CNC USB Controller. User manual

Transcription

1 CNC USB Controller User manual

2 Table of Contents 1 2 Introduction Overview System Requirements...8 Hardware Specification and features Board description Installation Motor connector Connector connector Jog connector Limit connector Stop jumper VUSB jumper VEXT jumper V power connector (green) Software Overview Main window Position panel State panel Program panel Graphical program visualization display G-code panel Manual data input (MDI) panel Toolbar File menu Open Close Recent Files Import DXF Import Image Import Text Export Toolpath To G-code

3 Export Toolpath to DXF Export Toolpath to CSV Settings Language Exit View menu Origin Top View Side View Front View Perspective View Zoom In Zoom Out Zoom Tool Zoom Extents Center Tool Center View Change View Simulate Show Material Program menu Select Origin Bookmarks Shift Scale Mirror Rotate Swap XYZ UVW Convert Arcs To Lines Convert To Lines Machine menu Emergency Stop Start Stop Pause Bookmarks Mist Flood Spindle

4 Go To Position Set Position Home Tool length here Tool length Firmware Help menu Help Activate License Import License Export License Log About Status bar Settings General Units Axes Speed Jog Misc Axes Axes Acceleration Backlash Axes Park Positions Limits Homing Tools Tool Change Tool Change Tool Length Spindle Materials Parameters FAQ Firmware Update Manual zeroing Homing procedure Tool Length procedure

5 4 G-Code Overview Format of a Line Line Number Word Number Parameters Expressions and Binary Operations Unary Operation Value Comments and Messages Item Repeats Item Order Modal and Non-modal modes Modal Groups G - Codes G00 - Rapid Positioning (Linear Motion at Traverse Rate) G01 - Linear Interpolation (Linear Motion at Feed Rate) G02 - Circular/Helical Interpolation (CW) G03 - Circular/Helical Interpolation (CCW) (Arc at Feed Rate) G04 - Dwell G10 L1 Set Tool Table G10 L2 - Coordinate System Origin Setting G10 L9 Set Machine Position Without Move G17 - XY-Plane Selection G18 - XZ-Plane Selection G19 - YZ-Plane Selection G20 - Inch System Selection G21 - Millimeter System Selection G28 - Return to Home G30 - Return to Secondary Home G Straight Probe G40 - Cancel Cutter Radius Compensation G41 - Start Cutter Radius Compensation Left G42 - Start Cutter Radius Compensation Right G43 - Tool Length Offset G49 - Cancel Tool Length Offset G53 - Motion in Machine Absolute Coordinates G54 - Use Preset Work Coordinate System G55 - Use Preset Work Coordinate System G56 - Use Preset Work Coordinate System

6 G57 - Use Preset Work Coordinate System G58 - Use Preset Work Coordinate System G59 - Use Preset Work Coordinate System G Use Preset Work Coordinate System G Use Preset Work Coordinate System G Use Preset Work Coordinate System G61 - Set Path Control Mode: Exact Path...50 G set Path Control Mode: Exact Stop...50 G64 - Set Path Control Mode: Continuous...50 G80 - Cancel Motion Mode (Including any Canned Cycle)...50 Canned Cycles (G80 - G89)...51 G81 - Canned Cycle: Drilling...52 G82 - Canned Cycle: Drilling with Dwell...54 G83 - Canned Cycle: Peck Drilling...54 G84 - Canned Cycle: Right Hand Tapping...54 G85 - Canned Cycle: Boring, No Dwell, Feed Out...55 G86 - Canned Cycle: Boring, Spindle Stop, Rapid Out...55 G87 - Canned Cycle: Back Boring...55 G88 - Canned Cycle: Boring, Spindle Stop, Manual Out...56 G89 - Canned Cycle: Boring, Dwell, Feed Out...57 G90 - Absolute Distance Mode...57 G91 - Incremental Distance Mode...57 G92 - Offset Coordinate Systems and Set Parameters...57 G Cancel Offset Coordinate Systems and Set Parameters to Zero...58 G Cancel Offset Coordinate Systems But Do Not Reset Parameters...58 G Apply Parameters to Offset Coordinate Systems...58 G93 - Inverse Time Feed Rate Mode...58 G94 - Units Per Minute Feed Rate Mode...59 G98 - Initial level Return in Canned Cycles...59 G99 R-point Level Return in Canned Cycles M - Codes M0 - Program Stop M1 - Optional Program Stop M2 - Program End M30 - Program End, Pallet Shuttle, and Reset M60 - Pallet Shuttle and Program Stop M3 - Turn Spindle Clockwise M4 - Turn Spindle Counterclockwise M5 - Stop Spindle Turning M6 - Tool Change M7 - Mist Coolant On M8 - Flood Coolant On M9 - Mist and Flood Coolant Off

