INI Configuration

[EMC] general information

[DISPLAY] settings related to the graphical user interface

[FILTER] settings input filter programs

[RS274NGC] settings used by the g-code interpreter

[EMCMOT] settings used by the real time motion controller

[TASK] settings used by the task controller

[HAL] specifies .hal files

[HALUI] MDI commands used by HALUI

[APPLICATIONS] Other applications to be started by LinuxCNC

[TRAJ] additional settings used by the real time motion controller

[JOINT_n] individual joint variables

[AXIS_n] individual axis variables

[KINS] kinematics variables

[EMCIO] settings used by the I/O Controller

a file in the same directory as the INI file

a file located relative to the working directory

an absolute file name (starts with a /)

a user-home-relative file name (starts with a ~)

VERSION = 1.1 - The version number for the configuration. Any value other than 1.1 will cause the configuration checker to run and try to update the configuration to the new style joint axes type of configuration.

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.

DEBUG = 0 - Debug level 0 means no messages will be printed when LinuxCNC is run from a terminal. Debug flags are usually only useful to developers. See src/emc/nml_intf/debugflags.h for other settings.

DISPLAY = axis - The name of the user interface to use. Valid options may include: axis, touchy, gmoccapy, gscreen, tklinuxcnc, qtvcp

POSITION_OFFSET = RELATIVE - The coordinate system (RELATIVE or MACHINE) to show on the DRO when the user interface starts. The RELATIVE coordinate system reflects the G92 and G5x coordinate offsets currently in effect.

POSITION_FEEDBACK = COMMANDED - The coordinate value (COMMANDED or ACTUAL) to show on the DRO when the user interface starts. In Axis this can be changed from the View menu. The COMMANDED position is the position requested by LinuxCNC. The ACTUAL position is the feedback position of the motors if they have feedback like most servo systems. Typically the COMMANDED value is used.

DRO_FORMAT_MM = %+08.6f - Over-ride the default DRO formatting in metric mode. (normally 3 decimal places, padded with spaces to 6 digits to the left) the example above will pad with zeros, display 6 decimal digits and force display of a + sign for positive numbers. Formatting follows Python practice. https://docs.python.org/2/library/string.html#format-specification-mini-language an error will be raised if the format can not accept a floating-point value.

DRO_FORMAT_IN = % 4.1f - Over-ride the default DRO formatting in imperial mode. (normally 4 decimal places, padded with spaces to 6 digits to the left) the example above will display only one decimal digit. Formatting follows Python practice. https://docs.python.org/2/library/string.html#format-specification-mini-language An error will be raised if the format can not accept a floating-point value.

CONE_BASESIZE = .25 - Over-ride the default cone/tool base size of .5 in the graphics display

MAX_FEED_OVERRIDE = 1.2 - The maximum feed override the user may select. 1.2 means 120% of the programmed feed rate.

MIN_SPINDLE_OVERRIDE = 0.5 - The minimum spindle override the user may select. 0.5 means 50% of the programmed spindle speed. (This is used to set the minimum spindle speed).

MIN_SPINDLE_0_OVERRIDE = 0.5- The minimum spindle override the user may select. 0.5 means 50% of the programmed spindle speed. (This is used to set the minimum spindle speed). On multi spindle machine there will be entries for each spindle number. Qtvcp only

MAX_SPINDLE_OVERRIDE = 1.0 - The maximum spindle override the user may select. 1.0 means 100% of the programmed spindle speed.

MAX_SPINDLE_0_OVERRIDE = 1.0 - The maximum feed override the user may select. 1.2 means 120% of the programmed feed rate. On multi spindle machine there will be entries for each spindle number. Qtvcp only

DEFAULT_SPINDLE_SPEED = 100 - The default spindle RPM when the spindle is started in manual mode. if this setting is not present, this defaults to 1 RPM for AXIS and 300 RPM for gmoccapy.

DEFAULT_SPINDLE_0_SPEED = 100 - The default spindle RPM when the spindle is started in manual mode. On multi spindle machine there will be entries for each spindle number. Qtvcp only

SPINDLE_INCREMENT = 200 - The increment used when clicking increase/decrease buttons Qtvcp only

MIN_SPINDLE_0_SPEED = 1000 - The minimum RPM that can be manually selected. On multi spindle machine there will be entries for each spindle number. Qtvcp only

MAX_SPINDLE_0_SPEED = 20000 - The maximum RPM that can be manually selected. On multi spindle machine there will be entries for each spindle number. Qtvcp only

PROGRAM_PREFIX = ~/linuxcnc/nc_files - The default location for g-code files and the location for user-defined M-codes. This location is searched for the file name before the subroutine path and user M path if specified in the [RS274NGC] section.

