For information about the other items which can be configured in Tk applications see the Tk manpages Because modern desktop environments automatically make some settings in the X Resource Database that adversely affect AXIS by default these settings are ignored To make the X Resource Database items override AXIS defaults include the following line in your X Resources CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 103 Axis xoptionLevel widgetDefault this causes the built in options to be created at the option level widgetDefault so that X Resources which are level userDefault can override them 9 11 3 Physical jog wheels To improve the interaction of AXIS with physical jog wheels the axis currently selected in the GUI is also reported on a pin with a name like axisui jog x Except for a short time when the active axis has just been changed exactly one of these pins is TRUE at one time and the rest are FALSE After AXIS has created these HAL pins it execut
223. lgorithm used for the first move when the first move is a straight line is to draw a straight line from the desti nation point which is tangent to a cir cle whose center is at the current point and whose radius is the radius of the tool The destination point of the tool tip is then found as the center of a circle of the same radius tangent to the tan gent line at the destination point This is shown in Figure 9 Ifthe programmed point is inside the initial cross section of the tool the circle on the left an error is signalled path of tool tip destination point of tool tip current point Second construct this line to determine the destination point programmed point First construct this line Figure 9 First Cutter Radius Compensation Move Straight A programmed center point pS end point Second construct this arc which is the path taken current point ga destination point of tool tip First construct this auxiliary arc 166 Figure 10 First Cutter Radius Compensation Move Arc If the first move after cutter radius compensation has been turned on is an arc the arc which is generated is derived from an auxiliary arc which has its center at the programmed center point passes through the programmed end point and is tangent to the cutter at its current location If the auxiliary arc cannot be constructed an error is signalled The generated arc moves the tool so tha
224. licking on any other axis display You can also change axis focus in manual mode if you press its name key on your keyboard Case is not important here Y or y will shift the focus to the Y axis A or a will shift the focus to the A axis To help you remember which axis will jog when you press the jog buttons the active axis name is displayed on them The EMC can jog move a particular axis as long as you hold the button down when it is set for continuous or it can jog for a preset distance when it is set for incremental You can also jog the active axis by pressing the plus or minus keys on the keyboard Again case is not important for keyboard jogs The two small buttons between the large jog buttons let you set which kind of jog you want When you are in incremental mode the distance buttons come alive You can set a distance by pressing it with the mouse CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE 114 You can toggle between distances by pressing i or I on the keyboard Incremental jog has an interesting and often unexpected effect If you press the jog button while a jog is in progress it will add the distance to the position it was at when the second jog command was issued Two one inch jog presses in close succession will not get you two inches of movement You have to wait until the first one is complete before jogging again Jog speed is displayed above the slider It can be set using the slider by clicking in the
225. ltage for the motor amplifier The units on the P gain are volts per user unit I 0 The integral gain for the axis servo The value multiplies the cumulative error between commanded and actual position in user units resulting in a contribution to the computed voltage for the motor amplifier The units on the I gain are volts per user unit seconds D O The derivative gain for the axis servo The value multiplies the difference between the current and previous errors resulting in a contribution to the computed voltage for the motor amplifier The units on the D gain are volts per user unit per second FFO O The O th order feedforward gain This number is multiplied by the commanded position resulting in a contribution to the computed voltage for the motor amplifier The units on the FFO gain are volts per user unit FF1 0 The Ist order feedforward gain This number is multiplied by the change in commanded position per second resulting in a contribution to the computed voltage for the motor amplifier The units on the FF1 gain are volts per user unit per second FF2 0 The 2nd order feedforward gain This number is multiplied by the change in commanded position per second per second resulting in a contribution to the computed voltage for the motor amplifier The units on the FF1 gain are volts per user unit per second per second OUTPUT_SCALE 1 000 SRefer to the the EMC2_Integrator_Manual for further information about servo syste
226. mmediately after the copyright notices a license notice giving the public permission to use the Modified Version under the terms of this License in the form shown in the Addendum below G Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document s license notice H Include an unaltered copy of this License I Preserve the section entitled History and its title and add to it an item stating at least the title year new authors and publisher of the Modified Version as given on the Title Page Ifthere is no section entitled History in the Document create one stating the title year authors and publisher of the Document as given on its Title Page then add an item describing the Modified Version as stated in the previous sentence J Preserve the network location if any given in the Document for public access to a Transparent copy of the Document and likewise the network locations given in the Document for previous versions it was based on These may be placed in the History section You may omit a network location for a work that was published at least four years before the Document itself or if the original publisher of the version it refers to gives permission K In any section entitled Acknowledgements or Dedications preserve the section s title and preserve in the section all the substance and tone of each of the contributor acknowledgements and or dedications given therein
227. ms It is likely that the absence of home switches and proper home procedures will result in very large errors in the application of g92 values if they exist in the var file Many EMC users do not have home switches in place on their machines For them home should be found by moving each axis to a location and issuing the home command When each axis is in a known location the home command will recalculate how the g92 values are applied and will produce consistent results Without a home sequence the values are applied to the position of the machine when the EMC begins to run 21 4 2 Setting G92 values There are at least two ways to set G92 values e right mouse click on position displays of tkemc will popup a window into which you can type a value e the g92 command Both of these work from the current location of the axis to which the offset is to be applied Issuing g92 x y za bc does in fact set values to the g92 variables such that each axis takes on the value associated with its name These values are assigned to the current position of the machine axis These results satisfy paragraphs one and two of the NIST document G92 commands work from current axis location and add and subtract correctly to give the current axis position the value assigned by the g92 command The effects work even though previous offsets are in So if the X axis is currently showing 2 0000 as its position a G92 x0 will set an offset of 2 0000 so that the cu
228. ms and PID control CHAPTER 5 INI CONFIGURATION 35 OUTPUT_OFFSET 0 000 These two values are the scale and offset factors for the axis output to the motor amplifiers The second value offset is subtracted from the computed output in volts and divided by the first value scale factor before being written to the D A converters The units on the scale value are in true volts per DAC output volts The units on the offset value are in volts These can be used to linearize a DAC Specifically when writing outputs the EMC first converts the desired output in quasi SI units to raw actuator values e g volts for an amplifier DAC This scaling looks like output of fset FAW z scale The value for scale can be obtained analytically by doing a unit analysis i e units are output SI units actuator units For example on a machine with a velocity mode amplifier such that 1 volt results in 250 mm sec velocity mny mm ampli fier volts output z of fset 250 sec secvolt Note that the units of the offset are in user units e g mm sec and they are pre subtracted from the sensor readings The value for this offset is obtained by finding the value of your output which yields 0 0 for the actuator output If the DAC is linearized this offset is normally 0 0 The scale and offset can be used to linearize the DACs as well resulting in values that reflect the combined effects of amplifier gain DAC non lineari
229. n is clicked or the key is pressed The available values are 1 0000 0 1000 0 0100 0 0010 0 0001 By pressing Home or the HOME key the selected axis will be homed Depending on your con figuration this may just set the axis value to be the absolute position 0 0 or it may make the machine move to a specific home location through use of home switches see section 5 4 for more information on homing By pressing Override Limits the machine will temporarily be permitted to jog outside the limits defined in the ini file Note if Override Limits is active the button will be displayed using a red colour CHAPTER 10 USING THE TKEMC GRAPHICAL INTERFACE 108 Figure 10 3 TKEMC Override Limits amp Jogging increments example override limits continuous continuous 0 0001 0 0010 a 0 0100 1 0000 10 3 5 2 The Spindle group The buttons on the first row select the direction for the spindle to rotate Counterclockwise Stopped Clockwise The buttons on the next row increase or decrease the rotation speed The checkbox on the third row allows the spindle brake to be engaged or released Depending on your machine configuration not all the items in this group may appear 10 3 5 3 The Coolant group The two buttons allow the Mist and Flood coolants to be turned on and off Depending on your machine configuration not all the items in this group may appear 10 3 6 Code Entry
230. n incremental distance mode so that the same sequence of motions is repeated in several equally spaced places along a straight line EMC allows L gt 1 in absolute distance mode to mean do the same cycle in the same place several times Omitting the L value is equivalent to specifying L 1 When L gt 1 in incremental mode the X and Y positions are determined by adding the given X and Y values either to the current X and Y positions on the first go around or to the X and Y positions at the end of the previous go around on the second and successive go arounds The R and Z positions do not change during the repeats The number of repeats of a canned cycle only works for in the block containing L word If you want to repeat a canned cycle using the repeat feature by placing a new L word on each line for which you want repeats The height of the retract move at the end of each repeat called clear Z in the descriptions below is determined by the setting of the retract_mode either to the original Z position if that is above the R position and the retract_mode is G98 OLD_Z or otherwise to the R position See G98 G99 below 22 1 Preliminary Motion Preliminary motion may be confusing on first read It should come clear as you work through the examples in G80 and G81 below Preliminary motion is a set of motions that is common to all 177 CHAPTER 22 CANNED CYCLES 178 of the milling canned cycles These motions are computed at the tim
231. nel kramer pubs RS274VGER_11 pdf Pages by Jon Elson http artsci wustl edu j melson http 206 19 206 56 diacomp htm http 206 19 206 56 lencomp htm 170 Chapter 21 Coordinate System and G92 Offsets 21 1 Introduction You have seen how handy a tool length offset can be Having this allows the programmer to ignore the actual tool length when writing a part program In the same way it is really nice to be able to find a prominent part of a casting or block of material and work a program from that point rather than having to take account of the location at which the casting or block will be held during the machining This chapter introduces you to offsets as they are used by the EMC These include e machine coordinates G53 e nine offsets G54 G59 3 e a set of global offsets G92 21 2 The Machine Position Command G53 Regardless of any offsets that may be in effect putting a G53 in a block of code tells the interpreter to go to the real or absolute axis positions commanded in the block For example g53 gO x0 yO zO will get you to the actual position where these three axes are zero You might use a command like this if you have a favorite position for tool changes or if your machine has an auto tool changer You might also use this command to get the tool out of the way so that you can rotate or change a part in a vice G53 is not a modal command It must be used on each line where motion based upon absolute mac
232. nfig is called stepper and usually it is found in etc emc2 sample configs stepper 4 2 Maximum step rate With software step generation the maximum step rate is one step per two BASE_PERIODs for step and direction output The maximum requested step rate is the product of an axis s MAX_VELOCITY and its INPUT_SCALE If the requested step rate is not attainable following errors will occur particularly during fast jogs and GO moves If your stepper driver can accept quadrature input use this mode With a quadrature signal one step is possible for each BASE_PERIOD doubling the maximum step rate The other remedies are to decrease one or more of the BASE_PERIOD setting this too low will cause the machine to become unresponsive or even lock up the INPUT_SCALE if you can select different step sizes on your stepper driver change pulley ratios or leadscrew pitch or the MAX_VELOCITY and STEPGEN_MAXVEL If no valid combination of BASE_PERIOD INPUT_SCALE and MAX VELOCITY is acceptable then hardware step generation such as with the emc2 supported Universal Stepper Controller 4 3 Pinout One of the majour flaws in EMC was that you couldn t specify the pinout without recompiling the source code EMC2 is far more flexible and now thanks to the Hardware Abstraction Layer you 23 CHAPTER 4 BASIC CONFIGURATIONS FOR A STEPPER BASED SYSTEM 24 can easily specify which signal goes where read the 6 1 section for more information about
233. ng the Z axis to 1 2 4 8 since old Z lt clear Z The first repeat consists of 3 moves CHAPTER 14 G CODES 146 1 a traverse parallel to the XY plane to 5 7 4 8 2 a feed parallel to the Z axis to 5 7 4 2 3 a traverse parallel to the Z axis to 5 7 4 8 The second repeat consists of 3 moves The X position is reset to 9 5 4 and the Y position to 12 7 5 1 a traverse parallel to the XY plane to 9 12 4 8 2 a feed parallel to the Z axis to 9 12 4 2 3 a traverse parallel to the Z axis to 9 12 4 8 The third repeat consists of 3 moves The X position is reset to 13 9 4 and the Y position to 17 12 5 1 a traverse parallel to the XY plane to 13 17 4 8 2 a feed parallel to the Z axis to 13 17 4 2 3 a traverse parallel to the Z axis to 13 17 4 8 14 18 3 G82 Drilling Cycle with Dwell The G82 cycle is intended for drilling Program G82 X Y Z A B C R L P 1 Preliminary motion as described above 2 Move the Z axis only at the current feed rate to the Z position 3 Dwell for the P number of seconds 4 Retract the Z axis at traverse rate to clear Z 14 18 4 G83 Peck Drilling The G83 cycle often called peck drilling is intended for deep drilling or milling with chip breaking The retracts in this cycle clear the hole of chips and cut off any long stringers which are common when drilling in aluminum This cycle takes a Q number which represents a delta increment along the