7 M48 - Enable Speed and Feed Overrides...60 M49 - Disable Speed and Feed Overrides Other Codes F - Set Feed Rate S - Set Spindle Speed T - Select Tool Sample G-code programs Square Circle One side of a ball in cage

8 1 Introduction 1.1 Overview CNC motion controller is a link between personal computer and drivers for stepper motors. It uses USB port which is available on all modern computers and laptops. This is a complete (software/hardware) solution and it does NOT require any additional software. USB CNC controller is compatible with most step/dir drivers. It can be used as direct replacement for many parallel port break-out boards. 1.2 System Requirements Minimum system requirements: 1 GHz or faster processor 512MB RAM 500 MB available hard disk space DirectX 9 graphics device with WDDM 1.0 or higher driver USB 2.0 port.net Framework 3.5 SP1 Recommended system requirements: 2 GHz or faster processor 2GB RAM 500 MB available hard disk space DirectX 9 graphics device with WDDM 1.0 or higher driver USB 2.0 port.net Framework 3.5 SP1 8

9 2 Hardware 2.1 Specification and features 4 axes USB CNC controller USB (V2.x) from PC/Laptop motor driver connector pin-out is compatible with 10 pin open source interface controller works with most motor drivers available on the market 3 digital outputs (flood, mist, spindle) 25 khz maximum step frequency 12 us minimum pulse width buffered IO for maximum performance advanced interpolation algorithms two manual jog input keys per axis (8 total) two limit keys per axis (8 total) pause/resume of execution supported automatic homing procedure advanced toolchange procedures standard RS274/NGC G-code (EMC2 compatible) toolpath simulation advanced G-codes - G40, G41, G42 (Cutter Radius Compensation) supported advanced G-codes - G43, G49 (Tool Length Offsets) supported advanced G-codes - G54, G59.3 (Coordinate System Origins) supported tested with SolidCAM, MasterCAM, ArtCAM, Vectric,... generated G-code Profili 4-axes and 3-axes G-code supported import toolpath from DXF file import toolpath from PLT/HPGL file import toolpath from image file export toolpath to G-code export toolpath to DXF SDK (software developers kit) is available 9

10 2.2 Board description 10

11 2.3 Installation Controller must be connected to motor drivers which drive motors. Computer is connected to USB connector. IMPORTANT: Do not connect controller to USB without supplying power. Either place 5VUSB jumper or an alternative power source. See power options described below Motor connector +5VEX 5V power of motor driver. This pin can be used to power motor driver from controller or to power controller from motor driver. 5VEX jumper on controller must be closed to enable this connection. STEP Step signal for motor driver. Width of signal is 12uS or more. DIR Direction signal for motor driver. ENABLE Enable signal for motor driver. Controller does not control this pin. It just connect them together and provides possibility to easily connect emergency stop switch. You can connect emergency stop switch to to stop pin on Connector connector. 11

12 2.3.2 Connector connector STOP use this pin to connect emergency switch. This is same as Stop jumper. See Motor connector ENABLE pin for more information. OUT1 this pin is controlled with spindle commands OUT2 this pin is controlled with flood coolant commands OUT3 this pin is controlled with mist coolant commands RESET connect this pin to GND to reset controller (same as Reset button) LED use this pin to connect external blinking LED. You must use current limiting resistor to limit current to 10mA. POT connect 5k or 10k ohm, logaritmic taper potentiometer to this pin to controll speed of manual jogging. +5V 5V power supply for potentiometer 12