INTRO_GRAPHIC = emc2.gif - The image shown on the splash screen.

INTRO_TIME = 5 - The maximum time to show the splash screen, in seconds.

CYCLE_TIME = 100 - Cycle time of the Display GUI. Depending on the screen, this can be in seconds or ms (ms preferred). This is often the update rate rather then sleep time between updates. If the update time is not set right the screen can become unresponsive or very jerky. A value of 100ms (0.1 seconds) is a common setting though a range of 50 - 200ms (.05 - .2 seconds) may be useable. An under powered CPU may see improvement with a longer setting. Usually the default is fine.

EMBED_TAB_NAME=GladeVCP demo

DEFAULT_LINEAR_VELOCITY = .25 - The default velocity for linear jogs, in , machine units per second.

MIN_VELOCITY = .01 - The approximate lowest value the jog slider.

MAX_LINEAR_VELOCITY = 1.0 - The maximum velocity for linear jogs, in machine units per second.

MIN_LINEAR_VELOCITY = .01 - The approximate lowest value the jog slider.

DEFAULT_ANGULAR_VELOCITY = .25 - The default velocity for angular jogs, in machine units per second.

MIN_ANGULAR_VELOCITY = .01 - The approximate lowest value the angular jog slider.

MAX_ANGULAR_VELOCITY = 1.0 - The maximum velocity for angular jogs, in machine units per second.

INCREMENTS = 1 mm, .5 in, … - Defines the increments available for incremental jogs. The INCREMENTS can be used to override the default. The values can be decimal numbers (e.g., 0.1000) or fractional numbers (e.g., 1/16), optionally followed by a unit (cm, mm, um, inch, in or mil). If a unit is not specified the machine unit is assumed. Metric and imperial distances may be mixed: INCREMENTS = 1 inch, 1 mil, 1 cm, 1 mm, 1 um is a valid entry.

GRIDS = 10 mm, 1 in, … - Defines the preset values for grid lines. The value is interpreted the same way as INCREMENTS.

OPEN_FILE = /full/path/to/file.ngc - The file to show in the preview plot when AXIS starts. Use a blank string "" and no file will be loaded at start up. gmoccapy will not use this setting, as it offers a corresponding entry on its settings page.

EDITOR = gedit - The editor to use when selecting File > Edit to edit the G code from the AXIS menu. This must be configured for this menu item to work. Another valid entry is gnome-terminal -e vim. This entry does not apply to gmoccapy, as gmoccapy has an integrated editor.

TOOL_EDITOR = tooledit - The editor to use when editing the tool table (for example by selecting "File > Edit tool table…" in Axis). Other valid entries are "gedit", "gnome-terminal -e vim", and "gvim". This entry does not apply to gmoccapy, as gmoccapy has an integrated editor.

PYVCP = /filename.xml - The PyVCP panel description file. See the PyVCP Chapter for more information.

PYVCP_POSITION = BOTTOM - The placement of the PyVCP panel in the AXIS user interface. If this variable is omitted the panel will default to the right side. The only valid alternative is BOTTOM. See the PyVCP Chapter for more information.

LATHE = 1 - Any non-empty value (including "0") causes axis to use "lathe mode" with a top view and with Radius and Diameter on the DRO.

BACK_TOOL_LATHE = 1 - Any non-empty value (including "0") causes axis to use "back tool lathe mode" with inverted X axis.

FOAM = 1 - Any non-empty value (including "0") causes axis to change the display for foam-cutter mode.

GEOMETRY = XYZABCUVW - Controls the preview and backplot of motion. This item consists of a sequence of axis letters and control characters:

ARCDIVISION = 64 - Set the quality of preview of arcs. Arcs are previewed by dividing them into a number of straight lines; a semicircle is divided into ARCDIVISION parts. Larger values give a more accurate preview, but take longer to load and result in a more sluggish display. Smaller values give a less accurate preview, but take less time to load and may result in a faster display. The default value of 64 means a circle of up to 3 inches will be displayed to within 1 mil (.03%).

MDI_HISTORY_FILE = - The name of a local MDI history file. If this is not specified Axis will save the MDI history in .axis_mdi_history in the user’s home directory. This is useful if you have multiple configurations on one computer.

JOG_AXES = - The order in which jog keys are assigned to axis letters. The left and right arrows are assigned to the first axis letter, up and down to the second, page up/page down to the third, and left and right bracket to the fourth. If unspecified, the default is determined from the [TRAJ]COORDINATES, [DISPLAY]LATHE and [DISPLAY]FOAM values.