234. ng the part geometry which is intended to be made For the interpreter to work the tool path must be such that the tool stays in contact with the edge of the part geometry as shown on the left side of Figure 7 If a path of the sort shown on the right of Figure 7 is used in which the tool does not stay in contact with the part geometry all the time the interpreter will not be able to compensate properly when undersized tools are used For a tool path contour the value for the cutter diameter in the tool table will be a small positive number if the selected tool is slightly oversized and will be a small negative number if the tool is slightly undersized As implemented if a cutter diameter value is negative the interpreter compen sates on the other side of the contour from the one programmed and uses the absolute value of the given diameter If the actual tool is the correct size the value in the table should be zero Tool Path Contour example Suppose the diameter of the cutter currently in the spindle is 0 97 and the diameter assumed in generating the tool path was 1 0 Then the value in the tool table for the diameter for this tool should be 0 03 Here is an NC program which cuts material away from the outside of the triangle in the figure 0010 G1 X1 Y4 5 make alignment move 0020 G41 Gl Y3 5 turn compensation on and make first entry move 0030 G3 X2 Y2 5 Il make second entry move 0040 G2 X2 5 Y2 J 0 5 cut along arc at
235. nge but some of the toys that we played with as kids can be an aid to building things with the HAL 6 4 1 Tower Pm watching as my son and his six year old daughter build a tower from a box full of random sized blocks rods jar lids and such The aim is to see how tall they can make the tower The narrower the base the more blocks left to stack on top But the narrower the base the less stable the tower I see them studying both the next block and the shelf where they want to place it to see how it will balance out with the rest of the tower The notion of stacking cards to see how tall you can make a tower is a very old and honored way of spending spare time At first read the integrator may have gotten the impression that building a HAL was a bit like that It can be but with proper planning an integrator can build a stable system as complex as the machine at hand requires 6 4 2 Erector Sets What was great about the sets was the building blocks metal struts and angles and plates all with regularly spaced holes You could design things and hold them together with the little screws and nuts 1The Erector Set was an invention of AC Gilbert CHAPTER 6 INTRODUCTION 48 I got my first erector set for my fourth birthday I know the box suggested a much older age than I was Perhaps my father was really giving himself a present I had a hard time with the little screws and nuts I really needed four arms one each for the screwdriver sc
236. ngers etc In EMC2 there is only one big I O controller which provides support for all kinds of actions and hardware control All its outputs and inputs are HAL pins more on this later on so you can use only the subset that fits your hardware and is necessary for your application 1 5 4 Task Executor EMCTASK The Task Executor is responsible for interpreting G and M code programs whose behavior does not vary appreciably between machines G code programming is designed to work like a machinist might work The motion or turns of a handwheel are coded into blocks If a machinist wanted his mill to move an inch in the X direction at some feedrate he might slowly turn the handwheel five turns clockwise in 20 seconds The same machinist programming that same move for CNC might write the following block of code G1 F3 X1 000 CHAPTER 1 THE ENHANCED MACHINE CONTROL 8 EMC HAL SIM Settings Info 4 Editor W Backplot 4 Tools J Offsets A A X Y al X Z Z 3D Hide Setup x 92 0000 x 36 1280 Z 10 0000 Feed Override MESSAGES L fan N6891Y56 112 27 838 NG901Y56 1282 27 634 N691160Z310 N6931M9 pees 1m2 Figure 1 4 The Mini Graphical Interface G1 means that the machine is supposed to run at a programmed feedrate rather than at the fastest speed that it can GO is the way to command a rapid move like you would make above the work when not cutting The F3 means that it should travel at 3 inch
237. nother modal motion code soon after you may get one of the following error messages CHAPTER 22 CANNED CYCLES 179 Cannot use axis commands with G80 Coordinate setting given with G80 These should serve as a reminder that you need to write in a new motion word 22 3 G81 Cycle The G81 cycle is intended for drilling O Preliminary motion as described above 1 Move the Z axis only at the current feed rate to the Z position 2 Retract the Z axis at traverse rate to clear Z This cycle was used in the description of G80 above but is explained in detail here Example 2 Absolute Position G81 Suppose the current position is 1 2 3 and the following line of NC code is interpreted G90 G81 G98 X4 Y5 Z1 5 R2 8 This calls for absolute distance mode G90 and OLD_Z retract mode G98 and calls for the G81 drilling cycle to be performed once The X value and X position are 4 The Y value and Y position are 5 The Z value and Z position are 1 5 The R value and clear Z are 2 8 OLD_Z is 3 The following moves take place 1 a traverse parallel to the XY plane to 4 5 3 2 a traverse parallel to the Z axis to 4 5 2 8 3 a feed parallel to the Z axis to 4 5 1 5 4 a traverse parallel to the Z axis to 4 5 3 Preliminary motion XY linear more to Preliminary motion X and Y volves Rapid from old Initial position Me ve to R value 1 2 3 Z Nieto Drilling cycle Feedrate more from R to Rapid return to old
238. ntour may be skipped by retracting the Z axis above the part following the contour to the next point at which machining should be done and re extending the Z axis These skip motions may be performed at feed rate G1 or at traverse rate GO Inverse time feed rate G93 or units per minute feed rate G94 may be used with cutter radius compensation Under G94 the feed rate will apply to the actual path of the cutter tip not to the programmed contour Programming Instructions e To start cutter radius compensation program either G41 for keeping the tool to the left of the contour or G42 for keeping the tool to the right of the contour In Figure 7 for example if G41 were programmed the tool would stay left and move clockwise around the triangle and if G42 were programmed the tool would stay right and move counterclockwise around the triangle CHAPTER 20 TOOL FILE AND COMPENSATION 163 e To stop cutter radius compensation program G40 e If G40 G41 or G42 is programmed in the same block as tool motion cutter compensation will be turned on or off before the motion is made To make the motion come first the motion must be programmed in a separate previous block D Number The current interpreter requires a D number on each line that has the G41 or G42 word The value specified with D must be a non negative integer It represents the slot number of the tool whose radius half the diameter given in the tool table will be used or
239. o terms trivkins might be a gray block and xxkins might be a yellow block So the net result is that 24 HAL signals and two HAL functions are configured with no action needed by the integrator other than loading the module 24 signals are from 6 axis 2 because we have joint and cartesean 2 because we have forward and inverse kinematics Two functions because we have forward and inverse Because these HAL signals exist they can be metered or scoped or whatever for testing But because both modules know their names and know how to automatically connect them the integrator doesn t have to know or care This kind of automatic HAL configuration is possible because all kinematics modules plug in the same way 3The Lego name is a trademark of the Lego company CHAPTER 6 INTRODUCTION 50 6 5 Timing Issues In HAL Threads is going to take a major intellectual push because unlike the physical wiring models between black boxes that we have said that HAL is based upon simply connecting two pins with a hal signal falls far short of the action of the physical case True relay logic consists of relays connected together and when a contact opens or closes current flows or stops immediately Other coils may change state etc and it all just happens But in PLC style ladder logic it doesn t work that way Usually in a single pass through the ladder each rung is evaluated in the order in which it appears and only once per pass A perf
240. ocument CHAPTER 7 HAL TUTORIAL XA HAL Oscilliscope BAE Horizontal zoom Selected Channel Pos Run Mode Trigger 500 mSec 4047 samples C Normal per div at 994 Hz C Single E IDLE a Stop Vertical Gain Pos Normal C Auto Force Level Pos alelslals 6 7 el shomhehalialisiis Chan Off Scale Offset Level Rising Source None Figure 7 5 Initial scope window 66 CHAPTER 7 HAL TUTORIAL 67 7 6 2 Hooking up the scope probes At this point Halscope is ready to use We have already selected a sample rate and record length so the next step is to decide what to look at This is equivalent to hooking virtual scope probes to the HAL Halscope has 16 channels but the number you can use at any one time depends on the record length more channels means shorter records since the memory available for the record is fixed at approximately 16 000 samples The channel buttons run across the bottom of the halscope screen Click button 1 and you will see the Select Channel Source dialog figure 7 6 This dialog is very similar to the one used by Halmeter We would like to look at the signals we defined earlier so we click on the Signals tab and the dialog displays all of the signals in the HAL only two for this example gt lt Select Channel Source x Select a pin signa
241. ode to a variety of Unix and Microsoft platforms providing a neutral application programming interface API to operating sys tem resources such as shared memory semaphores and timers The RCS Library also implements a communication model the Neutral Manufacturing Language which allows control processes to read and write C data structures throughout a single homogeneous environment or a heterogeneous networked environment The EMC software is written in C and C and has been ported to the PC Linux Windows NT and Sun Solaris operating CHAPTER 1 THE ENHANCED MACHINE CONTROL 4 systems When running actual equipment a real time version of Linux is used to achieve the deterministic computation rates required 200 microseconds is typical The software can also be run entirely in simulation down to simulations of the machine motors This enables entire factories of EMC machines to be set up and run in a computer integrated manufacturing environment EMC has been installed on many machines both with servo motors and stepper motors Here is a sampling of the earliest applications e 3 axis Bridgeport knee mill at Shaver Engineering The machine uses DC brush servo motors and encoders for motion control and OPTO 22 compatible I O interfaced to the PC parallel port for digital I O to the spindle coolant lube and e stop systems e 3 axis desktop milling machine used for prototype development The machine uses DC brush servo motors and enc
242. oders Spindle control is accomplished using the 4th motion control axis The machine cuts wax parts e 4 axis Kearney amp Trecker horizontal machining center at General Motors Powertrain in Pontiac MI This machine ran a precursor to the full software EMC which used a hardware motion control board After these early tests Jon Elson found the Shaver Engineering notes and replaced a refrigera tor sized Allen Bradley 7300 control on his Bridgeport with the EMC running on a Red Hat 5 2 distribution of Linux He was so pleased with the result that he advertised the software on sev eral newsgroups He continues to use that installation and has produced several boards that are supported by the software From these early applications news of the software spread around the world It is now used to con trol many different kinds of machines More recently the Sherline company http www sherline com has released their first CNC mill It uses a standard release of the EMC The source code files that make up the controller are kept in a repository on http cvs linuxcnc org They are available for anyone to inspect or download The EMC2 source code with a few ex ceptions is released under the GNU General Public License GPL The GPL controls the terms under which EMC2 can be changed and distributed This is done in order to protect the rights of people like you to use study adapt improve and redistribute it freely now and in the future To r
243. odes of the RS274 NGC language are shown in Table 5 and described following that In the command prototypes the hypen stands for a real value As described earlier a real value may be 1 an explicit number 4 for example 2 an expression 2 2 for example 3 a parameter value 88 for example or 4 a unary function value acos 0 for example In most cases if axis words any or all of X Y Z A B C are given they specify a destination point Axis numbers are in the currently active coordinate system unless explicitly described as being in the absolute coordinate system Where axis words are optional any omitted axes will have their current value Any items in the command prototypes not explicitly described as optional are required It is an error if a required item is omitted In the prototypes the values following letters are often given as explicit numbers Unless stated otherwise the explicit numbers can be real values For example G10 12 could equally well be written G 2 5 L 1 1 If the value of parameter 100 were 2 G10 L 100 would also mean the same Using real values which are not explicit numbers as just shown in the examples is rarely useful If L is written in a prototype the will often be referred to as the L number Similarly the in H may be called the H number and so on for any other letter 14 1 GO Rapid Linear Motion For rapid linear motion program GO X
244. oe ee lt lt a meses 1 53 Discrete 1 0 Controller EMGIO lt ssa 6s ek eA Re Rw A 1 5 4 Task Executor EMCTASK gt c oco bb a ede e a ee Thinking Like a Machine Operator os se ew ee Ea 1 6 1 Modes oF Operation cu a AAA ROW ee Ge oe AG a a A 1 6 2 Information Display gt es 454654 56 e BER ede ee ee tes Thanking Like An Iterator coros oe he ek ee ww ES ee Be a Lel UDR G 2 Da e AA A AO A i aa Se es Ge A 1 7 2 Some things we may not want to change o o 1 73 Some things we will need to change ooo a 2 Installing the EMC2 software 2 1 2 2 2 3 2 4 2 5 CUPOCUCIOA a a RA AA A DE A oh a ds EMC Download Page ooo so kaiara a OS w e A e eee 4 EMC2 LIVE CD o cc A a e A E gt e ek kw one EY Eek SE we hk Slee he ad Eee wk Manual installing using apt commands 0 00 00 e eee eae II Configuring EMC2 3 Running EMC2 3 1 Configuration Selector c ra esa a a a we ada ee a G ii 10 11 12 12 12 14 14 14 15 15 15 17 18 CONTENTS 3 2 Copying Sample Configurations 3 2 1 Copy and Paste ooo osos 3 2 2 Drag and Drop 3 2 3 Comand Line Copy 3 3 Starting a Custom Configuration Basic configurations for a stepper based system 4 1 Introduction 2 sos ca ee aaa 4 2 Maximum step rate Moe POUE ATI 4 3 1 standard_pinout hal 4 3 2 Overview of the standard_pinout hal 4 3 3 Changing the standard_pinout h
245. of the toy as a measure of the time taken to get from one end to the other A very different thread or backbone is created by connecting the same set of hubs with different length rods The total length of the backbone can be changed by the length of rods used to connect the hubs The order of operations is the same but the time to get from beginning to end is very diferent 2Tinkertoy is now a registered trademark of the Hasbro company CHAPTER 6 INTRODUCTION 49 6 4 4 A Lego Example When Lego blocks first arrived in our stores they were pretty much all the same size and shape Sure there were half sized one and a few quarter sized as well but that rectangular one did most of the work Lego blocks interconnected by snapping the holes in the underside of one onto the pins that stuck up on another By overlapping layers the joints between could be made very strong even around corners or tees I watched my children and grandchildren build with legos the same legos There are a few thousand of them in an old ratty but heavy duty cardboard box that sits in a corner of the recreation room It stays there in the open because it was too much trouble to put the box away and then get it back out for every visit and it is always used during a visit There must be Lego parts in there from a couple dozen different sets The little booklets that came with them are long gone but the magic of building with interlocking pieces all the same size i
