#500 = 2440; (LENGHT MM)
#501 = 1220; (WIDTH MM)
#502 = 5; (GAP)
#503 = 6; (STEP Y)
#506 = 2; (DEPTH Z)
#505 = #502; (START Y)
#507 = FIX[[#501-#502]/[#503*2]];
G17 G21 G90 G54 G40 G29;
M06 T1;
G43 H1;
M03 S1000;
G00 X#502 Y#502 Z10.;
N50 IF [#507 EQ 0] GOTO 100
G00 X#502 Y#505 Z10.;
Z5.;
G01 Z-#506 F100;
G91
X[#500-[#502*2]] F150;
Y#503;
X-[#500-[#502*2]];
Y#503;
G90;
G00 Z10.;
#507=#507-1;
#505=#505+[#503*2];
GOTO 50;
N100;
M05;
G91 G28 Z0.
G90;
M30;