In message <[log in to unmask]>, JoAnn Amerson
<[log in to unmask]> writes
>Good morning.  I am a relatively new printed board designer who unfortunately 
>is unable to get a straight answer out of anyone here.  We are currently using 
>Cadstar For Windows 2.2.2 to design our boards.  After the layout has been 
>approved by everyone, we view the spool files before sending them on for 
>prototyping or release in Cam350 or ECAM (depending on who has the key).  We 
>currently import the spool files and convert them using RS-274.  We have the 
>option of using RS-274-X though.  Could some kind soul explain the difference 
>to me?  No one here can - we are all just winging it.  When I ask, I'm told 
>"That's the way we've always done it."  I refuse to accept that as a valid 
>reason.  No one here *ever* uses the IPC standards even though we do have a 
>copy of some of them on hand.  (Scary, ain't it?)
>
>I'd really appreciate some straight answers from others in the industry.  My 
>boss keeps saying "But the boards work.".  Surely they must be  a better way 
>and a more intelligent answer to my questions.
>
The basic gerber data only tells a photoplotter when and where to draw a
shape. It doesnt give it any details about what shape and size that hape
is. That is why at the moment you will also be importing an aperture
list to go with any gerber data. Unfortunatly since there is no standard
for the layout of an aperture list this can be tedious so the Gerber
data was expanded (hence the X) to include a standard aperture list at
the beginning. At the moment when loading basic gerber data you will
have to tell your CAD system if it is metric or inches. Again extended
gerber has a standard command in the file to do this automatically.
In the end what this achieves is that you can be supplied with just 1
file and it conatins everything you nedd to know to plot it without any
manual intervention or extra files.
Hope this helps.
Best regards,
-- 
Sam Kelly

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