246. oint It is an error if e When the arc is projected on the selected plane the distance from the current point to the center differs from the distance from the end point to the center by more than 0 0002 inch if inches are being used or 0 002 millimeter if millimeters are being used When the XY plane is selected program G2 X Y Z A B C I J or use G3 instead of G2 The axis words are all optional except that at least one of X and Y must be used I and J are the offsets from the current location in the X and Y directions respectively of the center of the circle I and J are optional except that at least one of the two must be used It is an error if e X and Y are both omitted e or I and J are both omitted When the XZ plane is selected program G2 X Y Z A B C I K or use G3 instead of G2 The axis words are all optional except that at least one of X and Z must be used I and K are the offsets from the current location in the X and Z directions respectively of the center of the circle I and K are optional except that at least one of the two must be used It is an error if e X and Z are both omitted e orland K are both omitted When the YZ plane is selected program G2 X Y Z A B C J K or use G3 instead of G2 The axis words are all optional except that at least one of Y and Z must be used J and K are the offsets from the current location in the Y and Z directions respectively of the center
247. ol up to 8 ports defined by MAX_PORTS in hal_parport c The ports are numbered starting at zero 8 1 1 Installing From command line emc2 halcmd loadrt hal _parport cfg lt config string gt HAL cannot automatically determine if the x mode bidirectional pins are actually open collectors OC If they are not they cannot be used as inputs and attempting to drive them LOW from an external source can damage the hardware To determine whether your port has open collector pins load hal_parport in x mode output a HIGH value on the pin HAL should read the pin as TRUE Next insert a 470X resistor from one of the control pins to GND If the resulting voltage on the control pin is close to OV and HAL now reads the pin as FALSE then you have an OC port If the resulting voltage is far from OV or HAL does not read the pin as FALSE then your port cannot be used in x mode The external hardware that drives the control pins should also use open collector gates e g 74LS05 Generally the out HAL pins should be set to TRUE when the physical pin is being used as an input On some machines BIOS settings may affect whether x mode can be used SPP mode is most most likely to work The single quotes around the entire cfg argument are needed to prevent the shell from misinterpreting the double quotes around the string and any spaces or special characters in the string Single quotes should not be used in a
248. ollowing errors will always be present due to limited position resolution vibration etc CHAPTER 5 INI CONFIGURATION 34 UNITS inch Historically the UNITS were specified for each axis It is now preferable to specify the TRAJ LINEAR_UNITS and TRAJJANGULAR_UNITS values only and have no AXIS_n JUNITS setting 5 3 7 1 Homing related items The next few parameters are Homing related for a better explanation read Section 5 4 HOME_OFFSET 0 0 The axis position of the home switch or index pulse HOME SEARCH VEL 0 0 A value of zero means assume that the current location is the home position for the machine If your machine has no home switches you will want to leave this value alone HOME_LATCH_VEL 0 0 This is the final velocity to be used during a home sequence HOME_USE_INDEX NO If the encoder used for this axis has an index pulse and the motion card has provision for this signal you may set it to yes When it is yes it will affect the kind of home pattern used HOME_IGNORE_LIMITS NO Some machines use a limit switch as a home switch This variable should be set to yes if you machine does this 5 3 7 2 Servo related items The following items are for servo based systems and servo like systems including the univstep board from Pico Systems P 50 The proportional gain for the axis servo This value multiplies the error between commanded and actual position in user units resulting in a contribution to the computed vo
249. ook closely at part of a waveform you can use the zoom slider at the top of the screen to expand the waveforms horizontally and the position slider to determine which part of the zoomed waveform is visible However sometimes simply expanding the waveforms isn t enough and you need to increase the sampling rate For example we would like to look at the actual step pulses that are being generated in our example Since the step pulses may be only 50uS long sampling at 1KHz isn t fast enough To change the sample rate click on the button that displays the record length and sample rate to bring up the Select Sample Rate dialog figure For this example we will click on the 50uS thread fast which gives us a sample rate of about 20KHz Now instead of displaying about 4 seconds worth of data one record is 4000 samples at 20KHz or about 0 20 seconds XA Select Sample Rate x Select a thread name and multiplier then click OK or Click Quit to exit HALSCOPE Thread stepgen thread Sample Period 50 3 uSec Sample Rate 19 9 KHz Thread Period siggenthread 1 01 mSec stepgenthread 50 3 uSec Multiplier 1 Record Length C 16191 samples 1 channel C 8095 samples 2 channels 4047 samples 4 channels C 2023 samples 8 channels C 1011 samples 16 channels OK Quit Figure 7 10 Sample Rate Dialog CHAPTER 7 HAL TUTORIAL 72 7 6 7 More Channels Now let s look at the step pulses Halscop
250. op N6571Y56 0612 28 146 N6661 Y56 1052 27 694 N6891Y56 112 27 638 N6901 Y56 1262 27 634 N6911G0210 H6931 M9 10 3 4 Automatic control 10 3 4 1 Buttons for control The buttons in the lower part of TKEMC seen in Figure 10 2 are used to control the execution of a program Open to load a program Verify to check it for errors Run to start the actual cutting Pause to stop it while running Resume to resume an already paused program Step to advance one line in the program and Optional Stop to toggle the optional stop switch if the button is green the program execution will be stopped on any M1 encountered 10 3 4 2 Text Program Display Area When the program is running the line currently being executed is highlighted in white The text display will automatically scroll to show the current line 10 3 5 Manual Control 10 3 5 1 Implicit keys TKEMC allows you to manually move the machine This action is known as jogging First select the axis to be moved by clicking it Then click and hold the or button depending on the desired direction of motion The first four axes can also be moved by the arrow keys X and Y PAGE UP and PAGE DOWN keys Z and the and keys A If Continuous is selected the motion will continue as long as the button or key is pressed If another value is selected the machine will move exactly the displayed distance each time the butto
251. opy with Now you can move into the copied folder and begin to specific files to suit your specific machine To edit one of the files e g sim ini right click it and choose Open with Text Editor Details of the configuration files are in the next chapters 3 2 2 Drag and Drop To copy via dragging instead of cut amp paste e From Places choose Home Folder e From File choose Create Folder e Enter the name emc2 e click emc2 e From File choose Create Folder e Enter the name configs double click configs Now you have one copy of the file browser showing the empty configs folder Leave this browser on the screen and create another e From Places choose Computer e click Filesystem e click etc e click emc2 e click sample configs Hold down Ctrl and drag sim from this window to the window configs If you do not hold down Ctrl you will get an error that a folder could not be removed because the user can t make changes to the etc emc2 sample configs folder CHAPTER 3 RUNNING EMC2 21 3 2 3 Comand Line Copy To copy using the unix shell Open a terminal window and type mkdir p emc2 configs cp R etc emc2 sample configs stepper emc2 configs Youll find the unix terminal under the Applications menu and Accessories Figure 3 2 Terminal Window sub menu As you gain more experi ence with Linux you will find your self using this terminal to enter com File Edit View Te
252. or a material edge contour the value for the diameter in the tool table is the actual value of the diameter of the tool The value in the table must be positive The NC code for a material edge contour is the same regardless of the actual or intended diameter of the tool Example 1 Here is an NC program which cuts material away from the outside of the triangle in figure above In this example the cutter compensation radius is the actual radius of the tool in use which is 0 5 The value for the diameter in the tool table is twice the radius which is 1 0 N0010 G41 Gl X2 Y2 turn compensation on and make entry move N0020 Y 1 follow right side of triangle N0030 X 2 follow bottom side of triangle CHAPTER 20 TOOL FILE AND COMPENSATION 164 N0040 X2 Y2 follow hypotenuse of triangle N0050 G40 turn compensation off This will result in the tool following a path consisting of an entry move and the path shown on the left going clockwise around the triangle Notice that the coordinates of the triangle of material appear in the NC code Notice also that the tool path includes three arcs which are not explicitly programmed they are generated automatically Tool Path Contour When the contour is a tool path contour the path is described in the NC program It is expected that except for during the entry moves the path is intended to create some part geometry The path may be generated manually or by a post processor consideri
253. or by arrangement made by the same entity you are acting on behalf of you may not add another but you may replace the old one on explicit permission from the previous publisher that added the old one The author s and publisher s of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version 5 COMBINING DOCUMENTS You may combine the Document with other documents released under this License under the terms defined in section 4 above for modified versions provided that you include in the combination all of the Invariant Sections of all of the original documents unmodified and list them all as Invariant Sections of your combined work in its license notice APPENDIX B LEGAL SECTION 198 The combined work need only contain one copy of this License and multiple identical Invariant Sections may be replaced with a single copy If there are multiple Invariant Sections with the same name but different contents make the title of each such section unique by adding at the end of it in parentheses the name of the original author or publisher of that section if known or else a unique number Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work In the combination you must combine any sections entitled History in the various original documents forming one section entitled History likew
254. or on any line after the previous tool change will be in the spindle The T number is an integer giving the changer slot of the tool not its id If the selected tool was not in the spindle before the tool change the tool that was in the spindle if there was one will be in its changer slot The coordinate axes will be stopped in the same absolute position they were in before the tool change but the spindle may be re oriented No other changes will be made For example coolant will continue to flow during the tool change unless it has been turned off by an M9 The tool change may include axis motion while it is in progress It is OK but not useful to program a change to the tool already in the spindle It is OK if there is no tool in the selected slot in that case the spindle will be empty after the tool change If slot zero was last selected there will definitely be no tool in the spindle after a tool change 15 4 M7 M8 M9 Coolant Control To turn mist coolant on program M7 To turn flood coolant on program M8 To turn all coolant off program M9 It is always OK to use any of these commands regardless of what coolant is on or off 15 5 M48 M49 Override Control To enable the spindle speed and feedrate override switches program M48 To disable both switches program M49 See Section 12 3 1 for more details It is OK to enable or disable the switches when they are already enabled or disabled These switches can also be
255. other the user can determine the state of the input 8 3 4 Parameters e BIT ax5214 lt boardnum gt out lt pinnum gt invert Inverts an output pin The invert parameter determines whether an output pin is active high or active low If invert is FALSE setting the HAL out pin TRUE drives the physical pin low turning ON an attached OPTO 22 module and FALSE drives it high turning OFF the OPTO 22 module If invert is TRUE then setting the HAL out pin TRUE will drive the physical pin high and turn the module OFF 4The single quotes around the entire cfg argument are needed to prevent the shell from misinterpreting the double quotes around the string and any spaces or special characters in the string Single quotes should not be used in a file or from the halemd prompt CHAPTER 8 HARDWARE DRIVERS 79 8 3 5 Functions e FUNCT ax5214 lt boardnum gt read Reads all digital inputs on one board e FUNCT ax5214 lt boardnum gt write Writes all digital outputs on one board 8 4 Servo To Go The Servo To Go is one of the first PC motion control cards supported by EMC It is an ISA card and it exists in different flavours all supported by this driver The board includes up to 8 channels of quadrature encoder input 8 channels of analog input and output 32 bits digital I O an interval timer with interrupt and a watchdog 8 4 1 Installing emc2 halcmd loadrt hal_stg base lt address gt num_chan lt nr gt
256. others For more information on one of these modules use pydoc lt module name gt or read the source code These modules include e emc provides access to the emc command status and error channels e gcode provides access to the rs274ngc interpreter e rs274 provides additional tools for working with rs274ngc files e hal allows the creation of userspace HAL components written in Python e _togl provides an OpenGL widget that can be used in Tkinter applications e minigl provides access to the subset of OpenGL used by AXIS To use these modules in your own scripts you must ensure that the directory where they reside is on Python s module path When running an installed version of emc2 this should happen auto matically When running in place this can be done by using scripts emc environment CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 101 9 10 Using AXIS to control a CNC Lathe By including the line DISPLAY LATHE 1 in the ini file AXIS selects lathe mode The Y axis is not shown in coordinate readouts the view is changed to show the Z axis extending to the right and the X axis extending towards the bottom of the screen and several controls such as those for preset views are removed Pressing V zooms out to show the entire file if one is loaded When in lathe mode the shape of the loaded tool if any is shown Figure 9 8 Lathe Mode showing the lathe tool shape 9 11 Advanced configuration o
257. ottom of the screen and is displayed below the sliders The position is the location of the trigger point within the overall record With the slider all the way down the trigger point is at the end of the record and halscope displays what happened before the trigger point When the slider is all the way up the trigger point is at the beginning of the record displaying what happened after it was triggered The trigger point is visible as a vertical line in the progress box above the screen The trigger polarity can be changed by clicking the button just below the trigger level display Note that changing the trigger position stops the scope once the position is adjusted you restart the scope by clicking the Normal button in the Run Mode box Now that we have adjusted the vertical controls and triggering the scope display looks something like figure 7 9 CHAPTER 7 HAL TUTORIAL XA HAL Oscilliscope ETE Horizontal Run Mode Trigger Zoom 500 mSec 4047 samples Normal e Normal Pos per div at 994 Hz C Single C Auto TRIGGERED Stop ENS gt vertical Level Pos E Gain Pos NANA y 1 Scale Level fs NA 500mfdiw 0 000 Mizla 4 5 lef 7 8 3 10 11 12 13 14 15 16 onset Rising Selected Channel 0 000 2 Y_vel Chan Off Source Chan 3 Figure 7 9 Waveforms with Triggering CHAPTER 7 HAL TUTORIAL 71 7 6 6 Horizontal Adjustments To l