13 2.3.3 Jog connector JOG 1-8 for connecting jog keys. It is recommended that you put 100nF capacitor directly to key teminals. Typical connection is: JOG1 X- axis JOG2 X+ axis JOG3 Y- axis JOG4 Y+ axis JOG5 Z- axis JOG6 Z+ axis JOG7 A- axis JOG8 A+ axis Limit connector LIMIT 1-8 for connecting limit switches. It is recommended that you put 100nF capacitor directly to key teminals. Typical connection is: LIMIT1 X- axis LIMIT2 X+ axis LIMIT3 Y- axis LIMIT4 Y+ axis LIMIT5 Z- axis LIMIT6 Z+ axis LIMIT7 A- axis LIMIT8 A+ axis 13

14 2.3.5 Stop jumper Close this jumper if your motor drivers support ENABLE signal and you don't want to use it VUSB jumper Close this jumper to power controller from USB. When closed, 5V power connector (green) must not be connected. When closed, 5VEXT jumper must be open unless you want to power motor drivers through controller VEXT jumper Close this jumper to power controller from motor drivers or to power motor drivers. Use only if you know what you're doing. Incorrect usage may damage controller and/or drivers V power connector (green) Use this connector to power controller with external 5V power supply. WARNING: CHECK POLARITY AND VOLTAGE Controller is not protected against wrong polarity or voltage. When in use, 5VUSB jumper must be open. When in use, 5VEXT jumper must be open unless you want to power motor drivers through controller. 14

15 3 Software 3.1 Overview CNC USB Controller software is specialy designed to work with controller. All controller functions are accesible through software. Software is designed to be simple and friendly to new users. 3.2 Main window Components of main window are: A position, state and program panels B graphical program visualization display C G-code panel D manual data input (MDI) panel E menus and toolbars F status bar 15

16 3.2.1 Position panel Position panel main features are: Current machine position coordinates Zero buttons Current machine speed Jog buttons Speed override control Current machine position coordinates are displayed based on selected coordinate system. To display machine absolute coordinates check Absolute option. Zero buttons are used to set position to zero for one of for all axes. Speed is displayed in 'default units per minute'. Default units are set in settings. Jog buttons are used to move machine to desired position. Jogging speed is set with speed override slider. Speed override value is set with slider. Currrent value is displayed above slider. Speed override is used only when it is enabled with check box next to slider. 16

17 3.2.2 State panel State panel shows information about: Current machine state Program simulation state Displayed informations are: Units millimeters or inches Plane XY, YZ or ZX Mode absolute or relative Feed, Traverse - speed Flood, Mist, Spindle - output Axes coordinates Offset current origin and coordinates Tool tool number and offsets Line G-code line number Program panel Program panel shows information about loaded program. Name name of program Units units used in this panel Min, Max minimum and maximum values used in program (program extents) Min Feed, Max Feed minimum and maximum values used for feed moves in program (cutting extents) Length length of toolpath Time estimated time needed to execute program Time (O) estimated time needed to execute program if using speed override 17

18 3.2.4 Graphical program visualization display This display shows 3D representation of machine, tool, toolpath,... Orange box machine limits Gray grid machine table Axis arrows displayed coordinate system origin Red axis lines selected coordinate system origin White line feed toolpath Cyan line traverse toolpath Red line selected toolpath section Yellow cone current machine position Orange cone simulated position Dark green/gray cone G28 and G30 positions Dark green/gray program extents and program cutting extents G-code panel G-code panel shows current program lines. Lines are numbered. Red lines represent pause. Machine willl pause execution at these lines, Lines with dark red line number are bookmarked Manual data input (MDI) panel MDI is text input box, which allows manual G-code input. For example typing G0 X100 will move machine at traverse rate to X100 position. 18

19 3.2.7 Toolbar Toolbar has buttons for quick access to: Emergency stop Open program Start executing program Stop program execution Pause program execution Top View - display program as viewed from top Side View - display program as viewed from side Front View - display program as viewed from front Perspective View - display program in perspective Zoom In - zoom in display to view details Zoom Out - zoom out display to view larger part Center View - center display at program origin File menu Open Open new G-code, DXF or image file. Application will create toolpath and machine program from this file Close Close currently open program Recent Files Display a list of recently opened files Import DXF Open new DXF file. After file is selected, following parameters should be specified: Height safe height of tool to move from one element to another Scale scale of opened image according to original size, Sort should be toolpath optimized (to avoid unnecessary moves of tool). Application will create toolpath and machine program from this file. 19

