Defining a point PT in an Apt programming

                        In NC Programming the APT programs plays a major role, the geometries are defined by APT programming and then converted into G-codes giving motions to the CNC machine.

  Defining a point in the APT programming, the statement used is GOTO/P1; the programmer must know where P1 is located before the statement can be effective. P1 therefore must be described in a geometry statement, prior to its use in the motion statement GOTO/P1.

The geometry statement for defining a point is P1 =POINT/X co-ordinate, Y co-ordinate and Z  co-ordinate where, P1 is known as a symbol Any combination of letters and numbers may be used as a symbol providing the total does not exceed six characters and at least one of them is a letter.If the Z co-ordinate is zero and the point lies on the XY plane, the Z location need not be noted.Here “PT’ is a POINT. This word is a vocabulary word. Throughout, the designers of APT have tried to use words that are as close to English as possible. A slashfollows the vocabulary word and is followed by a specific description of the particular geometry, such as the coordinates of the point P1. AnAPT programming statement for P1 might appear as P1 = POINT/1, 5, 4. The 1 would be the X ordinate; the 5, the Y ordinate; and the 4, the Z ordinate. Lines

Examples for the Point definition in APT programming:

There are other ways of defining the position of a point, such as at the intersection of two lines or where a line is tangent to a circular, intersection of two circles, single point in space etc. following pictures shows the different ways of defining the Point in an APT programming.

Point in Space: Any point in the space can be defined as shown below.

APTSource code:
P1=POINT/4,5,2
P2=POINT/2,2






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Intersection of two lines: Point can be created by intersection of two lines.

APTSource code:
P1=POINT/INTOF, L1,L2













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Intersection of two lines: Point can be created by intersection of line and circle. there are two possibilities, it can be written as below.

APTSource code:

P1=POINT/XLARGE,INTOF,L1,C1
                       OR
P1=POINT/YLARGE,INTOF,L1,C1
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P2=POINT/XSMALL,INTOF,L1,C1
                       OR
P2=POINT/YSMALL,INTOF,L1,C1

Note: The X and Y co-ordinates of P1 is Larger than the X and Y co-ordinates of P2.


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Intersection of two Cirlces: Point can be created by intersection of circles. there are two possibilities, it can be written as below.

APTSource code:
P1=POINT/XSMALL,INTOF,C1,C2
                         OR
P1=POINT/YLARGE,INTOF,C1,C2
---------------------------------------
P2=POINT/XLARGE,INTOF,C1,C2
                         OR
P2=POINT/YSMALL,INTOF,C1,C2

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Intersection of a radial line and a circle: Point can be created by intersection of circle with a radial line can be written as follows.

APTSource code:
P1=POINT/C1,ATANGL,20

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Intersection of a radial line and a circle: Point can be created by intersection of circle with a radial line can be written as follows

APTSource code:
P1=POINT/CENTER,C1










This is how the APT codes can be written in APT programming. All software generates the APTSource fiiles using the PPtables used while generating. PPTables are the machine defined files where all the cycles and the movements are in machining standardized format