24
M99 --- End of subroutine returns to the main. When this system is not specified, M30, will repeat the
routine.
10.2 Auxiliary Function M code
M03 --- Spindle forward. Use this command to the spindle currently specified spindle speed
counterclockwise (CCW) rotation.
M04 --- spindle reversal. Use this command to the spindle currently specified spindle speed clockwise (CW).
M08 --- cooling open.
M09 --- cooling off.
Machine tool manufacturers from the self-developed machine function is set to M codes (such as machine
open / close), These M codes, please refer to the instruction manual that comes with the machine.
11 Tool Compensation
11.1 Tool Length Compensation (G43, G44, G49)
The need for frequent exchange processing center run the tool, if the work coordinate system unchanged, will
take place after the replacement tools of different lengths parts too serious accident cut or hit the bed, Therefore,
the introduction of numerical control system tool length compensation algorithms, resulting tool length
compensation command.
In the Z-axis workpiece zero setting, so that the spindle taper plane coincides with the Z axis of the
workpiece zero set theory, When we use each tool length allows the machine tool and the workpiece zero by
increasing a distance, so that each tool tip just on the surface, this is the height of the tool length compensation
value. As shown in Fig. 11-1, H1, H2 for the tool length compensation value. The compensation value in the
system function tool offset / correction set in the tool interface settings.
Fig. 11-1 Length compensation principle
Format:
G43H_
；
Tool length compensation positive;
G44H_
；
Negative tool length compensation
G49 or H00
；
Tool length compensation cancel
G43 instruction is a positive tool length compensation, the actual position of the Z-axis reaches of command
value compensation value and location; G44 command is negative tool length compensation, the actual position of
the Z-axis reaches position to command value compensation value is subtracted. G43 or G44 are modal, H_
specified compensation number is modal use this instruction, the programmer when writing machining programs
can regardless of the length of the tool and consider only the tip location. After wear or damage do not need to
change the machining program to replace the new tool, tool offset value can be modified directly.
H in the range of 000 to 099. H00 means cancel tool length compensation value. Another way to cancel tool
length compensation is the use of instruction G49. When the NC instruction execution to G49 or H00 ,
