New to G68

[stevenprofke]

Hi,
I'm a newbie at using G68, so having some issues.
i have a square casting that has a round boss on the bottom, i have to hold the round boss and machine the square.
i want to use G68 to make sure I'm machining square but also need to set the G54 in the middle of the square casting not of the round boss.
i have written what i thought would work but I'm having issues with where the controller stores the macro angular change.
I have tried using a G54 for the datum and G55 for just the angle but they store in the same place and keep over writing.
%
O0
(SQUARE PILOT)
(T25|6MM PROBE|H25)
(T6|10 MAPAL|H6)
(T10|16. AZSTAR BALL ENDMILL|H10)
G21
G00 G17 G40 G49 G80 G90
(PROBE)
T25 M06
(move from centre)
G00 G90 G54 X-46. Y-46.
G43 H25 Z20.
Z10.
G01 Z5. F1000.
G01 Z-20. F1000.
(corner probe)
G00 G90
G65 P9023 A15. I50. J50. B1. S54.
G00 Z50.
G91 G28 Z0.
G00 G90 G54 X37.5 Y37.5
G43 H25 Z20.
G00 Z10.
G01 Z5. F1000.
(centre probe)
G00 G90
G65 P9023 A16. X75. Y75. Z-20. S54.
G00 Z50.
M05
G91 G28 Z0.
M01
G21
G0 G17 G40 G49 G80 G90
(10mm MAPAL VH)
T6 M6
G0 G90 G54 X-39.105 Y-45.617 S4800 M3
G43 H6 Z50. T10
M8
(READ G68 R#189)
G68 X0 Y0 R#189
Z5.
G1 Z-7. F1000.
X-40.214 Y-42.636 F1100.

[steve pies]

im not the best at reading other peoples programs but when i used to do this i would always store the value #189 in a second variable #800. this program is for an edge location on G54 not a center xoyo but it might show what i mean.

G00 G17 G40 G49 G69 G80 G90
T1 M06
( T1 | PROBE | H1 )
( LOCATE PARTS )
G00 G90 G54 X0. Y0.3
G43 H01 Z3.
G01 Z0.2 F50.
G00 G90
G01 Z-0.15 F50.
G65 P9023 A8. S54.
G65 P9832
G65 P9810 Z-0.1 F50.
G65 P9843 Y0. D10.
G65 P9810 Z0.2 F100.
G65 P9833
#800= #189
Z0.2
G00 G53 Z0.
G53 X-29. Y0.
M01
T3 M06
( T3 | 1" X .39 ROUGHDRUM | H3 | D3 )
( ROUGH FRONT SIDE AT 6.370 )
G68 G54 X0. Y0. R#800
G00 G90 G54 X6.9 Y-6.95 S9500 M03
G43 H03 Z1.
/ M08
G04 P3.
Z0.1
G01 Z-0.22 F100.
G41 D03 Y-6.355 F5.
X-6.6
G40 Y-6.88
G00 Z1.
M05
G69
G00 G53 Z0. M09
G53 X-29. Y0.
M01