20 Import Image Open new image file. After image is selected, following parameters should be specified: Size size of piece Height safe height of tool Invert positive or negative relief Diameter diameter of used tool Detail interpolation detail level Method parameter, on which depends the height (R Red, G Green, B Blue, H Hue, S Saturation, L Lightness) Application will create toolpath and machine program from this file according to selected method Import Text After text is submitted, following parameters should be specified: Height safe height of tool to move from one element to another Scale scale of opened image according to original size, Sort should be toolpath optimized (to avoid unnecessary moves of tool). Application will create toolpath and machine program from written text Export Toolpath To G-code Export toolpath to G-code file. Extension of file should be written manually Export Toolpath to DXF Export toolpath to DXF file. Created sketch contains all tool paths, including moves of tool from one element to another on safe height Export Toolpath to CSV Export toolpath to CSV file. Created list of points contains points, that are visited during program execution Settings Display settings dialog, where general settings, axes, used tools, tool changes, used materials and coordinate systems are specified (see 3.3) Language Select language of application from list of supported languages Exit Exit application. 20

21 3.2.9 View menu Origin Show defined origins on display Top View Display program as viewed from top Side View Display program as viewed from side Front View Display program as viewed from front Perspective View Display program in perspective Zoom In Zoom in display to view details Zoom Out Zoom out display to view larger part Zoom Tool Center and zoom display to view detail at current tool position Zoom Extents Center and zoom display to view whole program Center Tool Center display at current tool position Center View Center display at program origin Change View Switch between horizontal and vertical position of G-code panel Simulate Animate simulation tool handle on display. 21

22 Show Grid show/hide grid Axes show/hide axes Working Area show/hide machine working area Tool show/hide tool Tool Handle show/hide tool handle. Only small tool is visible on display when tool handle is not shown.. Tool G28, G30 show/hide G28 and G30 positions. Extents show/hide box representing program extents. Projection toggles between orthogonal and perspective projection Material Show defined materials to select one of them. Properties of selected material are used for tool length measurement. Materials are specified in Settings (see 3.3.6). You can show material in wireframe or solid mode. In solid mode material texture is based on material type. 22

23 Program menu Select Origin Select origin and set it as current origin Bookmarks Select bookmarked G-code lines and set/clear bookmark. Use of bookmarks is specified in section Shift Shift G-code program. Examples: X: 10, will be added to coordinate X (program moves to right) X: -10, will be subtracted from coordinate X (program moves to left) One of following options can be selected: User for each used coordinate can be inserted value to shift program Extends to Zero program will be moved to position zero Extends to Position program will be moved to current tool position Scale Scale G-code program. For each axis in use insert a factor for scale a program. Examples: X: 4,000 coordinate X is multiplied by factor Mirror Mirror G-code program according to selected axis. Program will remain at current position Rotate Rotate G-code program in selected plain by entered degree value Swap XYZ UVW Swap X, Y and Z coordinates with U, V and W. This is used in 4-axis hot wire machines. Example: Program is made to create left wing of plane. By use of swap command existing program creates right wing of plane Convert Arcs To Lines Convert arc moves to line moves Convert To Lines Convert program to line moves. 23

24 Machine menu Emergency Stop Immediately send STOP commands to controller and stops executing program Start Start executing program Stop Stop executing program Pause Pause or resume execution of program Bookmarks Start executing program based on bookmarks: Start - Only Bookmarked only bookmared lines will be executed Start - Skip Bookmarked bookmarked lines will not be executed Start - From Begining To Bookmark execution will end at first bookmark Start - From Bookmark To End execution will start at first bookmark Mist Mist output will be turned on or off Flood Flood output will be turned on or off Spindle Spindle output will be turned on or off Go To Position Move machine to specified position: Zero Absolute machine zero Park 1 Park 1 position Park 2 Park 2 position G28 G28 position G30 G30 position User User defined position 24

