HEIDENHAIN TNC 426 (280 476) - Manual (Page 90)

HEIDENHAIN TNC 426, TNC 430 63
4.5 Cr
eating and W
riting Pr
ogr
a
ms
4.5 Creating and Writing Programs
Organization of an NC program in HEIDENHAIN
conversational format.
A part program consists of a series of program blocks. The figure at
right illustrates the elements of a block.
The TNC numbers the blocks in ascending sequence.
The first block of a program is identified by BEGIN PGM, the program
name and the active unit of measure.
The subsequent blocks contain information on:
n The workpiece blank
n
Tool definitions, tool calls
n Feed rates and spindle speeds, as well as
n Path contours, cycles and other functions
The last block of a program is identified by END PGM, the program
name and the active unit of measure.
Defining the blank form– BLK FORM
Immediately after initiating a new program, you define a cuboid
workpiece blank. If you wish to define the blank at a later stage, press
the BLK FORM soft key. This definition is needed for the TNC’s
graphic simulation feature. The sides of the workpiece blank lie parallel
to the X, Y and Z axes and can be up to 100 000 mm long. The blank
form is defined by two of its corner points:
n MIN point: the smallest X, Y and Z coordinates of the blank form,
entered as absolute values.
n MAX point: the largest X, Y and Z coordinates of the blank form,
entered as absolute or incremental values.
10 L X+10 Y+5 R0 F100 M3
Block number
Path function Words
Blocks
You only need to define the blank form if you wish to run
a graphic test for the program!