JOG_INVERT = - For each axis letter, the jog direction is inverted. The default is "X" for lathes and blank otherwise.

USER_COMMAND_FILE = mycommands.py — The name of an optional, configuration-specific python file sourced by the axis gui instead of the user-specific file ~/.axisrc.

HELP_FILE = tklinucnc.txt - Path to help file.

PROGRAM_EXTENSION = .extension Description

PROGRAM_EXTENSION = .NGC XYZ Post Processor

PROGRAM_EXTENSION = .png,.gif,.jpg Greyscale Depth Image

PROGRAM_EXTENSION = .gcode 3D Printer

PROGRAM_EXTENSION = .py Python Script

FILTER_PROGRESS=%d

PARAMETER_FILE = myfile.var - The file located in the same directory as the ini file which contains the parameters used by the interpreter (saved between runs).

ORIENT_OFFSET = 0 - A float value added to the R word parameter of an M19 Orient Spindle operation. Used to define an arbitrary zero position regardless of encoder mount orientation.

RS274NGC_STARTUP_CODE = G17 G20 G40 G49 G64 P0.001 G80 G90 G92 G94 G97 G98 - A string of NC codes that the interpreter is initialized with. This is not a substitute for specifying modal g-codes at the top of each ngc file, because the modal codes of machines differ, and may be changed by g-code interpreted earlier in the session.

SUBROUTINE_PATH = ncsubroutines:/tmp/testsubs:lathesubs:millsubs - Specifies a colon (:) separated list of up to 10 directories to be searched when single-file subroutines are specified in gcode. These directories are searched after searching [DISPLAY]PROGRAM_PREFIX (if it is specified) and before searching [WIZARD]WIZARD_ROOT (if specified). The paths are searched in the order that they are listed. The first matching subroutine file found in the search is used. Directories are specified relative to the current directory for the ini file or as absolute paths. The list must contain no intervening whitespace.

CENTER_ARC_RADIUS_TOLERANCE_INCH = n Default 0.00005

CENTER_ARC_RADIUS_TOLERANCE_MM = n Default 0.00127

USER_M_PATH = myfuncs:/tmp/mcodes:experimentalmcodes - Specifies a list of colon (:) separated directories for user defined functions. Directories are specified relative to the current directory for the ini file or as absolute paths. The list must contain no intervening whitespace.

INI_VARS = 1 Default 1 Allows G-code programs to read values from the INI file using the format #<_ini[section]name>. See G-code Parameters.

HAL_PIN_VARS = 1 Default 1 Allows G-code programs to read the values of HAL pins using the format #<_hal[Hal item]>. Variable access is read-only. See G-code Parameters for more details and an important caveat.

RETAIN_G43 = 0 Default 0 When set, you can turn on G43 after loading the first tool, and then not worry about it through the program. When you finally unload the last tool, G43 mode is canceled.

OWORD_NARGS = 0 Default 0 If this feature is enabled then a called subroutine can determine the number of actual positional parameters passed by inspecting the #<n_args> parameter.

NO_DOWNCASE_OWORD = 0 Default 0 Preserve case in O-word names within comments if set, enables reading of mixed-case HAL items in structured comments like (debug, #<_hal[MixedCaseItem]).

OWORD_WARNONLY = 0 Default 0 Warn rather than error in case of errors in O-word subroutines.

REMAP=M400 modalgroup=10 argspec=Pq ngc=myprocedure See Remap Extending G-Code chapter for details.

ON_ABORT_COMMAND=O <on_abort> call See Remap Extending G-Code chapter for details.

EMCMOT = motmod - the motion controller name is typically used here.

BASE_PERIOD = 50000 - the Base task period in nanoseconds.

SERVO_PERIOD = 1000000 - This is the "Servo" task period in nanoseconds.

TRAJ_PERIOD = 100000 - This is the Trajectory Planner task period in nanoseconds.

COMM_TIMEOUT = 1.0 - Number of seconds to wait for Motion (the realtime part of the motion controller) to acknowledge receipt of messages from Task (the non-realtime part of the motion controller).

TASK = milltask - Specifies the name of the task executable. The task executable does various things, such as communicate with the UIs over NML, communicate with the realtime motion planner over non-HAL shared memory, and interpret gcode. Currently there is only one task executable that makes sense for 99.9% of users, milltask.

CYCLE_TIME = 0.010 - The period, in seconds, at which TASK will run. This parameter affects the polling interval when waiting for motion to complete, when executing a pause instruction, and when accepting a command from a user interface. There is usually no need to change this number.

