Other Motion Commands 

As shown in the above motion command examples, the actual motion of the tool in geometric space is seen. However, the actual functions that need to be collaborated from the CNC machine tool are not present. The post processor commands provide that missing link in a part program to complete it. In the following a few of the postprocessor commands that are normally used are given.

COOLNT/ {ON, OFF, MIST, FLOOD, TAPKUL}

This specifies the type of cutting fluid application to be used and when to start or stop.

CYCLE/ {DRILL, FACE, TAP, BORE, REAM}, Z, {IPM, IPR, MMPM, MMPR}, feed, rapid_pl                     

IPM              -  Inch per minute

IPR                - Inch per revolution

MMPM           -           mm per minute

MMPR            -           mm per revolution

This command specifies the generation of a fixed sequence of motions similar to the canned cycles. z is the depth through the work material, which the tool has to travel with f, the feed rate given in the units specified. The rapid pl specifies the position of the rapid plane above the point where the cycle will be effective.

FEDRAT / {IPM, IPR, MMPM, MMPR}, feed

This specifies the rate at which the slides move in appropriate units as designated.

LOADTL/ tool no, magpos

It indicates the loading of the tool number, which will be loaded in the tool magazine position indicated.

REWIND

This command is inserted to rewind the control tape to a known tape mark, which is generally the start of the tape (part program).

SPINDL /  {SFM, RPM, SMM} , n , {CLW, CCLW}

SFM    Surface feet per minute

RPM    Revolutions per minute

SMM   Surface metres per minute

This command signifies the selection of spindle speed in appropriate units specified in the statement.

In addition to the postprocessor commands the compilation control commands also need to be specified to complete a part program. The compilation control commands relate more to the APT processor rather than with the geometry or machine tool. Some of these are given below :

PARTNO/ <literal string>

The PARTNO is used as identification for the part program and as such should be the very first statement in a part program. It should also be noted that in a given line PARTNO should appear in the first six character positions without any blanks. The length of <Literal string> will depend on the particular implementation, e.g. PARTNO/- LEVER 138C

The FINI statement is the physical end of a part program and should always be present at the end of any part program.

MACHIN/name, <parameters>

The MACHIN statement identifies the post processor to be used for outputting the necessary NC blocks. name signifies the name of the particular postprocessor identification name in literal strings, e.g. EXPOST, followed by < parameters > which initialises the various flags in the postprocessor program. The number of such parameters depends upon a particular implementation.

e.g.      MACHIN/FACPST, 2,1

When no postprocessing of CLDATA is required, then the following statement may be specified which would suppress the postprocessing.