Siemens SINUMERIK 840Di Function Manual page 388

Detailed Description
2.2 Metric/inch measuring system
Examples:
If MD10240 $MN_SCALING_SYSTEM_IS_METRIC=1,
both part programs are executed with a metric setting.
N100 R1=0 R2=0
N120 G01 G70 X1 F1000
N130 $MA_LUBRICATION_DIST[X]=10
N140 NEWCONF
N150 IF ($AA_IW[X]>$MA_LUBRICATION_DIST[X])
N160 R1=1
N170 ENDIF
N180 IF ($AA_IW[X]>10)
N190 R2=1
N200 ENDIF
N210 IF ( (R1<>0) OR (R2<>0))
N220 SETAL(61000)
N230 ENDIF
N240 M30
Note
Alarm 61000 is not output if G70 is replaced by G700 in block N120.
Synchronized actions
In order to prevent the current parts program context from changing the positioning behavior
of a synchronized action arbitrarily in response to asynchronous trigger conditions, the
measuring system must be defined at the time of interpretation. This is the only way to
achieve a defined and reproducible positioning behavior of a synchronized action.
Example 1:
N100 R1=0
N110 G0 X0 Z0
N120 WAITP(X)
N130 ID=1 WHENEVER $R1==1 DO POS[X]=10
N140 R1=1
N150 G71 Z10 F10
N160 G70 Z10 F10
N170 G71 Z10 F10
N180 M30
2-14
;Z=10 mm X=10 mm
;Z=254 mm X=254 mm
;Z=10 mm X=10 mm
Velocities, Setpoint/Actual-Value Systems, Closed-Loop Control (G2)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0