HALFILE = example.hal - Execute the file example.hal at start up. If HALFILE is specified multiple times, the files are executed in the order they appear in the ini file. Almost all configurations will have at least one HALFILE, and stepper systems typically have two such files, one which specifies the generic stepper configuration (core_stepper.hal) and one which specifies the machine pin out (xxx_pinout.hal).

HALFILES are found using a search.  If the named file is found in the directory
containing the ini file, it is used.  If the named file is not found in this
ini file directory, a search is made using a system library of halfiles.

If LinuxCNC is started with the linuxcnc script using the "-H dirname" option,
the specified dirname is prepended to the search described above so that
"dirname" is searched first.  The "-H dirname" option may be specified more
than once, directories are prepended in order.

A HALFILE may also be specified as an absolute path (when the name starts with
a '/' character).  Absolute paths are not recommended as their use may limit
relocation of configurations.

HALFILE = texample.tcl [arg1 [arg2] …]] - Execute the tcl file texample.tcl at start up with arg1, arg2, etc as ::argv list. Files with a .tcl suffix are processed as above but use haltcl for processing See the HALTCL Chapter for more information.

HALFILE = LIB:sys_example.hal - Execute the system library file sys_example.hal at start up. Explicit use of the LIB: prefix causes use of the system library HALFILE without searching the ini file directory.

HALFILE = LIB:sys_texample.tcl [arg1 [arg2 …]] - Execute the system library file sys_texample.tcl at start up. Explicit use of the LIB: prefix causes use of the system library HALFILE without searching the ini file directory.

TWOPASS = ON - Use twopass processing for loading HAL components. With TWOPASS processing, [HAL]HALFILE= lines are processed in two passes. In the first pass (pass0), all HALFILES are read and multiple appearances of loadrt and loadusr commands are accumulated. These accumulated load commands are executed at the end of pass0. This accumulation allows load lines to be specified more than once for a given component (provided the names= names used are unique on each use). In the second pass (pass1), the HALFILES are reread and all commands except the previously executed load commands are executed.

TWOPASS = nodelete verbose - The TWOPASS feature can be activated with any non-null string including the keywords verbose and nodelete. The verbose keyword causes printing of details to stdout. The nodelete keyword preserves temporary files in /tmp.

HALCMD = command - Execute command as a single HAL command. If HALCMD is specified multiple times, the commands are executed in the order they appear in the ini file. HALCMD lines are executed after all HALFILE lines.

SHUTDOWN = shutdown.hal - Execute the file shutdown.hal when LinuxCNC is exiting. Depending on the hardware drivers used, this may make it possible to set outputs to defined values when LinuxCNC is exited normally. However, because there is no guarantee this file will be executed (for instance, in the case of a computer crash) it is not a replacement for a proper physical e-stop chain or other protections against software failure.

POSTGUI_HALFILE = example2.hal - Execute example2.hal after the GUI has created its HAL pins. Some GUIs create hal pins and support the use of a postgui halfile to use them. GUIs that support postgui halfiles include Touchy, Axis, Gscreen, and gmoccapy.

See section <<sec:pyvcp-with-axis,pyVCP with Axis>> Section for more information.

HALUI = halui - adds the HAL user interface pins. For more information see the HAL User Interface chapter.

MDI_COMMAND = G53 G0 X0 Y0 Z0 - An MDI command can be executed by using halui.mdi-command-00. Increment the number for each command listed in the [HALUI] section.

DELAY = value - seconds to wait beore starting other applications. A delay may be needed if an application has dependencies on [HAL]POSTGUI_HALFILE actions or gui-created hal pins (default DELAY=0).

APP = appname [arg1 [arg2 …]] - Application to be started. This specification can be included multiple times. The appname can be explicitly named as an absolute or tilde specified filename (first character is / or ~), a relative filename (first characters of filename are ./), or as a file in the inifile directory. If no executable file is found using these names, then the user search PATH is used to find the application.

Examples:

ARC_BLEND_ENABLE = 1 - Turn on new TP. If set to 0 TP uses parabolic blending (1 segment look ahead.) Default value 1.

ARC_BLEND_FALLBACK_ENABLE = 0 - Optionally fall back to parabolic blends if the estimated speed is faster. However, this estimate is rough, and it seems that just disabling it gives better performance. Default value 0.

ARC_BLEND_OPTIMIZATION_DEPTH = 50 - Look ahead depth in number of segments.

ARC_BLEND_GAP_CYCLES = 4 How short the previous segment must be before the trajectory planner consumes it.

ARC_BLEND_RAMP_FREQ = 20 - This is a cutoff frequency for using ramped velocity.

SPINDLES = 3 - The number of spindles to support. It is imperative that this number matches the "num_spindles" parameter passed to the motion module.

