Skipping program sequences

In the NC program the command #OPTIONAL EXECUTION can label a sequence of NC blocks as not executable in forward/backward motion on path. The labelled area is then omitted at interpolator level if forward/backward motion is active. However, transition conditions between blocks before and after the omitted area are not recalculated.

#OPTIONAL EXECUTION ON | OFF                                                                                 (modal)

The interpolator context, especially referring to axis positions, must remain unchanged in order to avoid a discontinuous transition of path, velocity and acceleration between these blocks.

Programing Example


Skipping program sequences

X10 Y0

N10 G91 G00 X10 F1000


N12 Z123

N13 S1000 M3

N14 Z-123

N15 M101


N20 G90 G01 X0

N30 G02 I10

N40 G03 J10


The CNC checks and monitors only the continuous position path of axes with or without block skipping. The user must ensure that all other conditions are maintained since the CNC does not check these conditions.

Nesting skipped areas is not considered.

If execution is within an OPTIONAL EXECUTION area and a forward/backward motion is selected, skipping is delayed until #OPTIONAL EXECUTION OFF is reached. This is necessary because only complete areas may be omitted.

Before leaving (M17, M29) the program level where the OPTIONAL EXECUTION was selected (ON), it must also be deselected (OFF). This also applies to leaving the main program level (M30].