Re: G & M Codes?????????????

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Ken Ferrell" <zero-
kool@...> wrote:

>
> I was under the impression that for the G and M codes it was

Geometry and

> Machine, at least that's what our text book says, But it makes

quite a few

> questionable statements such as G codes are standardized, Yeah

right !!

G-codes are very standardized. G0, G1, G2, G3 are well documented in
the standards, as are G90, G91, G17, G18, G19, G41, G42, G40 and
most others.

The standard defines ranges of G-codes that are left to the
manufacturer to define as he needs/wants. The manufacturer defined
ranges will not be standardized beyond the fact that they are
defined as Manufacturer defined.

The standard is called RS-274D ( Published by EIA ). There is an on-
going attempt to create an ISO standard which will be the "official"
replacement for RS-274D. However the Japanese, who manufacture a
market dominating percentage of the commercial controllers will not
ratify the standard.

The RS-274D standard is copyrighted and the publishing standards
organizations aggressively pursue any unauthorized posting on the
internet.

To get a flavor for the standard, check out (google) the original RS-
274NGC standard that was used to write EMC. It was based on RS-274D
and an obsolete Allen Bradley controller. There are some quirks due
to the A-B connection, but it was the basis for today's EMC, Mach
and DeskCNC G-code interpreters.

There is a seperate standard for PCB's called RS-274X which is
substantially different from RS-274D because it is used to define a
graphical image of a printed circuit board, (to create resist
artwork and silkscreen graphic layout). It is also known as the
Gerber format. I don't know if there is an ISO standard for RS-
274X, but it should be much easier to define without a single
dominant committee member to satisfy. There are several archives of
RS-274X posted on the internet.

Fred Smith - IMService
http://www.cadcamcadcam.com/hobby