COORDINATES = X Y Z - The names of the axes being controlled. Only X, Y, Z, A, B, C, U, V, W are valid. Only axes named in COORDINATES are accepted in g-code. It is permitted to write an axis name more than once (e.g., X Y Y Z for a gantry machine). For the common trivkins kinematics, joint numbers are assigned in sequence according to the trivkins parameter coordinates=. So, for trivkins coordinates=xz, joint0 corresponds to X and joint1 corresponds to Z. See the kinematics man page ($ man kins) for information on trivkins and other kinematics modules.

LINEAR_UNITS = <units> - Specifies the machine units for linear axes. Possible choices are mm or inch. This does not affect the linear units in NC code (the G20 and G21 words do this).

ANGULAR_UNITS = <units> - Specifies the machine units for rotational axes. Possible choices are deg, degree (360 per circle), rad, radian (2pi per circle), grad, or gon (400 per circle). This does not affect the angular units of NC code. In RS274NGC, A-, B- and C- words are always expressed in degrees.

DEFAULT_LINEAR_VELOCITY = 0.0167 - The initial rate for jogs of linear axes, in machine units per second. The value shown in Axis equals machine units per minute.

DEFAULT_LINEAR_ACCELERATION = 2.0 - In machines with nontrivial kinematics, the acceleration used for "teleop" (Cartesian space) jogs, in machine units per second per second.

MAX_LINEAR_VELOCITY = 5.0 - The maximum velocity for any axis or coordinated move, in machine units per second. The value shown equals 300 units per minute.

MAX_LINEAR_ACCELERATION = 20.0 - The maximum acceleration for any axis or coordinated axis move, in machine units per second per second.

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. This assumes there was no movement of the machine while powered off. If unset, joint positions are not stored and will begin at 0 each time LinuxCNC is started. This can help on smaller machines without home switches. If using the Mesa resolver interface this file can be used to emulate absolute encoders and eliminate the need for homing (with no loss of accuracy). See the hostmot2 manpage for more details.

NO_FORCE_HOMING = 1 - The default behavior is for LinuxCNC to force the user to home the machine before any MDI command or a program is run. Normally, only jogging is allowed before homing. For configurations using identity kinematics, setting NO_FORCE_HOMING = 1 allows the user to make MDI moves and run programs without homing the machine first. Interfaces using identity kinematics without homing ability will need to have this option set to 1.

HOME = 0 0 0 0 0 0 0 0 0 - World home position needed for kinematics modules that compute world coordinates using kinematicsForward() when switching from joint to teleop mode. Up to nine coordinate values (X Y Z A B C U V W) may be specified, unused trailing items may be omitted. This value is only used for machines with nontrivial kinematics. On machines with trivial kinematics (mill, lathe, gantry types) this value is ignored. Note: the sim hexapod config requires a non-zero value for the Z coordinate.

JOINTS = 3 - Specifies the number of joints (motors) in the system. For example, a trivkins XYZ machine with a single motor for each axis has 3 joints. A gantry machine with one motor on each of two of the axes, and two motors on the third axis, has 4 joints. (This config variable may be used by a gui to set the number of joints (num_joints) specified to the motion module (motmod)). The Axis gui, pncconf, and stepconf use this item.

KINEMATICS = trivkins - Specify a kinematics module for the motion module. Guis may use this variable to specify the loadrt line in hal files for the motmod module. For more information on kinematics modules see the manpage: $ man kins

MAX_VELOCITY = 1.2 - Maximum velocity for this axis in machine units per second.

MAX_ACCELERATION = 20.0 - Maximum acceleration for this axis in machine units per second squared.

MIN_LIMIT = -1000 - The minimum limit (soft limit) for axis motion, in machine units. When this limit is exceeded, the controller aborts axis motion. The axis must be homed before MIN_LIMIT is in force. For a rotary axis (A,B,C typ) with unlimited rotation having no MIN_LIMIT for that axis in the [AXIS_<letter>] section a value of -1e99 is used.

MAX_LIMIT = 1000 - The maximum limit (soft limit) for axis motion, in machine units. When this limit is exceeded, the controller aborts axis motion. The axis must be homed before MAX_LIMIT is in force. For a rotary axis (A,B,C typ) with unlimited rotation having no MAX_LIMIT for that axis in the [AXIS_<letter>] section a value of 1e99 is used.

WRAPPED_ROTARY = 1 - When this is set to 1 for an ANGULAR axis the axis will move 0-359.999 degrees. Positive Numbers will move the axis in a positive direction and negative numbers will move the axis in the negative direction.