258. plane Any of the three planes XY YZ ZX may be selected Throughout this section most of the descriptions assume the XY plane has been selected The behavior is always analogous if the YZ or XZ plane is selected Rotational axis words are allowed in canned cycles but it is better to omit them If rotational axis words are used the numbers must be the same as the current position numbers so that the rotational axes do not move All canned cycles use X Y R and Z numbers in the NC code These numbers are used to determine X Y R and Z positions The R usually meaning retract position is along the axis perpendicular to the currently selected plane Z axis for XY plane X axis for YZ plane Y axis for XZ plane Some canned cycles use additional arguments For canned cycles we will call a number sticky if when the same cycle is used on several lines of code in a row the number must be used the first time but is optional on the rest of the lines Sticky numbers keep their value on the rest of the lines if they are not explicitly programmed to be different The R number is always sticky CHAPTER 14 G CODES 144 In incremental distance mode when the XY plane is selected X Y and R numbers are treated as increments to the current position and Z as an increment from the Z axis position before the move involving Z takes place when the YZ or XZ plane is selected treatment of the axis words is analogous In absolute distance mode t
259. produce relative rotation of the workpiece and the tool around an axis These mechanisms often a rotary table on which the workpiece is mounted or a drum on which the spindle is mounted are called rotational axes and labelled A B and C The A axis is parallel to the X axis B is parallel to the Y axis and C parallel to the Z axis Each rotational mechanism may or may not have a mechanical limit on how far it can rotate Uf the motion of mechanical components is not independent as with hexapod machines the RS274 NGC language and the canonical machining functions will still be usable as long as the lower levels of control know how to control the actual mechanisms to produce the same relative motion of tool and workpiece as would be produced by independent axes 2The requirement of parallelism is not used by either language so both languages are usable if any rotational axis is not parallel to any linear axis Rotational axis commands flow through both languages to lower levels of control without significant change in nature 122 CHAPTER 12 RETURN MACHINING CENTER OVERVIEW 123 12 1 3 Spindle A machining center has a spindle which holds one cutting tool probe or other item The spindle can rotate in either direction and it can be made to rotate at a constant rate which may be changed Except on machines where the spindle may be moved by moving a rotational axis the axis of the spindle is kept parallel to the Z axis and is coinciden
260. pup new windows for each thing that an operator might want to do Mini allows you to display these within the regular screen Parts of this chapter are copied from the instructions that were written for that mill by Joe Martin and Ray Henry Much of this chapter quotes from a chapater of the Sherline CNC operators manual 110 CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE 111 11 2 Screen layout BE a A a IS Program Viaw Settings Info 4 Editor E Backplot 4 Tools 4 Offeats Help A A x 0 0000 anny AS Y 0 0000 Z 0 0000 Faad Overrida 100 mm MESSAGES Figure 11 2 Mini Display for a Running EMC The Mini screen is laid out in several sections See Figure1l11 1 These include a menu across the top a set of main control buttons just below the menu and two rather large columns of information that show the state of your machine and allow you to enter commands or programs When you compare figure11 1 with figure 11 2 you will see many differences In the second figure e each axis has been homed the display numbers are dark green e the EMC mode is auto the auto button has a light green background e the backplotter has been turned on backplot is visible in the pop in window e the tool path from the program is showing in the display Once you start working with Mini you will quickly discover how easily it shows the conditions of the EMC and allows you to make changes to it 11 3 Menu Ba
261. r The first row is the menu bar across the top Here you can configure the screen to display additional information Some of the items in this menu are very different from what you may be acustomed to with other programs You should take a few minutes and look under each menu item in order to familiarize yourself with the features that are there The menu includes each of the following sections and subsections CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE 112 Program This menu includes both reset and exit functions Reset will return the EMC to the condition that it was in when it started Some startup configuration items like the normal program units can be specified in the ini file View This menu includes several screen elements that can be added so that you can see additional information during a run These include Position_Type This menu item adds a line above the main position displays that shows whether the displays are in inches or metric and whether they are Machine or Relative location and if they are Actual positions or Commanded positions These can be changed using the Settings menu described below Tool_Info This adds a line immediately below the main position displays that shows which tool has been selected and the length of offset applied Offset_Info adds a line immediately below the tool info that shows what offsets have been applied This is a total distance for each axis from machine zero Show_Restart adds a block o
262. r Real Time Application Programming Interface Many HAL components work in realtime and all HAL components store data in shared memory so realtime components can access it Normal Linux does not support realtime programming or the type of shared memory that HAL needs Fortunately there are realtime operating systems RTOS s that provide the neccessary extensions to Linux Unfortunately each RTOS does things a little differently To address these differences the EMC team came up with RTAPI which provides a consistent way for programs to talk to the RTOS If you are a programmer who wants to work on the internals of EMC you may want to study emc2 src rtapi rtapi h to understand the API But if you are a normal person all you need to know about RTAPI is that it and the RTOS needs to be loaded into the memory of your computer before you do anything with HAL For this tutorial we are going to assume that you have successfully compiled the emc2 source tree In that case all you need to do is load the required RTOS and RTAPI modules into memory Just run the following command emc2S halrun halcmd 52 CHAPTER 7 HAL TUTORIAL 53 With the realtime OS and RTAPI loaded we can move into the first example Notice that the prompt has changed from the shell s to halemd This is because subsequent commands will be interpreted as HAL commands not shell commands halrun is a simple shell script and it is more or less equivalent to runn
263. radio boxes on the right If the position is Ma chine then the displayed number is in the machine coordinate system If it is Relative then the displayed number is in the offset coordinate system Further down the choices can be actual or commanded Actual refers to the feedback coming from encoders if you have a servo machine and the commanded refers to the position command send out to the motors These values can dif fer for several reasons Following error deadband encoder resolution or step size For instance if you command a movement to X 0 0033 on your mill but one step of your stepper motor is 0 00125 then the Commanded position will be 0 0033 but the Actual position will be 0 0025 2 steps or 0 00375 3 steps Another set of radio buttons allows you to choose between joint and world view These make little sense on a normal type of machine e g trivial kinematics but helps on machines with non trivial kinematics like robots or stewart platforms you can read more about kinematics in the Integrators Handbook 10 3 3 1 Backplot When the machine moves it leaves a trail called the backplot You can start the backplot window by selecting View gt Backplot CHAPTER 10 USING THE TKEMC GRAPHICAL INTERFACE 107 Figure 10 2 TKEMC Interpreter program control Program fhome juvefemc2inc_files 3D_Chips ngc Status idle Open Run Pause Resume Step Verify Optional St
264. red that you contact the authors of the Document well before redistributing any large number of copies to give them a chance to provide you with an updated version of the Document 4 MODIFICATIONS You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above provided that you release the Modified Version under precisely this License with the Modified Version filling the role of the Document thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it In addition you must do these things in the Modified Version A Use in the Title Page and on the covers if any a title distinct from that of the Document and from those of previous versions which should if there were any be listed in the History section of the Document You may use the same title as a previous version if the original publisher of that version gives permission B List on the Title Page as authors one or more persons or entities responsible for authorship of the modifications in the Modified Version together with at least five of the principal authors of the Document all of its principal authors if it has less than five C State on the Title page the name of the publisher of the Modified Version as the publisher D Preserve all the copyright notices of the Document E Add an appropriate copyright notice for your modifications adjacent to the other copyright notices F Include i
265. rew parts to be bolted together and nut Perseverence along with father s eventual boredom got me to where I had built every project in the booklet Soon I was lusting after the bigger sets that were also printed on that paper Working with those regular sized pieces opened up a world of construction for me and soon I moved well beyond the illustrated projects Hal components are not all the same size and shape but they allow for grouping into larger units that will do useful work In this sense they are like the parts of an Erector set Some components are long and thin They essentially connect high level commands to specific physical pins Other components are more like the rectangular platforms upon which whole machines could be built An integrator will quickly get beyond the brief examples and begin to bolt together components in ways that are unique to them 6 4 3 Tinkertoys Wooden Tinker toys had a more humane feel that the cold steel of Erector Sets The heart of construction with Tinker Toys was a round connector with eight holes equally spaced around the circumference It also had a hole in the center that was perpendicular to all the holes around the hub Hubs were connected with rods of several different lengths Builders would make large wheels by using these rods as spokes sticking out from the center hub My favorite project was a rotating space station Short spokes radiated from all the holes in the center hub and connected w
266. riables accordingly However different machines have different requirements and homing is actually quite complicated 5 4 2 Homing Sequence Figure 5 1 shows four possible homing sequences along with the associated configuration parameters For a more detailed description of what each configuration parameter does see the following section 5 4 3 Configuration There are six pieces of information that determine exactly how the home sequence behaves They are defined in the ini and can be tweaked to obtain the result you are after 5 4 3 1 HOME_SEARCH_VEL HOME_SEARCH VEL is defined in each AXIS section The default value is zero A value of zero causes EMC to assume that there is no home switch The search and latch stages of homing are skipped EMC declares the current position to be HOME_OFFSET and does a rapid to HOME if HOME is not equal to HOME_OFFSET If HOME_SEARCH_VEL is non zero then EMC assumes that there is a home switch It begins by checking whether the home switch is already tripped If so it backs off the switch at HOME_SEARCH_VEL the direction of the back off is opposite the sign of HOME_SEARCH_VEL Then it searches for the home switch by moving in the direction specified by the sign of HOME_SEARCH_VEL at a speed determined by its absolute value When the home switch is detected the joint will stop as fast as possible but there will always be some overshoot The amount of overshoo
267. rminal Tabs Help mands These commands can be very powerful As you can see from the two lines above text commands can simplify many of the menu or click things you can do in the graphical en vironment The only limitation you ll find in the text environment is that you will have to type each command with great care for precision so that Linux s command interpreter will un derstand what you want it to do rayh rayu rayh rayu rayharayu rayh rayu mkdir p emc2 configs Figure 3 2 shows a terminal Whenever a terminal starts it will give you a command prompt This prompt will include information about where it is running within the file system and who it thinks you are In this picture the terminal thinks I am rayh on a computer named rayu and I am in my home directory 3 3 Starting a Custom Configuration You will be able to see and easily run your custom configurations if you place them where the Con figuration Selector can find them Any of the methods above will make a copy that the Configuration Selector will find Once a configuration has been edited into shape and tested on a machine it is possible to start that configuration using a command like emc emc2 configs stepper stepper_inch ini issued in a terminal in the users home directory It is also possible to make an icon on the desktop that starts the system The dialog shown as Figure 3 3 is what the Ubuntu Launcher Icon maker looks like Start it
268. rrent location of X becomes zero A G92 X2 will set an offset of 0 0000 and the displayed position will not change A G92 X5 0000 will set an offset of 3 0000 so that the current displayed position becomes 5 0000 CHAPTER 21 COORDINATE SYSTEM AND G92 OFFSETS 175 21 4 3 G92 Cautions Sometimes the values of a G92 offset get stuck in the VAR file When this happens reset or a startup will cause them to become active again The variables are named 5211 0 000000 5212 0 000000 5213 0 000000 5214 0 000000 5215 0 000000 5216 0 000000 where 5211 is the X axis offset and so on If you are seeing unexpected positions as the result of a commanded move or even unexpected numbers in the position displays when you start up look at these variables in the VAR file and see if they contain values If they do set them to zeros and the problems should go away With these tests we can see that reset returns g92 to the condition that it had when the interpreter started up The reader should note that we have established that no write of these values occurs during a normal run so if no g92 was set at the startup none will be read in during a reset It may be that this is the heart of the problem that some have experienced with differences between the old and the new interpreter It may well be but I leave it to others to test that the old interpreter and task programs immediately wrote values to the var file and then found those values during a reset
269. s Table 12 2 Parameters Used by the RS274NGC Interpreter Parameter Number s Meaning 5061 5066 Result of G38 2 Probe 5161 5166 G28 Home 5181 5186 G30 Home 5211 5216 G92 offset 5220 Coordinate System Number 5221 5226 Coordinate System 1 5241 5246 Coordinate System 2 5261 5266 Coordinate System 3 5281 5286 Coordinate System 4 5301 5306 Coordinate System 5 5321 5326 Coordinate System 6 5341 5346 Coordinate System 7 5361 5366 Coordinate System 8 5381 5386 Coordinate System 9 The format of a parameter file is shown in Table 12 3 The file consists of any number of header lines followed by one blank line followed by any number of lines of data The Interpreter skips over the header lines It is important that there be exactly one blank line with no spaces or tabs even before the data The header line shown in Table 12 3 describes the data columns so it is suggested but not required that that line always be included in the header The Interpreter reads only the first two columns of the table The third column Comment is not read by the Interpreter Each line of the file contains the index number of a parameter in the first column and the value to which that parameter should be set in the second column The value is represented as a double precision floating point number inside the Interpreter but a decimal point is not required in the file