25 Set Position Set machine current position to value: Zero Absolute machine zero Park 1 Park 1 position Park 2 Park 2 position G28 G28 position G30 G30 position User User defined position Home Execute homing procedure Tool length here Measures tool length at current XY position Tool length Execute tool length procedure Firmware Manually update or verify controller firmware. 25

26 Help menu Help menu includes links to useful external web sites Help Open user manual Activate License Open program license activation window Import License Import license from file Export License Export license to file Log Open program log window. This is used when diagnosing problems About Display about window which includes information about software version, firmware version and hardware serial number if available Status bar Status bar displays controller buffer state, progress status and some other useful information. 26

27 3.3 Settings All machine settings and parameters are set in settings dialog General Units Set machine default units. All settings will use this units. On change of units all values will be recalculated Axes Set Number of Axis that you use. If your controller does not support so many axes they will be ignored. Assign Axis Name to each axis. Most common names for 4-axis machine are X, Y, Z and A. Hot wire machines usually use X, Y, U and V. Common used names of axes: X, Y, Z normal axes A, B, C rotary axes U, V, W parallel axes (hot wire machine) Speed Set default Feed and Traverse speed in 'units per minute': Feed speed speed of machine working in material Traverse speed speed of machine moving on safe height to next position This speed will be used unless program uses F word to specify speed or speed override is selected. If Override is checked software will start with override enabled. If Override Feed Only is checked only feed moves will be overridden and traverse moves will use default speed. 27

28 Jog Set jog Distance and maximum jog speed. Distance is length that machine will travel on one single short click. Max Speed sets value of speed when jog speed potentiometer is in maximal position Misc Set Machine Type for proper visualization on display: XYZ classic mill or router style machine Hot wire 4-axis foam cutting style machine Rotary machine with rotary A axis XY-UV Distance is distance between XY and UV plane on Hot Wire machine type. Display Resolution sets detail level of display. Setting this to low value will degrade performance. Lookahead Angle is used for calculating speed. If angle between two moves is larger than this value machine will move without lowering speed. If angle between two moves is less than this value machine will have to lower speed. This is displayed on G-code panel with ' ' and ' ' mark. Optimization Threshold will set maximum detail level before optimization. Program will try to remove lines shorter than specified length. Setting this too low will produce jerky machine movement. With Microstepping you tell controller, what microstepping your motor drivers use. Select closest available value. USB Resend is used only for diagnostics. 28

29 3.3.2 Axes Axes Steps/Unit is most important settings. Set its value tu number of steps that your machine needs for one unit of travel. This depends of motor, motor driver and screw. Reverse will reverse motor direction. Invert Pulse is used with some motor drivers which require 'negative' pulse Acceleration Set acceleration profile fom moves. Move will begin with Initial speed (units per minute) and will accelerate to target speed with Acceleration (units per second^2). Maximum speed that is allowed can also be set Backlash Axes Park Positions Set Park1 and Park2 positions. These can be used for many different things such as manual homing, tool change, Limits Limit switch checkbox sets if positive or negative limit switch is used on machine. If limit switch is used and it is hit during machine movement machine will stop. Exception are hardware jog buttons which move machine regardless on limit switch and special procedures which use switches for special purposes. Limit+ and Limit- are used to display machine limits on 3D display panel. 29

30 Homing These settings are for automatic homing procedure. Speed is machine speed used for this procedure. Direction sets if positive or negative direction is used. Sequence sets order in which axes are homed. '----' means that axis is not homed. Set Position will be set when limit switch is hit. Go To will move machine to this position afterwards. Homing procedure will move specified axes to 'home' position. Set Sequence to specify axis order. Usually Z axis moves first, X and Y move second, other axes are not moved. Axis will move with set Speed and Direction until limit switch is hit. When switch is hit Set Position will set coordinates of limit switch. After this, machine will Go To specified coordinates. 30

