Thanks for your comments Andy but I can't see anything wrong in my ini file and still can't understand what is going on. The problem I was describing of not being able to reliably set zero home positions occurs when I first switch the machines on. For instance, I just turned on to set up a new job and the readings on the axes display in AXIS were - X 0.000, Y -0.000, Z -10.418 and A 737.592 I then issued a G92 X0.000 Y0.000 Z0.000 A0.000 in the MDI and all the axis readings then went to 0.000 - good. Then I hit the home button on each axis and they all showed the home icon with the displayed figures staying at 0.000 Now I jogged to X 2.752 Y 2.279 Z2.208 A -10.131 and then tried to 'touch off' each axis, setting each one to 0.000 in the touch off box. The readings then immediately went to X 12.842 Y -5.931 Z 4.645 A -56.156 ! The figures for the X and Y axis I can partly understand in that they were the positions I jogged to on a previous job but why the machine remembered them and went to them rather than the 0.000 I commanded I don't know. The figures for the Z and A axes are a total mystery and mean nothing to me at all. I have found that if I repeat the G92, home, then touch off about 3 times, the axes figures will settle at 0.000 after touching off but I don't know why.. The only EMC file I altered is the ini file which is listed below and seems innocuous to me. Can anyone offer any enlightenment please??
# EMC controller parameters for generic controller. Make these what you need # for your system. # General note: Comments can either be preceded with a # or ; - either is # acceptable, although # is in keeping with most linux config files. # Settings with a + at the front of the comment are likely needed to get # changed by the user. # Settings with a - at the front are highly unneeded to be changed ############################################################################### # General section ############################################################################### [EMC] #- Version of this INI file VERSION = $Revision: 1.7.2.3 $ #+ Name of machine, for use with display, etc. MACHINE = EMC-HAL-STEP-XYZA-MM #- Name of NML file to use, default is configs/common/emc.nml NML_FILE = emc.nml #+ Debug level, 0 means no messages. See src/emc/nml_int/emcglb.h for others DEBUG = 0 # DEBUG = 0x00000007 # DEBUG = 0x7FFFFFFF ############################################################################### # Sections for display options ############################################################################### [DISPLAY] #+ Name of display program, e.g., xemc DISPLAY = axis # DISPLAY = usrmot # DISPLAY = mini # DISPLAY = tkemc # Cycle time, in seconds, that display will sleep between polls CYCLE_TIME = 0.100 #- Path to help file HELP_FILE = doc/help.txt #- Initial display setting for position, RELATIVE or MACHINE POSITION_OFFSET = RELATIVE #- Initial display setting for position, COMMANDED or ACTUAL POSITION_FEEDBACK = ACTUAL #+ Highest value that will be allowed for feed override, 1.0 = 100% MAX_FEED_OVERRIDE = 9.0 #- Prefix to be used PROGRAM_PREFIX = /home/ian/emc2/nc_files #- Introductory graphic INTRO_GRAPHIC = emc2.gif INTRO_TIME = 3 ############################################################################### # Task controller section ############################################################################### [TASK] #- Name of task controller program, e.g., bridgeporttask TASK = milltask # TASK = minimilltask #- Cycle time, in seconds, that task controller will sleep between polls CYCLE_TIME = 0.007 ############################################################################### # Part program interpreter section ############################################################################### [RS274NGC] #- File containing interpreter variables PARAMETER_FILE = stepper.var ############################################################################### # Motion control section ############################################################################### [EMCMOT] #- Name of the motion controller