LOCKING_INDEXER_JOINT = 4 - This value selects a joint to use for a locking indexer for the specified axis <letter>. In this example, the joint is 4 which would correspond to the B axis for a XYZAB system with trivkins (identity) kinematics. When set, a G0 move for this axis will initiate an unlock with the joint.4.unlock pin then wait for the joint.4.is-unlocked pin then move the joint at the rapid rate for that joint. After the move the joint.4.unlock will be false and motion will wait for joint.4.is-unlocked to go false. Moving with other joints is not allowed when moving a locked rotary joint. To create the unlock pins, use the motmod parameter:

unlock_joints_mask=jointmask

The jointmask bits are: (LSB)0:joint0, 1:joint1, 2:joint2, ...

Example: loadrt motmod ... unlock_joints_mask=0x38
creates  unlock  pins for joints 3,4,5

OFFSET_AV_RATIO = 0.1 - If nonzero, this item enables the use of hal input pins for external axis offsets:

'axis.<letter>.eoffset-enable'
'axis.<letter>.eoffset-counts'
'axis.<letter>.eoffset-scale'

JOINT_0 = X

JOINT_1 = Y

JOINT_2 = Z

JOINT_3 = A

JOINT_4 = B

JOINT_5 = C

JOINT_6 = U

JOINT_7 = V

JOINT_8 = W

JOINT_0 = X

JOINT_1 = Z

TYPE = LINEAR - The type of joint, either LINEAR or ANGULAR.

UNITS = INCH - If specified, this setting overrides the related [TRAJ] UNITS setting. (e.g., [TRAJ]LINEAR_UNITS if the TYPE of this joint is LINEAR, [TRAJ]ANGULAR_UNITS if the TYPE of this joint is ANGULAR)

MAX_VELOCITY = 1.2 - Maximum velocity for this joint in machine units per second.

MAX_ACCELERATION = 20.0 - Maximum acceleration for this joint in machine units per second squared.

BACKLASH = 0.0000 - Backlash in machine units. Backlash compensation value can be used to make up for small deficiencies in the hardware used to drive an joint. If backlash is added to an joint and you are using steppers the STEPGEN_MAXACCEL must be increased to 1.5 to 2 times the MAX_ACCELERATION for the joint. Excessive backlash compensation can cause an joint to jerk as it changes direction. If a COMP_FILE is specified for a joint BACKLASH is not used.

COMP_FILE = file.extension - The compensation file consists of map of position information for the joint. Compensation file values are in machine units. Each set of values are are on one line separated by a space. The first value is the nominal value (the commanded position). The second and third values depend on the setting of COMP_FILE_TYPE. Points in between nominal values are interpolated between the two nominals. Compensation files must start with the smallest nominal and be in ascending order to the largest value of nominals. File names are case sensitive and can contain letters and/or numbers. Currently the limit inside LinuxCNC is for 256 triplets per joint.

If COMP_FILE is specified for an joint, BACKLASH is not used. A COMP_FILE_TYPE must be specified for each COMP_FILE.

COMP_FILE_TYPE = 0 or 1 - Specifies the type of compensation file. The first value is the nominal (commanded) position for both types.

MIN_LIMIT = -1000 - The minimum limit for joint motion, in machine units. When this limit is reached, the controller aborts joint motion. For a rotary joint with unlimited rotation having no MIN_LIMIT for that joint in the [JOINT_N] section a the value -1e99 is used.

MAX_LIMIT = 1000 - The maximum limit for joint motion, in machine units. When this limit is reached, the controller aborts joint motion. For a rotary joint with unlimited rotation having no MAX_LIMIT for that joint in the [JOINT_N] section a the value 1e99 is used.

MIN_FERROR = 0.010 - This is the value in machine units by which the joint 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 machine 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 following errors will always be present due to vibration, etc.

LOCKING_INDEXER = 1 - Indicates the joint is used as a locking indexer.

HOME = 0.0 - The position that the joint will go to upon completion of the homing sequence.

HOME_OFFSET = 0.0 - The joint position of the home switch or index pulse, in machine units. When the home point is found during the homing process, this is the position that is assigned to that point. When sharing home and limit switches and using a home sequence that will leave the home/limit switch in the toggled state the home offset can be used define the home switch position to be other than 0 if your HOME position is desired to be 0.

HOME_SEARCH_VEL = 0.0 - Initial homing velocity in machine units per second. Sign denotes direction of travel. 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 at zero.

HOME_LATCH_VEL = 0.0 - Homing velocity in machine units per second to the home switch latch position. Sign denotes direction of travel.

HOME_FINAL_VEL = 0.0 - Velocity in machine units per second from home latch position to home position. If left at 0 or not included in the joint rapid velocity is used. Must be a positive number.