31 3.3.4 Tools Tool table settings: Number number of tool Name name if tool Description tool description Tool Shape tool shape Diameter tool diameter Z Offset Z axis offset for tool length compensation X Offset X axis offset for tool length compensation Orientation tool orientation Tool Change position for tool change procedure Update button updates selected tool with new data. Add button adds new tool to tool table. Remove button removes tool from tool table. 31

32 3.3.5 Tool Change Tool Change These settings determine what should machine do when toolchange command (M6) is executed. Position sets where toolchange should occur. Z Axis First will move Z axis before other axis so that movement is done at safe height. Z Axis Only will move only Z axis. When you change tool manualy this is usualy enough. Pause will pause machine at tool change. This will give you time to change tool. Tool length will start tool length measurment procedure after tool change. Auto Return will return machine to position before tool change after tool change is completed. Auto Compensate will automaticaly adjust tool offset if tool length compensation (G43) is active Leave Spindle On will not turn spindle off at tool change. Skip Already Active will not perform tool change if tool is already active. Use Default Tool will use tool with number zero if requested tool is not in tool table. Initial tool is tool number that is already mounted and active on machine at begining Tool Length These settings determine how tool length procedure measures tool length. Location is absolute coordinate of tool length sensor. Speed is machine speed used for this procedure. Direction sets if positive or negative Z direction is used. Set Position is Z offset position of sensor (height of sensor). Use Material will add offset from material table (material Z position + material Z size) Return will move machine to position before tool length procedure. Pause will pause machine at tool length Spindle Set Pause if you want machine to pause on spindle commands. This is can be used if you turn spindle on or off manually. 32

33 3.3.6 Materials Material table is used for display and for offset in tool length procedure. Number number of material Name name if material Description material description Kind specify material kind Size set material size Position set material position in absolute coordinates Update button updates selected material with new data. Add button adds new material to material table. Remove button removes material from material table. 33

34 3.3.7 Parameters Parameter table is used for setting varous parameters such as coordinate system, G28 and G30 position, G92 offset. See G-code section for more information. Update button updates selected parameter with new data. Reset button resets parameter to default value. 34

35 3.4 FAQ Firmware Update Software will detect wrong firmware and will offer an option to update it. You can also update firmware manually with Machine/Firmware/Update and verify it with Machine/Firmware/Verify commands Manual zeroing Use commands Machine/Go To Position and Machine/Set Position to manually zero machine Homing procedure Use commands Machine/Home to execute homing procedure Tool Length procedure Use commands Machine/Tool Length or Machine/Tool Length here to start tool length measuring procedure. In tool length procedure machine will move Z axis down (or up) until Limit Z switch is triggered. Here is an example how to connect tool length switch made from piece of PCB. connect GND pin of Limit connector to toolbit. Usualy it is enough to connect it do spindle holder connect Limit Z- pin (LIMIT 5) to a piece of copper PCB 35

36 4 G-Code G-code interpreter used by CNC USB controller is implemented according to National Institute of Standards and Technology RS274NGC Interpreter - Version 3 specification. Full documentation of RS274NGC is available at web page: 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 the end of the move). Most RS274/NGC commands start with either G or M (for 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 nonblank 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 signaled 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. 4.2 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. 36

37 1. an optional block delete character, which is a slash "/". 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. 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 y 7" is equivalent to "g0 x y7", for example. Blank lines are allowed in the input. They are to be ignored. Input is case insensitive, except in comments. Any letter outside a comment may be in upper or lower case without changing the meaning of a line. 4.3 Line Number A line number is the letter N followed by an integer (with no sign) between 0 and written with no more than five digits ( 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. 4.4 Word A word is a letter other than N followed by a real value. Words may begin with any of the letters shown below. Several letters (I, J, K, L, P, R) may have different meanings in different contexts. Permitted letters are: A, B, C, D, F, G, H, I, J, K, L, M, N, P. Q, R, S, T, X, Y, Z 4.5 Number A real value is some collection of characters that can be processed to come up with a number. A real value may be an explicit number (such as 341 or ), a parameter value, an expression, or a unary operation value. Definitions of these follow immediately. Processing characters to come up with a number is called "evaluating". An explicit number evaluates to itself. The following rules are used for (explicit) numbers. In these rules a digit is a single character between 0 and 9. 37