270. s along the path just made by the tool The amount of offset required should be just enough that the tool tip will slide down through the bore 0 0 0 Y Ei Now the g87 canned cycle turns the spindle on and moves back up into the bore at the programmed feedrate This is the real cutting action of this canned cycle With the proper tool in a boring bar this cycle will produce a chamfer on the bottom side of the bore G87 can also be used to produce a larger diameter bore on the bottom side of the bore CHAPTER 22 CANNED CYCLES 185 When the tool has reached the K position it is returned to PA ei acne the bottom location the spindle is stopped and oriented and ee eee eats follows the earlier path back out of the bore to the initial position above 0 0 0 This canned cycle assumes spindle orientation which has not been implemented in the EMC to date The proper alignment of the tool tip to the oriented spindle is critical to the successful insertion of the tool through the hole to be backbored 22 10 G88 Cycle The G88 cycle is intended for boring This cycle uses a P value where P specifies the number of seconds to dwell Preliminary motion as described above Move the Z axis only at the current feed rate to the Z position Dwell for the given number of seconds Stop the spindle turning Stop the program so the operator can retract the spindle manually a F WwW N YF O Restart the spindle in the direction it
271. s critical to safe and effective machine operation Items are executed in the order shown below if they occur on the same line Eu Comment including message 2 set feed rate mode G93 G94 3 set feed rate F 4 set spindle speed S 5 select tool T 6 change tool M6 7 spindle on or off M3 M4 M5 8 coolant on or off M7 M8 M9 9 enable or disable overrides M48 M49 10 dwell G4 11 set active plane G17 G18 G19 N set length units G20 G21 ioe cutter radius compensation on or off G40 G41 G42 N cutter length compensation on or off G43 G49 al coordinate system selection G54 G55 G56 G57 G58 G59 G59 1 G59 2 G59 3 O set path control mode G61 G61 1 G64 Eh NX set distance mode G90 G91 a 00 set retract mode G98 G99 pi home G28 G30 or change coordinate system data G10 or set axis offsets G92 G92 1 G92 2 G94 20 perform motion GO to G3 G33 G80 to G89 as modified possibly by G53 21 stop MO M1 M2 M30 M60 157 Chapter 19 G Code Best Practices 19 1 Use an appropriate decimal precision Use at least 3 digits after the decimal when milling in millimeters and at least 4 digits after the decimal when milling in inches In particular arc tolerance checks are made to 001 and 0001 depending on the active units 19 2 Use consistent white space G code is most legible w
272. s set to 80 then the resulting spindle speed will be 400 RPM This slider has a minimum and maximum value defined in the ini file Ifthose are missing the slider is stuck at 100 The text box with the number is clickable Once clicked a popup window will appear allowing for a number to be entered 10 4 Keyboard Controls Almost all actions in TKEMC can be accomplished with the keyboard Many of the shortcuts are unavailable when in MDI mode The most frequently used keyboard shortcuts are shown in Table 10 1 Table 10 1 Most Common Keyboard Shortcuts Keystroke Action Taken Fl Toggle Emergency Stop F2 Turn machine on off 11 9 0 Set feed override from 0 to 100 X lt Activate first axis Y 1 Activate second axis Z 2 Activate third axis A 3 Activate fourth axis Home Send active axis Home Left Right Jog first axis Up Down Jog second axis Pg Up Pg Dn Jog third axis Jog fourth axis ESC Stop execution Chapter 11 Using The MINI Graphical Interface 11 1 Introduction o Stepper Freqmod Minimill X 0 0000 Y 0 0000 Z 0 0000 Feed Override 100 MESSAGES Figure 11 1 The Mini Graphical Interface Mini was designed to be a full screen graphical interface It was first written for the Sherline CNC but is available for anyone to use copy and distribute under the terms of the GPL copyright Rather than po
273. s something to watch Notice the following description of building a set of motion components in the HAL and how much like a wall of lego blocks it is The motion module exports a pin for each axis in cartesean space and another pin for each axis in joint space When it is loaded it automatically creates a jumper signal for each axis and automatically connects those signals from the joint pin to the cartesean pin So you automatically have trivkins as soon as you load the motion module trivkins trivial kinematics is the case where each motor moves a single axis at 90 degrees to the others The motion module is like a pair of legos in a line end to end Trivkins is just like a single block overlapping the two The in and out motion pins are plugged into each other by the block resting above But the parallel goes on If you need some other kinematics you then load a specific kins component This component knows the names of the pins that the motion module uses for each axis both joint and cartesean When the module loads it again automatically creates signals and connects its own pins to the motion module s pins which will disconnect the jumpers It could also know the thread names used by the motion module and could automatically add its own functions to those threads Trivkins is removed so that the motion blocks can be spread apart and by using other blocks a different bridge is built between input and output pins In Leg
274. separated on single lines Each end of line or newline character creates a new element 5 2 1 Comments A comment line is started with a or a mark When the ini reader sees either of these marks at the start a line the rest of the line is ignored by the software Comments can be used to describe what some INI element will do This is my little mill configuration file I set it up on January 12 2006 Comments can also be used to select between several values of a single variable DISPLAY tkemc DISPLAY axis DISPLAY mini DISPLAY keystick In this list the DISPLAY variable will be set to axis because all of the others are commented out If someone carelessly edits a list like this and leaves two of the lines uncommented the first one encountered will be used 5 2 2 Sections Sections in an INI file work like file folders in a drawer They separate variables based on what part of the EMC they refer to A section line looks like THIS_SECTION The name of the section is enclosed in brackets Common INI files have several sections including e EMC general information 5 3 1 e DISPLAY selects and sets up some display characteristics 5 3 2 e TASK sets up the task planner 5 3 4 e RS274NGC location of interpreter specific file e EMCMOT motion module and default characteristics 5 3 3 e HAL hardware configuration files and commands 5 3 5 e TRAJ information for the motion planner 5 3
275. set Output parameters cannot be adjusted by the user they are equivalent to test points that allow internal signals to be monitored Pin Hardware components have terminals which are used to interconnect them The HAL equivalent is a pin or HAL pin HAL pin is used when needed to avoid confusion All HAL pins are named and the pin names are used when interconnecting them HAL pins are software entities that exist only inside the computer Physical_Pin Many I O devices have real physical pins or terminals that connect to external hardware for example the pins of a parallel port connector To avoid confusion these are referred to as physical pins These are the things that stick out into the real world Signal In a physical machine the terminals of real hardware components are interconnected by wires The HAL equivalent of a wire is a signal or HAL signal HAL signals connect HAL pins together as required by the machine builder HAL signals can be disconnected and reconnected at will even while the machine is running Type When using real hardware you would not connect a 24 volt relay output to the 10V analog input of a servo amp HAL pins have the same restrictions which are based upon their type Both pins and signals have types and signals can only be connected to pins of the same type Currently there are 4 types as follows BIT a single TRUE FALSE or ON OFF value FLOAT a 32 bit floating point value
276. slider s open slot on the side you want it to move toward or by clicking on the Default or Rapid buttons This setting only affects the jog move while in manual mode Once a jog move is initiated jog speed has no effect on the jog As an example of this say you set jog mode to incremental and the increment to 1 inch Once you press the Jog button it will travel that inch at the rate at which it started 11 4 2 AUTO When the Auto button is pressed or lt F4 gt on the keyboard the EMC is changed into that mode a set of the traditional auto operation buttons is displayed and a small text window opens to show a part program During run the active line will be displayed as white lettering on a red background In the auto mode many of the keyboard keys are bound to controls For example the numbers above the querty keys are bound to feedrate override The O sets 100 9 sets 90 and such Other keys work much the same as they do with the tkemc graphical interface Opan Run Pansa Resume Stap Varify ide This is a test plot nc program to bs ran on back plot n101 Anthor Ray Henry 10 Feb 2000 n102 0 53 x0 y0 20 130 n103 x1 yl start xy circio n104 17 02 x2 y2 regrt 0 5 n105 xl y1 11 1 sqrt 0 51 n106 0 z 1 add xy lettering n107 y1 75 n108 z0 Figure 11 4 Auto Mode Auto mode does not normally display the active or modal codes If the operator wishes to check these use menu Info gt Active_G Cod
277. slow runs every millisecond and is capable of running floating point functions We will use it for siggen 0 update and freqgen update_freq The second thread is fast which runs every 50 microseconds and does not support floating point We will use it for freqgen make_pulses To connect the functions to the proper thread we use the addf command We specify the function first followed by the thread halcmd addf siggen 0 update slow halcmd addf freqgen update_freq slow halcmd addf freqgen make_pulses fast After we give these commands we can run the show thread command again to see what happened halcmd show thread Realtime Threads Period FP Name Time Max Time 1005720 YES slow 07 0 1 siggen 0 update 2 freqgen update freg 50286 NO fast 0 0 1 freqgen make pulses Now each thread is followed by the names of the functions in the order in which the functions will run CHAPTER 7 HAL TUTORIAL 64 7 5 4 Setting parameters We are almost ready to start our HAL system However we still need to adjust a few parameters By default the siggen component generates signals that swing from 1 to 1 For our example that is fine we want the table speed to vary from 1 to 1 inches per second However the scaling of the step pulse generator isn t quite right By default it generates an output frequency of 1 step per second with an input of 1 000 It is unlikely that one step per second will give us one inch per second
278. t e FUNCT ppmc lt port gt write Writes all outputs digital outputs stepgens PWMs on one port Part III Using EMC2 Chapter 9 Using the AXIS Graphical Interface 9 1 Introduction AXIS is a graphical front end for emc2 which features a live preview and backplot It is written in Python and uses Tk and OpenGL to display its user interface Figure 9 1 AXIS Window Eile Machine View Help OGIR gira Manual Control F3 MDI F5 Axis Or OY el Continuous _Home Touch Off Override Limits Spindle stop Q E El Brake Coolant P Mist Flood Feed Override 100 Jog Speed 72 infmin AXIS 1 4a0 splash g code A Not intended for actual milling e 620 1 1 1 SH 2 1 CUT 3 0002 SCALE F999 GOO 21 GOO X 1688 00 3 Y 842 00 3 ON No tool Position Relative Actual 91 CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 92 9 2 Getting Started To select AXIS as the front end for emc2 edit the ini file In the section DISPLAY change the DISPLAY line to read DISPLAY axis Then start emc2 and select that ini file The sample configuration sim axis ini is already config ured to use AXIS as its front end When you start AXIS a window like the one in Figure 9 1 is shown 9 2 1 Atypical session with AXIS p Start emc and select a configuration file Clear the ESTOP condition and turn the machine on
279. t Program Display Area By left clicking a line of the program the line will be highlighted in both the graphical and text displays When the program is running the line currently being executed is highlighted in red If no line has been selected by the user the text display will automatically scroll to show the current line CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 95 Figure 9 2 Current and Selected Lines File Machine View Help 010 10 211 gt Z NIX LY BP b Manual Control F3 MDI F5 Axis e amp E al x Override Limits Spindle vol eB SA Coolant I r Feed Override 30 at Jog Speed 72 in min saa 24 GOL X 328 00 3 485 00 3 25 GOL X 2262 00 3 2816 00 3 27 GOL X 2304 00 3 Y 552 00 3 GOL X 2335 00 43 Y 176 00 3 601 X 2494 00 3 119 00 3 601 X 2474 00 3 Y 0 00 43 601 X 1311 00 3 Y 0 00 3 ON No tool Position Relative Actual 9 3 4 Manual Control While the machine is turned on but not running a program the items in the Manual Control tab can be used to move the machining center or turn different parts of it on and off When the machine is not turned on or when a program is running the manual controls are un available Many of the items described below are not useful on all machines When AXIS detects that a partic ular pin is not connected in HAL the corresponding item in the Manual Control tab
280. t board gt dac lt channel gt offset Sets the DAC offset e FLOAT motenc lt board gt dac lt channel gt gain Sets the DAC gain scaling e FLOAT motenc lt board gt adc lt channel gt offset Sets the ADC offset e FLOAT motenc lt board gt adc lt channel gt gain Sets the ADC gain scaling e BIT motenc lt board gt out lt channel gt invert Inverts a digital output see canonical digital output e u32 motenc lt board gt watchdog control Configures the watchdog The value may be a bitwise OR of the following values Bit Value Meaning 0 1 Timeout is 16ms if set 8ms if unset 2 4 Watchdog is enabled 4 16 Watchdog is automatically reset by DAC writes the HAL dac write function Typically the useful values are O watchdog disabled or 20 8ms watchdog enabled cleared by dac write e u32 motenc lt board gt led view Maps some of the I O to onboard LEDs 8 6 4 Functions e FUNCT motenc lt board gt encoder read Reads all encoder counters e FUNCT motenc lt board gt adc read Reads the analog to digital converters e FUNCT motenc lt board gt digital in read Reads digital inputs e FUNCT motenc lt board gt dac write Writes the voltages to the DACs e FUNCT motenc lt board gt digital out write Writes digital outputs e FUNCT motenc lt board gt misc update Updates misc stuf
281. t depends on the speed If it is too high the joint might overshoot enough to hit a limit switch or crash into the end of travel On the other hand if HOME SEARCH _VEL is too low homing can take a long time 5 4 3 2 HOME_LATCH VEL HOME_LATCH_VEL is also defined in the ini file for each AXIS It specifies the speed and direction that EMC uses when it makes its final accurate determination of the home switch and index pulse location It will usually be slower than the search velocity to maximise accuracy If HOME_SEARCH_VEL and HOME_LATCH_VEL have the same sign then the latch phase is done while moving in the same direction as the search phase In that case EMC first backs off the switch before moving towards it again at the latch velocity If HOME_SEARCH_VEL and HOME_LATCH_VEL have opposite signs the latch phase is done while moving in the opposite direction from the search phase That means EMC will latch the first pulse after it moves off the switch If HOME_SEARCH_VEL is zero the latch phase is skipped and this parameter is ignored If HOME_SEARCH_VEL is non zero and this parameter is zero it is an error and the homing operation will fail The default value is zero CHAPTER 5 INI CONFIGURATION SEARCH_VEL POSITIVE HOME_OFFSET 3 000 HOME SWITCH RELEASES LATCH_VEL NEGATIVE HOME 1 000 HOME SWITCH TRIPS USE_INDEX FALSE ld IE OVERSHOOT SEARCH FOR HOME SWITCH SEARCH_VEL l FINAL DETECTION OF SWITCH LATCH_V
