Conversion Directives in the Aperture List

The aperture file (.apt) also contains many directives that control the conversion. There are quite a few of these and they are summarized below. Some directives are used only in the dxf2gbr direction, others in the gbr2dxf direction and some in both directions. Some of conversion parameters can be specified from the command line (response file).

The following apt file directives define the Gerber format:

Directive Description
FONT name of the "default" text font to use in case that the desired font cannot be found. i.e. c:\wcad\asm501\text.shx
FONTDIR a directory where the translation engine should look for fonts found in the DXF file. i.e. "C:Program Files\AutoCAD 2002\support\fonts"
ARCRES the resolution (in degrees) used when arcs are broken into a series of segments. Typical values range from 6 to 15 degrees.
CIRCULAR If set to ON, the engine will convert circles and arcs in DXF into circular commands (G03) in Gerber. The CIRANG parameter determines whether 360 or 90 interpolation is used.
LINE AutoCAD lines have no width. This parameter points to a D-Code to be used when a line is found. The D-code should be defined in the aperture list and should be a round.
TEXT The D-code used for “processing” text. If follwed by a D-code
then the D-code specified will be used for all text.

If followed by a number (i.e. 7, 8)
then for each string of text the text height will be noted and the height will be divided by the value given. The next smallest round d-code will be used to stroke the text.
Page    1   |   2   |   3   |   4   |   5   |   6   |   7   |   8   |   9   |   10