This command stops the program if optional stop is turned on. Pressing cycle start will resume the program. You can press CTRL + O when on the F2-Program & MDI screen page to toggle between Optional Stop ON/OFF and the status is displayed on the bottom status bar.
N10 G00 X0 Y0N20 G00 X10N30 M01N40 G00 Y10
The first line will move both X and Y axis to 0.00 position.
In line two the X axis will move to X 10 position.
In line three the program will stop and wait for user to press cycle start is optional stop is set to On, else will run line four and move Y axis to 10.