O<tool-change> SUB
( see: http://www.linuxcnc.org/index.php/english/forum/10-advanced-configuration/5596-manual-tool-change--tool-lengh-touch-off?start=30#48235 )

( Filename: tool-change.ngc )
( LinuxCNC Manual Tool-Change Subroutines for Milling Machines version 1.1: subroutine 1/2 )
( BEFORE USING CHANGE "CONFIGURATION PARAMETERS" BELOW FOR YOUR MACHINE! )
(  )

( In the LinuxCNC .ini config file, under the [RS274NGC] section add: )
(    # change/add/use SUBROUTINE_PATH to point to the location where these tool-change subroutines are located: )
(    SUBROUTINE_PATH = macros )
(    REMAP=M6    modalgroup=6 ngc=tool-change )
(    REMAP=M600  modalgroup=6 ngc=tool-job-begin )

( and under the [EMCIO] section add: )
(    TOOL_CHANGE_AT_G30 = 0 )

( and ensure neither TOOL_CHANGE_POSITION nor TOOL_CHANGE_QUILL_UP is set. )
(  )

( In the LinuxCNC .hal config file, map some input pin to be the probe input, e.g.: )
(    net probe-z parport.0.pin-12-in => motion.probe-input )
( For multiple probe inputs, the following can be used, in this case a MESA 7i96 is controlling a NO probe, and a NC Toolsetter )
( net probe-in <= hm2_7i96.0.gpio.005.in )
( net length-in <= hm2_7i96.0.gpio.009.in_not )
( net probe-in => or2.0.in0 )
( net length-in => or2.0.in1 )
( net probe-or-length <= or2.0.out => motion.probe-input )
( The following tool change pins are required as well; )
( loadusr -W hal_manualtoolchange )
( net tool-change iocontrol.0.tool-change => hal_manualtoolchange.change )
( net tool-changed iocontrol.0.tool-changed <= hal_manualtoolchange.changed )
( net tool-number iocontrol.0.tool-prep-number => hal_manualtoolchange.number )
( net tool-prepare-loopback iocontrol.0.tool-prepare => iocontrol.0.tool-prepared )

( In your Linuxcnc.var file, ensure you have the following variables #5061, #5062, #5063 )
( They can be manually added and assigned a 0.000 to start )

( In addition I have had to modify the post-processor for the following; )
( Eliminate G43 call outs after tool changes )
( Use G53 instead of G28, typically just a check box when post processing )
( Set machine home for Z in F360 machine setup to be -.250, my machine Zero is at top of travel )

( Usage: M6 in the g-code will invoke a manual tool change with automatic tool height adjustment. )
(        M600 is used at the beginning of the first g-code file of a job so that the next M6 will measure the tool for reference )
(             instead of caluculating a tool length offset. It can also be invoked manually through the MDI before a job starts. )

( My sequence of Running; )
( 1. Use a T99, a .250" Rod, to touch off X, Y, and Z of WCS as modeled in CAM )
( 2. Manually input M600 )
( 3. Manually call an M6 T99, tool will touch off on toolsetter and store tool height )
( 4. Load program and run, M6 in program will prompt tool change, after changing, tool will touch off and Z will adjust )
( 5. Run any and all code using the same desired Z height for the WCS as designed )
( 6. For new WCS repeat from Step #1 )
(  )

( General theory of operation: touches each tool off to the tool height sensor. The first tool is used as the reference, all   )
(     subsequent tools adjust the tool offset.                                                                                 )
(     It is moved away by raising Z to _TravelZ before moving towards the switch, and when                                     )
(     moving back from the switch again moves at height _TravelZ before going straight back down to the original position. Set )
(     all necessary modes to ensure correct operation no matter what state the program is in when this is called. We eliminate )
(     almost all side effects by saving and restoring the modal state. )
(  )

( Side effects: sets G30, sets motion mode to G1. )

(------------------------------- CONFIGURATION PARAMETERS ----------------------------------------------)
#<_UseInches> =         1.0     ( set to 1 to use inches here, or 0 to use millimeters; should match units on tool.tbl dimensions )
#<_TravelZ> =           -.005     ( machine Z coordinate for travelling, typically near max Z to avoid ever hitting the work )
#<_TravelFeed> =      50.0     ( feedrate used for general Z moves when avoiding G0 )
#<_ProbeX> =           1.1     ( machine X coordinate of switch/touch-off plate )
#<_ProbeY> =           0	( machine Y coordinate of switch/touch-off plate )
#<_ProbeFastZ> =       -.005 ( machine Z coord to move to before starting probe, longest tool should not touch switch at this Z )
#<_ProbeMinZ> =        -4.75     ( machine Z coord to stop probe, shortest tool must touch switch at this Z, must be > min Z )
#<_ProbeRetract> =      0.125     ( small distance to retract before approaching switch/touch-off plate second time )
#<_ProbeFastFeed> =   50.0     ( feed rate for moving to _ProbeFastZ )
#<_ProbeFeed1> =       20.0     ( feed rate for touching switch/touch-off plate first time )
#<_ProbeFeed2> =        4.0     ( feed rate for touching switch/touch-off plate second time )
#<_ToolChangeX> =       1.1     ( machine X coordinate to pause at for manual tool changing )
#<_ToolChangeY> =       0	( machine Y coordinate to pause at for manual tool changing )
#<_MistOnDuringProbe> =   0     ( set to 1 for mist, or 2 for coolant, or 0 for nothing during probing, to clear switch of swarf )
(-------------------------------------------------------------------------------------------------------)

