(author: Chris P)
(version: 0.4)
(date: 04/25/19)

(Probe front top side for y,z 0,0 position)
(Start probe position is over front edge of stock)
(inside the step off width distance and within max z distance)
(ensure all settings have been set properly according to help diagrams)

o<probe_front_outside> sub

  (uses NGCGUI style arg spec)
  (number after "=" in comment is default value)
  #<probe_tool_number> = #1    (=99)
  #<max_z_distance> = #2       (=0.5000)
  #<max_xy_distance> = #3      (=0.5000)
  #<xy_clearance> = #4         (=0.1000)
  #<z_clearance> = #5          (=0.1000)
  #<step_off_width> = #6       (=0.5000)
  #<extra_probe_depth> = #7    (=0.0000)
  #<probe_slow_fr> = #8        (=0.0)
  #<probe_fast_fr> = #9        (=10.0)
  #<calibration_offset> = #10  (=0.0000)
  #<x_hint> = #11              (=1.0000)
  #<y_hint> = #12              (=1.0000)
  #<diameter_hint> = #13       (=1.0000)
  #<edge_width> = #14          (=0.5000)
  #<probe_mode> = #15          (=0)

  (Cancel G92 offsets)
  G92.1

  #<workspace_y> = #[5202 + [20 * #5220]]

    (Probe Tool Safety Check)
  o<110> if [#5400 NE #<probe_tool_number>]
  (MSG, Specified probe tool #<probe_tool_number> not in spindle, aborting)
   o<Probe_front_outside> return
  o<110> endif

  (Probe Diameter)
  #<probe_diameter> = #5410

  (Probing depth from the z probed clearance height, used for z moves)
  #<z_probe_stack> = [#<z_clearance> + #<probe_diameter> + #<extra_probe_depth>]

  (Probe Y Positioning Move, Step Off Width)
  G91
  G0 Y-[#<step_off_width>]

  (Probe Y Positioning Move, to Probing Depth)
  F[#<probe_fast_fr>]
  G1 Z-[#<z_probe_stack>]

  (Call sub "probe_y_plus" to Probe y+ side of Workpiece)
  o<probe_y_plus> call [#1][#3][#4][#8][#9][#10]

  #<y_plus_zero_edge> = #<_value>

  (value returned safety check, aborts if no value returned)
  o<120> if [#<probe_mode> EQ 1 AND #<_value_returned> NE 1]
    (MSG, Missing Y Sub returned edge parameter, aborting)
    o<probe_front_outside> return
  o<120> endif

  (Probe Completion Move to Z Clearance Plane, and Y Zero)
  G91
  G0 Z[#<z_probe_stack>]
  G90
  G0 Y[#<y_plus_zero_edge>]

  (probe mode rules for WCO or probe position measuring only)
  o<130> if [#<probe_mode> EQ 0]
    (Record Zero in selected axes and WCO)
    G10 L2 P#5220 Y[#<y_plus_zero_edge> + #<workspace_y>]
    o<probe_front_outside> return
  o<130> endif

o<probe_front_outside> endsub

M2 (end program)