Re: RS274
Posted by
Jon Elson
on 2000-02-05 21:33:59 UTC
Ian Wright wrote:
standard, registered by a formal comittee. It was designed as an
extension to the Gerber photoplotting language, which is, in fact,
a particular format of RS-274. The old RS-274D was used very
much in the printed circuit board industry, for photoplotting master
artwork, and also for drilling the PC boards. Bot of these formats
used RD-274D with no decimal points, but the plotting used
suppressed trailing zeroes, while the drilling used suppressed
LEADING zeros. Very confusing! Well, the other problem is
that they used the D word to select an 'aperture' to 'flash' onto
the film (sort of like a tool-change), but then they also use
D01, D02 and D03 to select move without drawing, move to
and flash when you get there, and draw (with light) to coordinates
(X,Y). Also, very confused, but it made sense for the hardwired,
no-CPU controllers that ran those original machines.
The problem came up when more sophisticated PC boards were being
done, and they had dozens to hundreds of apertures to be manually
loaded into the photoplotter (either physically, or as bitmaps
specified in a separate 'aperture' file). Mistakes were common,
ruining lots of boards. So, the idea was to include the aperture
data at the top of the file, as comments in format RS-274, but
to be read as information by the RS-274X photoplotter
program. So, RS-274X has no useful extensions except for the
circuit board industry, as far as I know.
Jon
> From: "Ian Wright" <Ian@...>RS-274X is really a misnomer. It is not, to my knowledge, a true
>
> Hi,
>
> I can't remember whether it was this list or not where someone was
> asking
> about RS274 specs. However, here is a link to a 68 page .pdf document
> on
> RS274X which also seems to cover RS274D.
> http://www.barco.com/ets/data/rs274xc.pdf
standard, registered by a formal comittee. It was designed as an
extension to the Gerber photoplotting language, which is, in fact,
a particular format of RS-274. The old RS-274D was used very
much in the printed circuit board industry, for photoplotting master
artwork, and also for drilling the PC boards. Bot of these formats
used RD-274D with no decimal points, but the plotting used
suppressed trailing zeroes, while the drilling used suppressed
LEADING zeros. Very confusing! Well, the other problem is
that they used the D word to select an 'aperture' to 'flash' onto
the film (sort of like a tool-change), but then they also use
D01, D02 and D03 to select move without drawing, move to
and flash when you get there, and draw (with light) to coordinates
(X,Y). Also, very confused, but it made sense for the hardwired,
no-CPU controllers that ran those original machines.
The problem came up when more sophisticated PC boards were being
done, and they had dozens to hundreds of apertures to be manually
loaded into the photoplotter (either physically, or as bitmaps
specified in a separate 'aperture' file). Mistakes were common,
ruining lots of boards. So, the idea was to include the aperture
data at the top of the file, as comments in format RS-274, but
to be read as information by the RS-274X photoplotter
program. So, RS-274X has no useful extensions except for the
circuit board industry, as far as I know.
Jon