APT programming language - AbsoluteAstronomy.com

APT or Automatically Programmed Tool is a high-level computer programming language used to generate instructions for numerically controlled machine tools. Douglas T. Ross

Douglas T. Ross

Douglas Taylor Ross was an American computer scientist pioneer, and Chairman of SofTech, Inc.. He is most famous for originating the term CAD for computer-aided design, and is consider to be the father of Automatically Programmed Tools a language to drive numerically controlled manufacturing.-...

is considered by many to be the father of APT. APT is a language and system that makes numerically controlled manufacturing possible. This early language was used widely into the 1970s and is still a standard internationally.

Overview

APT is used to program CNC machine tools to create complex parts using a cutting tool moving in space. It is used to calculate a path that a tool must follow to generate a desired form. APT is a a special-purpose language and the predecessor to modern CAM systems. It was created and refined during the late 1950s and early 1960s to simplify the task of calculating geometry points that a tool must traverse in space to cut the complex parts required in the aerospace industry. It was a direct result of the new numerical control technology becoming available at that time and the daunting task that a machinist or engineer faced calculating the movements of the machine for the complex parts for which it was capable. APT was created before graphical interfaces were available, and so it relies on text to specify the geometry and toolpaths needed to machine a part. The original version was created before even FORTRAN was available and was the very first ANSI standard. Later versions were rewritten in FORTRAN. APT is in the public domain.

APT shares many similarities with other computer programming languages such as FORTRAN. A general-purpose computer language takes source text and converts the statements to instructions that can be processed internally by a computer. APT converts source statements into programs for driving numerically-controlled machine tools. Typically, the output from an APT processor is a CL or "Cutter Line" file which is then run through a post-processor specific to the desired control - machine pair. The resulting file is then run by the control of the machine to generate tool motions and other machine actions. Most commonly, this file is in some form of RS-274 format instructions, commonly known as G-code

G-code

G-code is the common name for the most widely used computer numerical control programming language, which has many implementations. Used mainly in automation, it is part of computer-aided engineering. G-code is sometimes called G programming language...

Example Program

PARTNO / APT-1

CLPRNT

UNITS / MM

NOPOST

CUTTER / 10.0

$$GEOMETRY DEFINITION

SETPT = POINT / 0.0, 0.0, 0.0

STRTPT = POINT / 70,70,0

P1 = POINT / 50, 50, 0

P2 = POINT / 20, -20, 0

C1 = CIRCLE / CENTER, P2, RADIUS, 30

P3 = POINT / -50, -50, 0

P4 = POINT / -30, 30, 0

C2 = CIRCLE / CENTER, P4, RADIUS, 20

P5 = POINT / 50, -20, 0

L1 = LINE / P1, P5

L2 = LINE / P3, PERPTO, L1

L3 = LINE / P3, PARLEL, L1

L4 = LINE / P1, PERPTO, L1

PLAN1 = PLANE / P1, P2, P3

PLAN2 = PARLEL, PLAN1, ZSMALL, 16

$$MOTION COMMANDS

SPINDL / 3000, CW

FEDRAT / 100, 0

FROM / STRTPT

GO/TO L1, TO, PLAN2, TO, L4

TLLFT, GOFWD / L1, TANTO, C1

GOFWD / C1, TANTO, L2

GOFWD / L2, PAST, L3

GORGT / L3, TANTO, C2

GOFWD / C2, TANTO, L4

GOFWD / L4, PAST, L1

NOPS

GOTO / STRTPT

FINI

Overview

Example Program

Further reading