38 A number consists of an optional plus or minus sign, followed by zero to many digits, followed, possibly, by one decimal point, followed by zero to many digits - provided that there is at least one digit somewhere in the number. There are two kinds of numbers: integers and decimals. An integer does not have a decimal point in it, a decimal does. Numbers may have any number of digits, subject to the limitation on line length. Only about seventeen significant figures will be retained, however (enough for all known applications). 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 of an integer. 4.6 Parameters A parameter value is the pound character # followed by a real value. The real value must evaluate to an integer between 1 and 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 # character may be repeated; for example ##2 means the value of the parameter whose index is the (integer) value of parameter 2. 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." 38

39 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 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 + cos[0] - [#3 ** [4.0/2]]]. Binary operations appear only inside expressions. Nine binary operations are defined. 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 (**) of raising the number on the left of the operation to the power on the right. 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 exclusive or, and logical and. If operations are strung together (for example in the expression [2.0 / 3 * / 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) * 1.5) - (5.5 / 11.0)], which simplifies to [ ], 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. 4.8 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 39

40 power), FIX (round down), FUP (round up), LN (natural logarithm), ROUND (round to the nearest whole number), SIN (sine), SQRT (square root), and TAN (tangent). Arguments to unary operations which take angle measures (COS, SIN, and TAN) are in degrees. Values returned 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. 4.9 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 comment. 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 Item Repeats A line may have any number of G words, but two G words from the same modal group 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. 40

41 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 that putting more than one comment on a line will be very rare 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 g1 #3=15 g40 (foo)") for the five items Modal and Non-modal modes In RS274/NGC, many commands cause a machining center to change from one 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 canceling motion. 41

42 "Non-modal" codes have effect only on the lines on which they occur. For example, G4 (dwell) is non-modal 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 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 for G codes are: group 1 = {G0, G1, G2, G3, G38.2, G80, G81, G82, G83, G84, G85, G86, G87, G88, G89} motion group 2 = {G17, G18, G19} plane selection group 3 = {G90, G91} distance mode group 5 = {G93, G94} feed rate mode group 6 = {G20, G21} units group 7 = {G40, G41, G42} cutter radius compensation group 8 = {G43, G49} tool length offset group 10 = {G98, G99} return mode in canned cycles group 12 = {G54, G55, G56, G57, G58, G59, G59.1, G59.2, G59.3} coordinate system selection group 13 = {G61, G61.1, G64} path control mode The modal groups for M codes are: group 4 = {M0, M1, M2, M30, M60} stopping group 6 = {M6} tool change group 7 = {M3, M4, M5} spindle turning group 8 = {M7, M8, M9} coolant (special case: M7 and M8 may be active at the same time) group 9 = {M48, M49} enable/disable feed and speed override switches In addition to the above modal groups, there is a group for non-modal G codes: group 0 = {G4, G10, G28, G30, G53, G92, G92.1, G92.2, G92.3} 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. 42

43 It is an error to put a G-code from group 1 and a G-code from group 0 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 0 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 0 are G10, G28, G30, and G G - Codes G-codes of the RS274/NGC language are shown and described below G00 - Rapid Positioning (Linear Motion at Traverse Rate) For rapid linear motion, program G0 X- 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 G0. 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 G0 command is executing. It is an error if: all axis words are omitted. If cutter radius compensation is active, the motion will differ from the above G01 - Linear Interpolation (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 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: all axis words are omitted. If cutter radius compensation is active, the motion will differ from the above. 43

44 G02 - Circular/Helical Interpolation (CW) G03 - Circular/Helical Interpolation (CCW) (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, 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. 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. Radius Format Arc 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 degrees. If the arc is helical, the value of the end point of the arc on the coordinate axis parallel to the axis of the helix is also specified. It is an error if: both of the axis words for the axes of the selected plane are omitted, 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. 44

45 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. Center Format Arc 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 point. It is an error if: 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 inch (if inches are being used) or 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: X and Y are both omitted, 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: X and Z are both omitted, I and 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 of the circle. J and K are optional except that at least one of the two must be used. It is an error if: Y and Z are both omitted, J and K are both omitted. 45