O100 IF [ EXISTS[#<_ToolDidFirst>] EQ 0 ]
        #<_ToolDidFirst> = 0                   
	      #<_ToolZRef> = 0                       ( Following were added to clear the memory as residual parameters )
	      #<_ToolZ> = 0                          ( created incorrect settings )
	      #<ToolZLast> = 0
O100 ENDIF
O105 IF [ #<_ToolDidFirst> EQ 0 ]
   G49                                         ( clear tool length compensation prior to saving state if this is first time )
        #<_ToolZRef> = 0                       ( Ensures values are cleared if M600 is not called ) 
        #<_ToolZ> = 0
        #<ToolZLast> = 0

O105 ENDIF

G53 G1 F[#<_TravelFeed>] Z[#<_TravelZ>]
G53 G1 F[#<_TravelFeed>] X[#<_ToolChangeX>] Y[#<_ToolChangeY>]  ( Moves to desired potion for manual tool change )

M6                                             ( do the normal M6 stuff )
M70                                            ( save current modal state )

M9                                             ( turn off coolant, will be restored on return if it was on )
M5                                             ( turn off spindle, cannot be on during the probe )
G[21 - #<_UseInches>]                          ( use inches or millimeters as required here, units will be restored on return )
G30.1                                          ( save current position in #5181-#5183... )
G49                                            ( clear tool length compensation )
G90                                            ( use absolute positioning here )
G94                                            ( use feedrate in units/min )
G40                                            ( turn cutter radius compensation off here )

O200 IF [ #<_ToolDidFirst> EQ 0 ]
  G53 G1 F[#<_TravelFeed>] Z[#<_TravelZ>]      ( go to high travel level on Z )
  G53 G0 X[#<_ProbeX>] Y[#<_ProbeY>]           ( to probe switch )
  G53 G1 F[#<_ProbeFastFeed>] Z[#<_ProbeFastZ>]( move tool closer to switch -- we shouldn't hit it )
  G54 G1 F[#<_ProbeFeed1>] G91                 ( use relative positioning )
  O101 IF [ #<_MistOnDuringProbe> EQ 1 OR #<_MistOnDuringProbe> EQ 2 ]
    M[7 + #<_MistOnDuringProbe> - 1]           ( turn on mist/coolant )
  O101 ENDIF
  G38.2 Z[#<_ProbeMinZ> - #<_ProbeFastZ>] F[#<_ProbeFeed1>]    ( trip switch slowly )
  G0 Z[#<_ProbeRetract>]                       ( go up slightly )
  G38.2 Z[#<_ProbeRetract>*-1.25] F[#<_ProbeFeed2>]   ( trip switch very slowly )
  M9                                           ( turn off mist )
  G90                                          ( use absolute positioning )
  #<_ToolZRef> = #5063                         ( save trip point )
  #<_ToolZLast> = #<_ToolZRef>                 ( save last tool Z position )
  G53 G1 F[#<_TravelFeed>] Z[#<_TravelZ>]      ( return to safe level )
  G53 G0 X[#5181] Y[#5182]                     ( return to where we were in X Y)
  G53 G1 F[#<_TravelFeed>] Z[#5183]            ( return to where we were in Z )
  M72                                          ( restore modal state )
  #<_ToolDidFirst> = 1                         ( we have been in this section to set reference value already )
O200 ELSE
  G53 G1 F[#<_TravelFeed>] Z[#<_TravelZ>]      ( go to high travel level on Z )
  O107 IF [#<_UseInches> EQ 1 ]
    #<ToolDiamIn> = #5410
    #<ToolDiamMM> = [ #<ToolDiamIn> * 25.4 ]
  O107 ELSE
    #<ToolDiamMM> = #5410
    #<ToolDiamIn> = [ #<ToolDiamMM> / 25.4 ]
  O107 ENDIF
  O102 IF [ #<_current_tool> EQ 0 AND #<ToolDiamIn> EQ 0 ]
    (MSG, Change tool then click Resume )
  O102 ELSE
    #<ToolDiamMM> = [ #<ToolDiamIn> * 25.4 ]
  O102 ENDIF
  (M0)                                           ( pause execution )
 
  G53 G0 X[#<_ProbeX>] Y[#<_ProbeY>]           ( to high place directly over switch )
  G53 G1 F[#<_ProbeFastFeed>] Z[#<_ProbeFastZ>]( move tool closer to switch -- we shouldn't hit it )
  G54 G1 F[#<_ProbeFeed1>] G91                 ( use relative positioning )
  O103 IF [ #<_MistOnDuringProbe> EQ 1 OR #<_MistOnDuringProbe> EQ 2 ]
    M[7 + #<_MistOnDuringProbe> - 1]           ( turn on mist/coolant )
  O103 ENDIF
  G38.2 Z[#<_ProbeMinZ> - #<_ProbeFastZ>] F[#<_ProbeFeed1>]     ( trip switch slowly )
  G0 Z[#<_ProbeRetract>]                       ( go up slightly )
  G38.2 Z[#<_ProbeRetract>*-1.25] F[#<_ProbeFeed2>]   ( trip switch very slowly )
  M9                                           ( turn off mist )
  G90                                          ( use absolute positioning )
  #<_ToolZ> = #5063                            ( save new tool length )
  G43.1 Z[#<_ToolZ> - #<_ToolZRef>]            ( set new tool length Z offset, we do this now to show operator even though it has to be set again after M72 )
  G53 G1 F[#<_TravelFeed>] Z[#<_TravelZ>]      ( return to high travel level )
  G53 G0 X[#5181] Y[#5182]                     ( return to where we were in X Y)
  #<_ToolZLast> = #<_ToolZ>                    ( save last tool length )
  
  M72                                          ( restore modal state )
  G43.1 Z[#<_ToolZ> - #<_ToolZRef>]            ( Apply offset to Z height after Modal reset )
  
O200 ENDIF

O<tool-change> ENDSUB
M2