Fanuc G81 drilling cycle program with operation repeats

why we can do operation repeat ?

                                            Friends , following fig. program ; we used K4 command in N60 . The reason is , we can see in the following fig. there is 4 hole drilling on similar distance on X30 and Y0 . Therefore we do not have to need specify every time XY  place . In these program in N60 only we used G91 and K4 command .

G76 X_ Y_ Z_ R_ F_ K_ ;
                    Where , XY- Position of hole
                                  Z-  Depth of operation performe
                                  R-  R plane position.
                                  F- cutting feed rate 
                                  K- no of times operation repeats.

O5124

N10   M06 T06 ;

N20   G90 G80 G17 G00 G54 X0 Y0 ;

N30   G43 Z100 H4 ;

N40   M03 S1500 ;

N50   M07 ;

N60   G99  G81 G91 X30 Y0 Z-45 R5  K4 F120  ;  

N70   G98 G90 G80 G00 Z100 ;

N80   M05 M09 M30 ;

                                                                         More examples..........!!!!

DESCRIPTION OF PROGRAM 

N10- Tool change command , select tool no. 6
N20- Absolute co-ordinate command , cancel canned cycle command , selection of  XY plane, rapid command, work coordinate for tool positioning at  X0 and Y0.
N30- Tool height offset compensation command , where tool is 100 along Z axis , tool hight code H4.
N40- Spindle on clockwise , speed is 1500 rpm .
N50- Coolant ON .

N60- Return to R-plane in canned cycle , Drilling cycle command, Incremental command ,first position is X30 and Y0 Depth of drilling is 45 , R- plane distance is 5 ,feed rate per minute is 120 . 

After that second drilling position is X30 from current position and Y0 because we provide incremental command  and no of repeation K4 (repeating operation), similarly reaming operation will perform.

N70-Tool return initial position ,Absolute co-ordinate command(cancel incremental command), cancel canned cycle , rapid command , where tool along Z axis is 100 .

N80-  Spindle off , coolant off, Main program end .