HOME_USE_INDEX = NO - If the encoder used for this joint 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. Currently, you can’t home to index with steppers unless you’re using stepgen in velocity mode and PID.

HOME_INDEX_NO_ENCODER_RESET = NO - Use YES if the encoder used for this joint does not reset its counter when an index pulse is detected after assertion of the joint index_enable hal pin. Applicable only for HOME_USE_INDEX = YES.

HOME_IGNORE_LIMITS = NO - When you use the limit switch as a home switch and the limit switch this should be set to YES. When set to YES the limit switch for this joint is ignored when homing. You must configure your homing so that at the end of your home move the home/limit switch is not in the toggled state you will get a limit switch error after the home move.

HOME_IS_SHARED = <n> - If the home input is shared by more than one joint set <n> to 1 to prevent homing from starting if the one of the shared switches is already closed. Set <n> to 0 to permit homing if a switch is closed.

HOME_ABSOLUTE_ENCODER = 0 | 1 | 2 - Used to indicate the joint uses an absolute encoder. At a request for homing, the current joint value is set to the HOME_OFFSET value. If the HOME_ABSOLUTE_ENCODER setting is 1, the machine makes the usual final move to the HOME value. If the HOME_ABSOLUTE_ENCODER setting is 2, no final move is made.

HOME_SEQUENCE = <n> - Used to define the "Home All" sequence. <n> must start at 0 or 1 or -1. Additional sequences may be specified with numbers increasing by 1 (in absolute value). Skipping of sequence numbers is not allowed. If a HOME_SEQUENCE is omitted, the joint will not be homed by the "Home All" function. More than one joint can be homed at the same time by specifying the same sequence number for more than one joint. A negative sequence number is used to defer the final move for all joints having that (negative or positive) sequence number. For additional info, see: HOME SEQUENCE

VOLATILE_HOME = 0 - When enabled (set to 1) this joint will be unhomed if the Machine Power is off or if E-Stop is on. This is useful if your machine has home switches and does not have position feedback such as a step and direction driven machine.

DEADBAND = 0.000015 - How close is close enough to consider the motor in position, in machine units. This is often set to a distance equivalent to 1, 1.5, 2, or 3 encoder counts, but there are no strict rules. Looser (larger) settings allow less servo hunting at the expense of lower accuracy. Tighter (smaller) settings attempt higher accuracy at the expense of more servo hunting. Is it really more accurate if it’s also more uncertain? As a general rule, it’s good to avoid, or at least limit, servo hunting if you can.

BIAS = 0.000 - This is used by hm2-servo and some others. Bias is a constant amount that is added to the output. In most cases it should be left at zero. However, it can sometimes be useful to compensate for offsets in servo amplifiers, or to balance the weight of an object that moves vertically. bias is turned off when the PID loop is disabled, just like all other components of the output.

P = 50 - The proportional gain for the joint servo. This value multiplies the error between commanded and actual position in machine units, resulting in a contribution to the computed voltage for the motor amplifier. The units on the P gain are volts per machine unit, e.g.,

I = 0 - The integral gain for the joint servo. The value multiplies the cumulative error between commanded and actual position in machine units, resulting in a contribution to the computed voltage for the motor amplifier. The units on the I gain are volts per machine unit second, e.g.,

D = 0 - The derivative gain for the joint 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 machine unit per second, e.g.,

FF0 = 0 - The 0th order feed forward 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 FF0 gain are volts per machine unit, e.g.,

FF1 = 0 - The 1st order feed forward 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 machine unit per second, e.g.,

FF2 = 0 - The 2nd order feed forward 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 FF2 gain are volts per machine unit per second per second, e.g.,

OUTPUT_SCALE = 1.000 -

OUTPUT_OFFSET = 0.000 - These two values are the scale and offset factors for the joint 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 LinuxCNC first converts the desired output in quasi-SI units to raw actuator values, e.g., volts for an amplifier DAC. This scaling looks like:

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. The value is applied symmetrically to both the plus and the minus side.

INPUT_SCALE = 20000 - in Sample configs

ENCODER_SCALE = 20000 - in PNCconf built configs Specifies the number of pulses that corresponds to a move of one machine unit as set in the [TRAJ] section. For a linear joint one machine unit will be equal to the setting of LINEAR_UNITS. For an angular joint one unit is equal to the setting in ANGULAR_UNITS. A second number, if specified, is ignored. For example, on a 2000 counts per rev encoder, and 10 revs/inch gearing, and desired units of inch, we have:

SCALE = 4000 - in Sample configs

STEP_SCALE = 4000 - in PNCconf built configs Specifies the number of pulses that corresponds to a move of one machine unit as set in the [TRAJ] section. For stepper systems, this is the number of step pulses issued per machine unit. For a linear joint one machine unit will be equal to the setting of LINEAR_UNITS. For an angular joint one unit is equal to the setting in ANGULAR_UNITS. For servo systems, this is the number of feedback pulses per machine unit. A second number, if specified, is ignored.