282. t entry a comment is optional It makes reading easier if the entries are arranged in columns as shown in the table but the only format requirement is that there be at least one space or tab after each of the first three entries on a line and a space tab or newline at the end of the fourth entry The meanings of the columns and the type of data to be put in each are as follows The Pocket column contains an unsigned integer which represents the pocket number slot num ber of the tool carousel slot in which the tool is placed The entries in this column must all be different The FMS column contains an unsigned integer which represents a code number for the tool The user may use any code for any tool as long as the codes are unsigned integers The TLO column contains a real number which represents the tool length offset This number will be used if tool length offsets are being used and this pocket is selected This is normally a positive real number but it may be zero or any other number if it is never to be used The Diameter column contains a real number This number is used only if tool radius compensa tion is turned on using this pocket If the programmed path during compensation is the edge of the CHAPTER 12 RETURN MACHINING CENTER OVERVIEW 128 material being cut this should be a positive real number representing the measured diameter of the tool If the programmed path during compensation is the path of a
283. t it stays tangent to the auxiliary arc throughout the move This is shown in Figure 10 Regardless of whether the first move is a straight line or an arc the Z axis may also move at the same time It will move linearly as it does when cutter radius compensation is not being used Rotary axis motions A B and C axes are allowed with cutter radius compensation but using them would be very unusual After the entry moves of cutter radius compensation the interpreter keeps the tool tangent to the programmed path on the appropriate side If a convex corner is on the path an arc is inserted to go around the corner The radius of the arc is half the diameter given in the tool table When cutter radius compensation is turned off no special exit move takes place The next move is what it would have been if cutter radius compensation had never been turned on and the previous move had placed the tool at its current position Programming Entry Moves In general an alignment move and two entry moves are needed to begin compensation correctly However where the programmed contour is a material edge contour and there is a convex corner on the contour only one entry move plus possibly a pre entry move is needed The general method which will work in all situations is described first We assume here that the programmer knows what the contour is already and has the job of adding entry moves General Method The general method includes programming
284. t to 80 then the resulting spindle speed will be 6400 This item only appears when the HAL pin motion spindle speed out is connected 9 3 8 Jog Speed By moving this slider the speed of jogs can be modified For instance if the slider is set to 1 in min then a 01 inch jog will complete in about 6 seconds or 1 100 of a minute Near the left side slow jogs the values are spaced closely together while near the right side fast jogs they are spaced much further apart allowing a wide range of jog speeds with fine control when it is most important On machines with a rotary axis a second jog speed slider is shown This slider sets the jog rate for the rotary axes A B and C 9 4 Keyboard Controls Almost all actions in AXIS can be accomplished with the keyboard A full list of keyboard shortcuts can be found in the AXIS Quick Reference which can be displayed by choosing HELP gt QUICK REFERENCE Many of the shortcuts are unavailable when in Code Entry mode The most frequently used keyboard shortcuts are shown in Table 10 1 Table 9 1 Most Common Keyboard Shortcuts Keystroke Action Taken Fl Toggle Emergency Stop F2 Turn machine on off 1 9 0 Set feed override from 0 to 100 X Activate first axis Y 1 Activate second axis Z 2 Activate third axis A 3 Activate fourth axis I Select jog increment C Continuous jog Control Home Perform homing sequenc
285. t with the Z axis when X and Y are zero The spindle can be stopped in a fixed orientation or stopped without specifying orientation 12 1 4 Coolant A machining center has components to provide mist coolant and or flood coolant 12 1 5 Pallet Shuttle A machining center has a pallet shuttle system The system has two movable pallets on which workpieces can be fixtured Only one pallet at a time is in position for machining 12 1 6 Tool Carousel A machining center has a tool carousel with slots for tools fixed in tool holders 12 1 7 Tool Changer A machining center has a mechanism for changing tools fixed in tool holders between the spindle and the tool carousel 12 1 8 Message Display A machining center has a device that can display messages 12 1 9 Feed and Speed Override Switches A machining center has separate feed and speed override switches which let the operator specify that the actual feed rate or spindle speed used in machining should be some percentage of the programmed rate See Section 12 3 1 12 1 10 Block Delete Switch A machining center has a block delete switch See Section 12 3 2 12 1 11 Optional Program Stop Switch A machining center has an optional program stop switch See Section 12 3 3 CHAPTER 12 RETURN MACHINING CENTER OVERVIEW 124 12 2 Control and Data Components 12 2 1 Linear Axes The X Y and Z axes form a standard right handed coordinate system of orthogonal linear axes Positions
286. t would save the g92 values when you shut down the EMC and they will be recalled when you start up again Chapter 22 Canned Cycles Canned Cycles G81 through G89 have been implemented for milling This section describes how each cycle has been implemented In addition G80 and G98 G99 are considered here because their primary use is related to canned cycles All canned cycles are performed with respect to the XY plane With the current 3 axis interpreter no A B C axis motion is allowed during canned cycles inverse time feed rate is not allowed cutter radius compensation is not allowed Each of the canned cycles defines a new machine motion mode As a motion mode they will stay in effect until replaced by another motion G word or by G80 as described below All canned cycles use X Y R and Z values in the NC code These values are used to determine X Y R and Z positions The R usually meaning retract position is along the Z axis Some canned cycles use additional arguments that are listed with the specific cycle In absolute distance mode the X Y R and Z values are absolute positions in the current coordinate system In incremental distance mode X Y and R values are treated as increments to the current position and Z as an increment from the Z axis position before the move involving Z takes place A repeat feature has been implemented The L word represents the number of repeats If the repeat feature is used it is normally used i
287. tch o ck ee a wee a A ae ee 123 12 1 11 Optional Program Step Switeh o ss s ww sa sos ea s are a a a a 123 12 2 Control and Data Components s EE asma wrk e es 124 12 2 1 Lincar ARES eaa eaa a a a A E a ee ee aw 124 Aa BOTAR SES 00 a a OE a a a we ee Ge ee dae Oe de 124 122 Controlled POL 0 ls ac es RE a a ew a eS 124 12 2 4 Coordinate Linear Motion 124 A A 124 LED OO O ac A E e PEE Ra A a ee a eS 125 LAZI Dwel ceges ee a a A e a a ee 125 a WN ee adi ans EO Ge pees BO GS EE BS ee OO SE ee i ee 125 1429 Current Poste ca nck pe A EE a ee Pee des Bak ew 125 Nee WO ii PRAIA aca GS kB eae Bi we Ha E AP Ge ae GB else a om 125 PL TRC APOE o a Se ke Pe Ow AOS ws Go Ge ee a ee 126 TALLA TOILECASDES s co a Re AAA ae ee Pew de a al ar 8 126 AS Palet SIS ee oe aie A wg a A we Few a Sa aw A we ed we woe 126 12 2 14 Feed and Speed Override Switches s soas ee 126 122 15 Path Control Mode s 6 284486 eee hd ea ee Paw dae aa ae 8 126 12 3 Interpreter Interaction with Switches e 126 12 3 1 Feed and Speed Override Switches ee 126 2 3 2 Block Delete Swatch cht ace eee ARR Ree Dw ee a 126 12 3 3 Optional Program Stop Switch ee ee ee ee ee 127 UA Tool PS ei ee a a a a a Ve ea we 127 120 Porn a ES AS eee Ca eee hah eek ee 128 CONTENTS 13 Language Overview 13 1 Pomatol a line ociosos ek ee a ee a 13 3 3 Expressions and Binary Operations
288. tches 6 3 2 Internal Components stepgen Software step pulse generator with position loop See section freqgen Software step pulse generator See section encoder Software based encoder counter See section pid Proportional Integral Derivative control loops See section siggen A sine cosine triangle square wave generator for testing See section supply a simple source for testing blocks assorted useful components mux demux or and integ ddt limit wcomp etc CHAPTER 6 INTRODUCTION 47 6 3 3 Hardware Drivers hal_ax5214h A driver for the Axiom Measurement amp Control AX5241H digital I O board hal m5i20 Mesa Electronics 5i20 board hal_motenc Vital Systems MOTENC 100 board hal_parport PC parallel port See section 8 1 hal_ppmc Pico Systems family of controllers PPMC USC and UPC hal_stg Servo To Go card version 1 2 hal vti Vigilant Technologies PCI ENCDAC 4 controller 6 3 4 Tools and Utilities halemd Command line tool for configuration and tuning See section halgui GUI tool for configuration and tuning not implemented yet halmeter A handy multimeter for HAL signals See section halscope A full featured digital storage oscilloscope for HAL signals See section Each of these building blocks is described in detail in later chapters 6 4 Tinkertoys Erector Sets Legos and the HAL A first introduction to HAL concepts can be mind boggling Building anything with blocks can be a challe
289. ten by the first program and use it as the parameter file for the second program CHAPTER 14 G CODES 149 14 20 G93 G94 Set Feed Rate Mode Two feed rate modes are recognized units per minute and inverse time Program G94 to start the units per minute mode Program G93 to start the inverse time mode In units per minute feed rate mode an F word is interpreted to mean the controlled point should move at a certain number of inches per minute millimeters per minute or degrees per minute depending upon what length units are being used and which axis or axes are moving In inverse time feed rate mode an F word means the move should be completed in one divided by the F number minutes For example if the F number is 2 0 the move should be completed in half a minute When the inverse time feed rate mode is active an F word must appear on every line which has a Gl G2 or G3 motion and an F word on a line that does not have Gl G2 or G3 is ignored Being in inverse time feed rate mode does not affect GO rapid traverse motions It is an error if e inverse time feed rate mode is active and a line with G1 G2 or G3 explicitly or implicitly does not have an F word 14 21 G98 G99 Set Canned Cycle Return Level When the spindle retracts during canned cycles there is a choice of how far it retracts 1 retract perpendicular to the selected plane to the position indicated by the R word or 2 retract perpen dicular to the selected
290. terior of part cut Some other things to note are that the program starts with a G40 to turn off any compensation that was in effect This saves a lot of hassle when the program stops due to a concavity error but leaves the compensation turned on Also note in line 15 that G17 is used to select the XY plane for circular interpolation I have used the radius form of arc center specification rather than the I J form EMC is very picky about the radius it computes from I J coordinates and they must match at the beginning and end of the move to within 104 11 internal units so you will have lots of problems with arbitrary arcs Usually if you do an arc of 90 degrees centered at 1 0 1 0 with a radius of 1 everything will go fine but if it has a radius that can not be expressed exactly in just a few significant digits or the arc is a strange number of degrees then there will be trouble with EMC The R word clears up all that mess and is a lot easier to work with anyway If the arc is more than 180 degrees R should be negative 20 5 Tool Compensation Sources This unit borrows heavily from the published works of Tom Kramer and Fred Proctor at NIST and the cutter compensation web page of Jon Elson CHAPTER 20 TOOL FILE AND COMPENSATION Papers by Tom Kramer and Fred Proctor http www isd mel nist gov personnel kramer publications html http www isd mel nist gov personnel kramer pubs RS274NGC_22 pdf http www isd mel nist gov person
291. th the mouse or holding down a key on the keyboard In auto mode a similar button or key press might be used to load or start the running of a whole program of G code that is stored in a file In the MDI mode the operator might type in a block of code and tell the machine to execute it by pressing the lt return gt or lt enter gt key on the keyboard Some motion control commands are available and will cause the same changes in motion in all CHAPTER 1 THE ENHANCED MACHINE CONTROL 10 dim Filis mur Fuel Lrips H Ti MESE CEE a SPANIE Fa iers MAITE Fl del FF ARAKF OOH lool Foston Actual Kalakva Jonk fael 2 on Work OTe ta STOR 000080 200001000 1 8273 3 9150 3 6875 10 5600 increment So Mohan heed Overmle Logging comemos iiomo 4 100 gt BA caos not toying u d GT GIS HA Gi G H4 ad GE HA GEJ M M MH A HE E Prora EA EA s Stats Open Tan Pause Resume step verity PAUSCO E omy MEN Aes E hea E E TL AA E A OA E TE reper Pl A Figure 1 6 The XEMC Graphical Interface modes These include ABORT ESTOP and FEEDRATE OVERRIDE Commands like these should be self explanatory 1 6 2 Information Display While an EMC2 is running each of the modules keeps up a conversation with the others and with the graphical display It is up to the display to select from that stream of information what the operator needs to see and to arrange it on the screen
292. that putting more than one comment on a line will be very rare 13 7 Item order The three types of item whose order may vary on a line as given at the beginning of this section are word parameter setting and comment Imagine that these three types of item are divided into three groups by type The first group the words may be reordered in any way without changing the meaning of the line If the second group the parameter settings is reordered there will be no change in the meaning of the line unless the same parameter is set more than once In this case only the last setting of the parameter will take effect For example after the line 3 15 3 6 has been interpreted the value of parameter 3 will be 6 If the order is reversed to 3 6 3 15 and the line is interpreted the value of parameter 3 will be 15 If the third group the comments contains more than one comment and is reordered only the last comment will be used If each group is kept in order or reordered without changing the meaning of the line then the three groups may be interleaved in any way without changing the meaning of the line For example the line g40 g1 3 15 foo 4 7 0 has five items and means exactly the same thing in any of the 120 possible orders such as 4 7 0 gl 3 15 g40 foo for the five items 13 8 Commands and Machine Modes In RS274 NGC many commands cause a machining center to change from on
293. the Mist and Flood coolants to be turned on and off Depending on your machine configuration not all the items in this group may appear CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 97 9 3 5 Code Entry Code Entry also called MDI allows G code programs can be entered manually one line at a time When the machine is not turned on or when a program is running the code entry controls are unavailable Figure 9 4 The Code Entry tab Manual Control F3 Code Entry FS History MOI Command AAA Active G Codes G80 G19 640 G20 G90 594 654 649 399 661 1 M4 M3 H4S FO 50 9 3 5 1 History This shows MDI commands that have been typed earlier in this session 9 3 5 2 MDI Command This allows you to enter a g code command to be executed Execute the command by pressing Enter or by clicking Go 9 3 5 3 Active G Codes This shows the modal codes that are active in the interpreter For instance G54 indicates that the G54 offset is applied to all coordinates that are entered 9 3 6 Feed Override By moving this slider the programmed feed rate can be modified For instance ifa program requests F60 and the slider is set to 120 then the resulting feed rate will be 72 CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 98 9 3 7 Spindle Speed Override By moving this slider the programmed spindle feed rate can be modified For instance if a program requests F8000 and the slider is se