to use (only one exists for nontrivkins) EMCMOT = motmod #- Key for real OS shared memory, e.g., for simulated motion SHMEM_KEY = 111 #- Timeout for comm to emcmot, in seconds COMM_TIMEOUT = 1.0 #- Interval between tries to emcmot, in seconds COMM_WAIT = 0.010 #+ Base task period, in nanosecs - this is the fastest thread in the machine BASE_PERIOD = 40000 #- Servo task period, in nanosecs - will be rounded to an int multiple of BASE_PERIOD SERVO_PERIOD = 1000000 #- Trajectory Planner task period, in nanosecs - will be rounded to an # integer multiple of SERVO_PERIOD TRAJ_PERIOD = 5000000 ############################################################################### # Hardware Abstraction Layer section ############################################################################### [HAL] # The run script first uses halcmd to execute any HALFILE # files, and then to execute any individual HALCMD commands. # # list of hal config files to run through halcmd #+ files are executed in the order in which they appear HALFILE = stepper_xyza.hal #HALFILE = xylotex_pinout.hal HALFILE = standard_pinout.hal #- list of halcmd commands to execute # commands are executed in the order in which they appear #HALCMD = save neta ############################################################################### # Trajectory planner section ############################################################################### [TRAJ] #+ machine specific settings STEPGEN_MAXACCEL = 396.0 AXES = 4 # COORDINATES = X Y Z R P W COORDINATES = X Y Z A HOME = 0 0 0 0 LINEAR_UNITS = metric ANGULAR_UNITS = degree CYCLE_TIME = 0.007 DEFAULT_VELOCITY = 3 DEFAULT_ANGULAR_VELOCITY = 20 MAX_VELOCITY = 5 MAX_ANGULAR_VELOCITY = 20.5 DEFAULT_ACCELERATION = 3 MAX_ACCELERATION = 4 ############################################################################### # Axes sections ############################################################################### #+ First axis [AXIS_0] TYPE = LINEAR HOME = 0 MAX_VELOCITY = 5 # NOTE: the step generator module 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_MAXACCEL below to a few percent # higher than the regular acceleration limit MAX_ACCELERATION = 3 STEPGEN_MAXVEL = 10 STEPGEN_MAXACCEL = 5 BACKLASH = 0.000 INPUT_SCALE = 400 OUTPUT_SCALE = 1.000 MIN_LIMIT = -200.00 MAX_LIMIT = 120.0 FERROR = 0.80 MIN_FERROR = 0.10 HOME_OFFSET = 0 HOME_SEARCH_VEL = 0 HOME_LATCH_VEL = 0 HOME_USE_INDEX = NO HOME_IGNORE_LIMITS = NO #+ Second axis [AXIS_1] TYPE = LINEAR HOME = 0.000 MAX_VELOCITY = 2.5 MAX_ACCELERATION = 2 STEPGEN_MAXVEL = 3.20 STEPGEN_MAXACCEL = 2 BACKLASH = 0.000 INPUT_SCALE = -400 OUTPUT_SCALE = 1.000 MIN_LIMIT = -20.0 MAX_LIMIT = 90.0 FERROR = 1 MIN_FERROR = 0.2 HOME_OFFSET = 0.0 HOME_SEARCH_VEL = 0 HOME_LATCH_VEL = 0 HOME_USE_INDEX = NO HOME_IGNORE_LIMITS = NO #+ Third axis [AXIS_2] TYPE = LINEAR HOME = 0 MAX_VELOCITY = 3 MAX_ACCELERATION = 2 STEPGEN_MAXVEL = 5 STEPGEN_MAXACCEL = 5 BACKLASH = 0.000 INPUT_SCALE = -400 OUTPUT_SCALE = 1.000 MIN_LIMIT = -90.0 MAX_LIMIT = 90.0 FERROR = 0.700 MIN_FERROR = 0.20 HOME_OFFSET = 0.0 HOME_SEARCH_VEL = 0 HOME_LATCH_VEL = 0 HOME_USE_INDEX = NO HOME_IGNORE_LIMITS = NO #+ Fourth axis [AXIS_3] TYPE = ANGULAR HOME = 0.0 MAX_VELOCITY = 8.0 MAX_ACCELERATION = 8.0 STEPGEN_MAXVEL = 20.5 STEPGEN_MAXACCEL = 39.0 BACKLASH = 0.000 INPUT_SCALE = 50 OUTPUT_SCALE = 1.000 MIN_LIMIT = -360000.0 MAX_LIMIT = 360000.0 FERROR = 5.0 MIN_FERROR = 1.0 HOME_OFFSET = 0.0 HOME_SEARCH_VEL = 0.0 HOME_LATCH_VEL = 0.0 HOME_USE_INDEX = NO HOME_IGNORE_LIMITS = NO ############################################################################### # section for main IO controller parameters ############################################################################### [EMCIO] #- Name of IO controller program, e.g., io EMCIO = io #- cycle time, in seconds CYCLE_TIME = 0.080 #- tool table file TOOL_TABLE = stepper.tbl -- Best wishes, Ian ____________ Ian W. Wright Sheffield UK "The difference between theory and practice is much smaller in theory than in practice..." ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