ENCODER_SCALE = 20000 (Optionally used in PNCconf built configs) - Specifies the number of pulses that corresponds to a move of one machine unit as set in the [TRAJ] section. For a linear joint one machine unit will be equal to the setting of LINEAR_UNITS. For an angular joint one unit is equal to the setting in ANGULAR_UNITS. A second number, if specified, is ignored. For example, on a 2000 counts per rev encoder, and 10 revs/inch gearing, and desired units of inch, we have:

STEPGEN_MAXACCEL = 21.0 - Acceleration limit for the step generator. This should be 1% to 10% larger than the joint MAX_ACCELERATION. This value improves the tuning of stepgen’s "position loop". If you have added backlash compensation to an joint then this should be 1.5 to 2 times greater than MAX_ACCELERATION.

STEPGEN_MAXVEL = 1.4 - Older configuration files have a velocity limit for the step generator as well. If specified, it should also be 1% to 10% larger than the joint MAX_VELOCITY. Subsequent testing has shown that use of STEPGEN_MAXVEL does not improve the tuning of stepgen’s position loop.

MAX_VELOCITY = 20000 The maximum spindle speed (in rpm) for the specified spindle. Optional.

MIN_VELOCITY = 3000 The minimum spindle speed (in rpm) for the specified spindle. Optional. Many spindles have a minimum speed below which they should not be run. Any spindle speed command below this limit will be /increased/ to this limit.

MAX_REVERSE_VELOCITY = 20000 This setting will default to MAX_VELOCITY if omitted. It can be used in cases where the spindle speed is limited in reverse. Set to zero for spindles which must not be run in reverse. In this context "max" refers to the absolute magnitude of the spindle speed.

MIN_REVERSE_VELOCITY = 3000 This setting is equivalent to MIN_VELOCITY but for reverse spindle rotation. It will default to the MIN_VELOCITY if omitted.

INCREMENT = 200 Sets the step size for spindle speed increment / decrement commands. This can have a different value for each spindle. This setting is effective with Axis and Touchy but note that some GUIs may handle things differently.

HOME_SEARCH_VELOCITY = 100 - FIXME: Spindle homing not yet working Sets the homing speed (rpm) for the spindle. The spindle will rotate at this velocity during the homing sequence until the spindle index is located, at which point the spindle position will be set to zero. Note that it makes no sense for the spindle home position to be any value other than zero, and so there is no provision to do so.

HOME_SEQUENCE = 0 - FIXME: Spindle homing not yet working Controls where in the general homing sequence the spindle homing rotations occur. Set the HOME_SEARCH_VELOCITY to zero to avoid spindle rotation during the homing sequence

EMCIO = io - Name of IO controller program

CYCLE_TIME = 0.100 - The period, in seconds, at which EMCIO will run. Making it 0.0 or a negative number will tell EMCIO not to sleep at all. There is usually no need to change this number.

TOOL_TABLE = tool.tbl - The file which contains tool information, described in the User Manual.

DB_PROGRAM = db_program - Path to an executable program that manages tool data. (When a DB_PROGRAM is specified, a TOOL_TABLE entry is ignored)

TOOL_CHANGE_POSITION = 0 0 2 - Specifies the XYZ location to move to when performing a tool change if three digits are used. Specifies the XYZABC location when 6 digits are used. Specifies the XYZABCUVW location when 9 digits are used. Tool Changes can be combined. For example if you combine the quill up with change position you can move the Z first then the X and Y.

TOOL_CHANGE_WITH_SPINDLE_ON = 1 - The spindle will be left on during the tool change when the value is 1. Useful for lathes or machines where the material is in the spindle, not the tool.

TOOL_CHANGE_QUILL_UP = 1 - The Z axis will be moved to machine zero prior to the tool change when the value is 1. This is the same as issuing a G0 G53 Z0.

TOOL_CHANGE_AT_G30 = 1 - The machine is moved to reference point defined by parameters 5181-5186 for G30 if the value is 1. For more information see G-Code Parameters and G-Code G30-G30.1.

RANDOM_TOOLCHANGER = 1 - This is for machines that cannot place the tool back into the pocket it came from. For example, machines that exchange the tool in the active pocket with the tool in the spindle.