294. the latched position as it stops Therefore there will always be a small move at this time unless HOME_SEARCH_VEL is zero and the entire search latch stage was skipped This final move will be made at the joint s maximum velocity Since the axis is now homed there should be no risk of crashing the machine and a rapid move is the quickest way to finish the homing sequence 5 4 3 7 HOME_IS_ SHARED HOME_IS_SHARED is a value setable from the ini in the AXIS_ section If there is not a separate home switch input for this axis but a number of momentary switches wired to the same pin set this value to 1 to prevent homing from starting if one of the shared switches is already closed Set this value to O to permit homing even if the switch is already closed 5 4 3 8 HOME_SEQUENCE HOME_SEQUENCE is a value setable from the ini in the AXIS section This value is used to perform a multi axis homing sequence HOME ALL and enforce homing order e g Z may not be homed if X is not yet homed An axis may be homed after all axes with a lower HOME_SEQUENCE have already been homed and are at the HOME_OFFSET If two axes have the same HOME_SEQUENCE they may be homed at the same time If HOME_SEQUENCE is 1 or not 8The distinction between home and home_offset is not as clear as I would like I intend to make a small drawing and example to help clarify it CHAPTER 5 INI CONFIGURATION specified then this joint will not be homed by the
295. tify you as the publisher of these copies The front cover must present the full title with all words of the title equally prominent and visible You may add other material on the covers in addition Copying with changes limited to the covers as long as they preserve the title of the Document and satisfy these conditions can be treated as verbatim copying in other respects If the required texts for either cover are too voluminous to fit legibly you should put the first ones listed as many as fit reasonably on the actual cover and continue the rest onto adjacent pages If you publish or distribute Opaque copies of the Document numbering more than 100 you must either include a machine readable Transparent copy along with each Opaque copy or state in or with each Opaque copy a publicly accessible computer network location containing a complete Transparent copy of the Document free APPENDIX B LEGAL SECTION 197 of added material which the general network using public has access to download anonymously at no charge using public standard network protocols Ifyou use the latter option you must take reasonably prudent steps when you begin distribution of Opaque copies in quantity to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy directly or through your agents or retailers of that edition to the public It is requested but not requi
296. tions as fully interleaved CHAPTER 8 HARDWARE DRIVERS 83 8 5 5 Connector pinout The Hostmot 4 FPGA configuration has the following pinout There are three 50 pin ribbon cable connectors on the card P2 P3 and P4 There are also 8 status LEDs 8 5 5 1 Connecor P2 m5i20 card connector P2 Function HAL pin 1 enc 01 A input 3 enc 01 B input 5 enc 00 A input 7 enc 00 B input 9 enc 01 index input 11 enc 00 index input 13 dac 01 output 15 dac 00 output 17 DIR output for dac 01 19 DIR output for dac 00 21 dac 01 enable output 23 dac 00 enable output 25 enc 03 B input 27 enc 03 A input 29 enc 02 B input 31 enc 02 A input 33 enc 03 index input 35 enc 02 index input 37 dac 03 output 39 dac 02 output 41 DIR output for dac 03 43 DIR output for dac 02 45 dac 03 enable output 47 dac 02 enable output 49 Power 5 V or 3 3V all even pins Ground 8 5 5 2 Connector P3 Encoder counters 4 7 work simultaneously with in 00 to in 11 If you are using in 00 to in 11 as general purpose IO then reading enc lt 4 7 gt will produce some random junk number CHAPTER 8 HARDWARE DRIVERS 84 m5i20 card connector P3 Function HAL pin Secondary Function HAL pin 1 in 00 enc 04 A input 3 in 01 enc 04 B input 5 in 02 enc 04 index input 7 in 03 enc 05 A input 9 in
297. to distinguish since all four are on top of each other To fix this we use the Vertical controls in the box to the right of the screen These controls act on the currently selected channel When adjusting the gain notice that it covers a huge range unlike a real scope this one can display signals ranging from very tiny pico units to very large Tera units The position control moves the displayed trace up and down over the height of the screen only For larger adjustments the offset button should be used see the halscope reference in section for details 7 6 5 Triggering Using the Force button is a rather unsatisfying way to trigger the scope To set up real triggering click on the Source button at the bottom right It will pop up the Trigger Source dialog which is simply a list of all the probes that are currently connected Figure 7 8 Select a probe to use for triggering by clicking on it For this example we will use channel 3 the triangle wave XA Trigger Source x Select a channel to use for triggering Chan Source 2 Y_vel 3 siqgen 1 triangle 4 siggen 1 square 5 6 ae 7 a 8 zone 3 10 11 12 Cancel Figure 7 8 Trigger Source Dialog After setting the trigger source you can adjust the trigger level and trigger position using the sliders in the Trigger box along the right edge The level can be adjusted from the top to the b
298. to these four files there is a standard startup file Back in the early days of the EMC it was common to have to start up several different tasks in different terminal windows in order to get the EMC to run a machine Each of these tasks had to be supplied a bunch of information in the form of arguments in order to be certain that the task started the way that we expected it to All of this was tedious and has been replaced by one script It is named simply emc This executable script file controls the startup of all of the modules needed to run a standard version of the EMC2 When run it lets the user choose a certain configuration Chapter 2 Installing the EMC2 software 2 1 Introduction One of the problems users often complained about EMC was installing the software itself They were forced to get sources and compile themselves and try to set up a RT patched Linux etc The developers of EMC2 chose to go with a standard distribution called Ubuntu Ubuntu has been chosen because it fits perfectly into the Open Source views of EMC2 Ubuntu will always be free of charge and there is no extra fee for the enterprise edition we make our very best work available to everyone on the same Free terms Ubuntu comes with full professional support on commercial terms from hundreds of compa nies around the world if you need those services Each new version of Ubuntu receives free security updates for 18 months after release some versions
299. tool whose diameter is nominal this should be a small number positive negative or zero representing the difference between the measured diameter of the tool and the nominal diameter If cutter radius compensation is not used with a tool it does not matter what number is in this column The Comment column may optionally be used to describe the tool Any type of description is OK This column is for the benefit of human readers only The units used for the length and diameter of the tool may be in either millimeters or inches but if the data is used by an NC program the user must be sure the units used for a tool in the file are the same as the units in effect when NC code that uses the tool data is interpreted The table shows a mixture of types of units The lines do not have to be in any particular order Switching the order of lines has no effect unless the same slot number is used on two or more lines which should not normally be done in which case the data for only the last such line will be used 12 5 Parameters In the RS274 NGC language view a machining center maintains an array of 5400 numerical pa rameters Many of them have specific uses The parameter array persists over time even if the machining center is powered down EMC2 uses a parameter file to ensure persistence and gives the Interpreter the responsibility for maintaining the file The Interpreter reads the file when it starts up and writes the file when it exit
300. tput see canonical digital output u32 m5i20 lt board gt watchdog control Configures the watchdog The value may be a bitwise OR of the following values Bit Value Meaning 0 1 Watchdog is enabled 1 2 Watchdog is automatically reset by DAC writes the HAL dac write function Typically the useful values are O watchdog disabled or 3 watchdog enabled cleared by dac write e u32 m5i20 lt board gt led view Maps some of the I O to onboard LEDs See table below 8 5 4 Functions e FUNCT m5i20 lt board gt encoder read Reads all encoder counters e FUNCT m5i20 lt board gt digital in read Reads digital inputs e FUNCT m5i20 lt board gt dac write Writes the voltages PWM duty cycles to the DACs e FUNCT m5i20 lt board gt digital out write Writes digital outputs e FUNCT m5i20 lt board gt misc update Writes watchdog timer configuration to hardware Resets watchdog timer Updates E stop pin more info needed Updates onboard LEDs 10With normal 10 bit PWM 50 duty cycle would be 512 cycles on and 512 cycles off ca 30 kHz with 33 MHz reference counter With fully interleaved PWM this would be 1 cycle on 1 cycle off for 1024 cycles 16 66 MHz if the PWM reference counter runs at 33 MHz much easier to filter The 5120 configuration interlace is somewhat between non and fully interlaced to make it easy to filter but not have as many transis
301. ture for the specific axis The values inside are triplets of nominal forward and reverse positions which correspond to the nominal position where it should be forward where the axis is while travelling forward and reverse where the axis is while travelling back One set of triplets per line Currently the limit inside EMC2 is for 256 triplets axis COMP_FILE_TYPE 1 Specifying a non zero value changes the expected format of the COMP_FILE While type O the expected values are triplets for nominal forward amp reverse With COMP_FILE_TYPE non zero the expected values in the COMP_FILE are nominal forward_trim and reverse_trim These correspond to the nominal nominal forward and nominal reverse defined above INPUT_SCALE 4000 This variable has slightly different meaning for stepper and for servo systems For steppers the only number it is the number of pulses required to move the axis one UNIT For servos this value is the scale factors for the axis input from the raw feedback device e g an incremental encoder The units on the scale value are in raw units e g counts per user units e g inch The value for scale can be obtained by doing a unit analysis i e units are sensor units desired input SI units For example on a 2000 counts per rev encoder and 10 revs inch gearing and desired units of mm we have t inch scaleunits 2000 a 10 e 1 25 4 rev inch mm counts A 787 lt a and
302. ty DAC units etc To do this follow this procedure 1 Build a calibration table for the output driving the DACs with a desired voltage and measuring the result See table 5 3 7 2 for an example of voltage measurements 2 Do a least squares linear fit to get coefficients a b such that meas ax raw b 3 Note that we want raw output such that our measured result is identical to the commanded output This means a cmd a x raw b b raw cmd b a 4 As a result the a and b coefficients from the linear fit can be used as the scale and offset for the controller directly MAX_OUTPUT 10 The maximum value for the output of the PID compensation that is written to the motor amplifier in volts The computed output value is clamped to this limit The limit is applied before scaling to raw output units MIN_OUTPUT 10 The minimum value for the output of the PID compensation that is written to the motor amplifier in volts The computed output value is clamped to this limit The limit is applied before scaling to raw output units 5 3 7 3 Stepper related items The following items are used by core_stepper hal to set limits on the step waveforms that will be generated They typically include a headroom of 5 to 10 compared to the MAX_VELOCITY and MAX_ACCEL items in the same AXIS CHAPTER 5 INI CONFIGURATION 36 Output Voltage Measurements Raw Measured 10 9 93 9 8 83 0 0 03
303. u want to edit this manually just change the number and leave the other tags alone MACHINE My Controller This is the name of the controller which is printed out at the top of most graphical interfaces You can put whatever you want here as long as you make it a single line long RS274NGC_STARTUP_CODE G21 G90 A string of NC codes that the interpreter is initialized with These are the codes that an interpreter will be reset to 5 3 2 DISPLAY Section DISPLAY tkemc The name of the user interface to use Valid options may include e axis e keystick e mini e tkemc e xemc 5 3 3 EMCMOT Section BASE_PERIOD 50000 Base task period in nanoseconds this is the fastest thread in the machine It s units are nanoseconds This is a fairly conservative value but if you are installing on a very old slow processor you may have to make this a larger number or the machine may lock up or reboot You might want to make this value smaller if you have a fast computer because this value sets the maximum number of stepper pulses you can get from your machine It has little CHAPTER 5 INI CONFIGURATION 31 effect on servo systems so leave it large In the absence of long setup or hold times the absolute maximum step rate for a step direction motor is one step per tw BASE_PERIOD so 9 steps 10 mazx_step_rate second 2 x base_period Thus the BASE_PERIOD shown above gives an absolute maximum step rate of 10000 steps per se
304. ue of an internal counter that counts the step pulses as they are generated Assuming no missed steps this counter indicates the position of the motor The main function for the step pulse generator is freqgen make_pulses Every time make_pulses runs it decides if it is time to take a step and if so sets the outputs accordingly For smooth step pulses it should run as frequently as possible Because it needs to run so fast make_pulses is highly optimized and performs only a few calculations Unlike the others it does not need floating point math The last function freqgen update_fregq is responsible for doing scaling and some other calculations that need to be performed only when the frequency command changes What this means for our example is that we want to run siggen 0 update at a moderate rate to calculate the sine and cosine values Immediately after we run siggen 0 update we want to run freqgen update_freq to load the new values into the step pulse generator Finally we need to run freqgen make_pulses as fast as possible for smooth pulses Because we don t use position feedback we don t need to run freqgen capture_position at all We run functions by adding them to threads Each thread runs at a specific rate Let s see what threads we have available halcmd show thread Realtime Threads Period FP Name 1005720 YES slow 0 O 50286 NO fast 70 0 The two threads were created when we loaded threads The first one
305. unction X and not finding it HAL can follow the normal DLL model as well Although most components will simply export pins functions and parameters and then wait for the integrator or a saved file to interconnect them we can write modules that attempt to make connections when they are installed One specific place where this would work well is kinematics as illustrated in the Lego section 6 4 4 CHAPTER 6 INTRODUCTION 51 Chapter 7 HAL Tutorial 7 1 Before we start Configuration moves from theory to device HAL device that is For those who have had just a bit of computer programming this section is the Hello World of the HAL As noted above halemd can be used to create a working system It is a command line or text file tool for configuration and tuning The following examples illustrate its setup and operation 7 1 1 Notation Command line examples are presented in bold typewriter font Responses from the computer will be in typewriter font Text inside square brackets like this is optional Text inside angle brackets lt like this gt represents a field that can take on different values and the adjacent paragraph will explain the appropriate values Text items separated by a vertical bar means that one or the other but not both should be present All command line examples assume that you are in the emc2 directory and paths will be shown accordingly when needed 7 1 2 The RTAPI environment RTAPI stands fo
306. update tmax The show param command shows all the parameters in the HAL Right now each parameter has the default value it was given when the component was loaded Note the column labeled Dir The parameters labeled w are writeable ones that are never changed by the component itself instead they are meant to be changed by the user to control the component We will see how to do this later Parameters labeled R are read only parameters They can be changed only by the component Finally parameter labeled RW are read write parameters That means that thay are changed by the component but can also be changed by the user Note the parameters siggen 0 update time and siggen 0 update tmax are for debugging purposes and won t be covered in this section Most realtime components export one or more functions to actually run the realtime code they contain Let s see what function s siggen exported halcmd show funct Exported Functions Owner CodeAddr Arg FP Users Name 32769 b7 74ac5 b7d0c0b4 YES 0 siggen 0 update The siggen component exported a single function It requires floating point It is not currently linked to any threads so users is zero The number after halemd in the component list is the process ID It is possible to run more than one copy of halemd at the same time in different windows for example so the PID is added to the end of the name to make it unique The codeaddr and arg fields were used in development
307. ut seventeen significant figures will be retained however enough for all known applications e A non zero number with no sign as the first character is assumed to be positive Notice that initial before the decimal point and the first non zero digit and trailing after the decimal point and the last non zero digit zeros are allowed but not required A number written with initial or trailing zeros will have the same value when it is read as if the extra zeros were not there Numbers used for specific purposes in RS274 NGC are often restricted to some finite set of values or some to some range of values In many uses decimal numbers must be close to integers this includes the values of indexes for parameters and carousel slot numbers for example M codes and G codes multiplied by ten A decimal number which is supposed be close to an integer is considered close enough if it is within 0 0001 of an integer 13 3 2 Parameter Value A parameter value is the pound character followed by a real value The real value must evaluate to an integer between 1 and 5399 The integer is a parameter number and the value of the parameter value is whatever number is stored in the numbered parameter The character takes precedence over other operations so that for example 1 2 means the number found by adding 2 to the value of parameter 1 not the value found in parameter 3 Of course 1 2 does mean the value found in parameter 3 The char
308. ute and the Actual as opposed to Commanded position CHAPTER 9 USING THE AXIS GRAPHICAL INTERFACE 93 9 3 1 Toolbar buttons From left to right the toolbar buttons are Toggle Emergency Stop also called E Stop Toggle machine power Open a file Reload the opened file Run the program Run the next line of the program Pause the program Stop the program O 0 3 O 01 F WwW NY Zoom In oO Zoom Out p p Preset view Z N Preset view Rotated Z wo Preset view X N Preset view Y al Preset view P O Clear backplot 9 3 2 Graphical Program Display Area 9 3 2 1 Coordinate Display In the upper left corner of the program display is the coordinate display It shows the position of the machine To the left of the axis name an origin symbol is shown if the axis has been properly homed To the right of the axis name a limit symbol E is shown if the axis is on one of its limit switches To properly interpret these numbers refer to the Position indicator in the status bar If the posi tion is Absolute then the displayed number is in the machine coordinate system Ifit is Relative then the displayed number is in the offset coordinate system When the coordinates displayed are relative the display will include a cyan machine origin marker If the position is Commanded
309. velocity scale 02 u32 W 000000001 freqgen 1 dirhold 02 u32 W 000000001 freqgen 1 dirsetup 02 float R 0 00000e 00 freqgen 1 frequency 02 float W 0 00000e 00 freqgen 1 maxaccel 02 float W 1 00000e 15 freqgen 1 maxfreq 02 float W 1 00000e 00 freqgen 1 position scale 02 s32 RS 0 fFreqgen 1 rawcounts 02 u32 W 000000001 freqgen 1 steplen 02 u32 W 000000001 freqgen 1 stepspace 02 float W 1 00000e 00 freqgen 1 velocity scale 7 5 2 Connecting pins with signals What we have is two step pulse generators and a signal generator Now it is time to create some HAL signals to connect the two components We are going to pretend that the two step pulse generators are driving the X and Y axis of a machine We want to move the table in circles To do this we will send a cosine signal to the X axis and a sine signal to the Y axis The siggen module creates the sine and cosine but we need wires to connect the modules together In the HAL wires are called signals We need to create two of them We can call them anything we want for this example they will be X_vel and Y_vel To create them we use the the newsig command We also need to specify the type of data that will flow through these wires in this case it is floating point halcmd newsig X vel float halcmd newsig Y vel float To make sure that worked we can look at all the signals halcmd show sig Signals Type Value Name float 0 00000e 00 X_vel float 0 0
310. will fail with a tool path contour if the tool is under sized D 2 2 Figure 12 Simpler Cutter Radius Compensation Entry Move CHAPTER 20 TOOL FILE AND COMPENSATION 168 Other Items Where Cutter Radius Compensation is Performed The complete set of canonical functions includes functions which turn cutter radius on and off so that cutter radius compensation can be performed in the controller executing the canonical functions In the interpreter however these commands are not used Compensation is done by the interpreter and reflected in the output commands which continue to direct the motion of the center of the cutter tip This simplifies the job of the motion controller while making the job of the interpreter a little harder Algorithms for Cutter Radius Compensation The interpreter allows the entry and exit moves to be arcs The behavior for the intermediate moves is the same except that some situations treated as errors in the interpreter are not treated as errors in other machine controls Data for Cutter Radius Compensation The interpreter machine model keeps three data items for cutter radius compensation the setting itself right left or off program_x and program _y The last two represent the X and Y positions which are given in the NC code while compensation is on When compensation is off these both are set to a very small number 10 20 whose symbolic value in a define is unknown The interpr
311. wiring diagram is complete it is time to build the machine The pieces need to be acquired and mounted and then they are interconnected according to the wiring diagram In a physical system each interconnection is a piece of wire that needs to be cut and connected to the appropriate terminals HAL provides a number of tools to help build a HAL system Some of the tools allow you to connect or disconnect a single wire Other tools allow you to save a complete list of all the parts wires and other information about the system so that it can be rebuilt with a single command 6 1 1 4 Testing Very few machines work right the first time While testing the builder may use a meter to see whether a limit switch is working or to measure the DC voltage going to a servo motor He may hook up an oscilloscope to check the tuning of a drive or to look for electrical noise He may find a problem that requires the wiring diagram to be changed perhaps a part needs to be connected differently or replaced with something completely different HAL provides the software equivalents of a voltmeter oscilloscope signal generator and other tools needed for testing and tuning a system The same commands used to build the system can be used to make changes as needed 6 1 2 Summary This document is aimed at people who already know how to do this kind of hardware system integration but who do not know how to connect the hardware to EMC
312. with approximately 24 bits of resolution and over 200 bits of dynamic range U32 a 32 bit unsigned integer legal values are O to 4294967295 32 a 32 bit signed integer legal values are 2147483648 to 2147483647 Function Real hardware components tend to act immediately on their inputs For example if the input voltage to a servo amp changes the output also changes automatically However software components cannot act automatically Each component has specific code that must be executed to do whatever that component is supposed to do In some cases that code simply runs as part of the component However in most cases especially in realtime components the code must run in a specific sequence and at specific intervals For example inputs should be read before calculations are performed on the input data and outputs should not be written until the calculations are done In these cases the code is made CHAPTER 6 INTRODUCTION 46 available to the system in the form of one or more functions Each function is a block of code that performs a specific action The system integrator can use threads to schedule a series of functions to be executed in a particular order and at specific time intervals Thread A thread is a list of functions that runs at specific intervals as part of a realtime task When a thread is first created it has a specific time interval period but no functions Functions can be added to the thread and will
313. with machining centers Both the RS274 NGC input language and the output canonical machining functions have a view of 1 mechanical components of a machining center being controlled and 2 what activities of the machining center may be controlled and what data is used in control The view here includes some items that a given machining center may not have such as a pallet shuttle The RS274 NGC language and canonical machining functions may be used with such a machine provided that no NC program used with the controller includes commands intended to activate physical capabilities the machine does not have For such a machine it would be useful to modify the Interpreter so it will reject input commands and will not produce output canonical function calls addressed to non existent equipment 12 1 Mechanical Components A machining center has many mechanical components that may be controlled or may affect the way in which control is exercised This section describes the subset of those components that interact with the Interpreter Mechanical components that do not interact directly with the Interpreter such as the jog buttons are not described here even if they affect control 12 1 1 Linear Axes A machining center has independent mechanisms for producing relative linear motion of the tool and workpiece in three mutually orthogonal directions These are the X Y and Z axes 12 1 2 Rotational axes Three additional independent mechanisms
314. x_pinout matches the setup for those brand of cards HALFILE core_stepper hal HALFILE standard_pinout hal HALFILE xylotex_pinout hal You can also add variables commands really here 5 3 6 TRAJ Section The TRAJ section contains general parameters for the trajectory planning module in EMCMOT You will not need to change these if you are applying EMC to a common three axis mill in the United States of America If you are in an area using metric hardware components you might be working with the stepper_mm ini where these numbers are already setup for that system of units AXES 3 The number of controlled axes in the system If you have a four axis system put that number here and edit the next two variables as well 4See the Integrator Handbook for details CHAPTER 5 INI CONFIGURATION 32 COORDINATES X Y Z The names of the axes being controlled X Y Z A B and C are all valid It is also possible to have X Y Y Z and control ganged slides For a fourth axis mounted on X you would use X Y Z A This has no effect on the mapping from G code axis names X Y Z to joint numbers kinematics does this but is largely for documentation HOME 0 0 O Coordinates of the homed position of each axis Again for a fourth axis you will need 0 0 00 This value is only used for machines with nontrivial kinematics On machines with trivial kinematics this value is ignored LINEAR_UNITS lt units gt The nam
315. xis of the helix is also specified It is an error if e both of the axis words for the axes of the selected plane are omitted e the end point of the arc is the same as the current point It is not good practice to program radius format arcs that are nearly full circles or are semicircles or nearly semicircles because a small change in the location of the end point will produce a much larger change in the location of the center of the circle and hence the middle of the arc The magnification effect is large enough that rounding error in a number can produce out of tolerance cuts Nearly full circles are outrageously bad semicircles and nearly so are only very bad Other size arcs in the range tiny to 165 degrees or 195 to 345 degrees are OK Here is an example of a radius format command to mill an arc G17 G2 x 10 y 15 r 20 z 5 That means to make a clockwise as viewed from the positive Z axis circular or helical arc whose axis is parallel to the Z axis ending where X 10 Y 15 and Z 5 with a radius of 20 If the starting value of Z is 5 this is an arc of a circle parallel to the XY plane otherwise it is a helical arc CHAPTER 14 GCODES 138 14 3 2 Center format arcs In the center format the coordinates of the end point of the arc in the selected plane are specified along with the offsets of the center of the arc from the current location In this format it is OK if the end point of the arc is the same as the current p
316. xpects of a file It will also allow you to CHAPTER 11 USING THE MINI GRAPHICAL INTERFACE 118 cut and paste from one part of a file to another In addition it will allow you to save your changes and submit them to the EMC interpreter with the same menu click You can work on a file in here for a while and then save and load if the EMC is in Auto mode If you have been running a file and find that you need to edit it that file will be placed in the editor when you click on the editor button on the top menu 11 6 2 Backplot Display x Y X Z Z 3D Hide Setup Figure 11 6 Mini s Backplotter Backplot Backplot will show the tool path that can be viewed from a chosen direction 3 D is the default Other choices and controls are displayed along the top and right side of the pop in If you are in the middle of a cut when you press one of these control buttons the machine will pause long enough to re compute the view Along the right side of the pop in there is a small pyramid shaped graphic that tries to show the angle you are viewing the tool path from Below it are a series of sliders that allow you to change the angle of view and the size of the plot You can rotate the little position angle display with these They take effect when you press the Refresh button The Reset button removes all of the paths from the display and readies it for a new run of the program but retains your settings for that session If bac
317. ying to remember which one you tried last time If you look closer at the listing of available configurations you will see that they are divided into main sections that show where those configurations are located in the file system Your configuration selector will show a different set of configurations that the one shown in Figure 3 1 because this selector looks for and finds these configurations in both the etc emc2 directory and a user s home directory In this case it shows all of the configurations it found in home rayh emc2 configs as well as those samples found in etc emc2 It is far easier to find a sample configuration that is close to what is required for a specific machine and then editing that sample to exactly fit the axis ratios and IO buttons and relays than it is to lWe recommend making a copy of the sample configuration needed by a user in the home directory as emc2 configs myconfig If a user leaves the sample configurations intact in etc emc2 they can always make a new copy for editing 18 CHAPTER 3 RUNNING EMC2 19 Figure 3 1 EMC2 Configuration Selector EMC2 Configuration Selector Welcome to EMC2 Select a machine configuration from the list on the left Details about the selected configuration will appear in the display on the right Click OK to run the selected configuration homefrayh emc2 configs demo_step_cl motenc sim axis mini tkemce stepper E stepper_inch stepper_mm fetc emc2 sample

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