Re: [CAD_CAM_EDM_DRO] Re: Optimizing cutting paths - The proof

In article <9mo0i2+o1qj@...>, Fred Smith <imserv@...>
writes

>Alan and others,
>
>When transferring files over the internet, it is important to
>understand that ascii files are subject to lightning strikes,
>wiretaps, any kind of static might affect the transmission of the
>data around the world. Therefore if you try to use an ascii format
>to define a drawing it might have a problem.
>

Oh please...

Just about all the original Internet protocols are based around text
transfers. So reliable is the transfer of text (as long as it is seven
bit ASCII) that email attachments are converted to text for
transmission. If there is a problem, it is potentially in the
transmission of eight bit ASCII and binary files that are treated as
eight bit ASCII.

Data, in general, transmitted via the Internet is remarkably stable. The
protocols used are error detecting and error correcting. I don't recall
a provable error in data transmitted from end to end. Sure there may
have been all manner of mess in the middle but the Internet protocols
guarantee correct delivery (although they don't actually guarantee
delivery itself).

You are much more likely to suffer data corruption on your own PC when
just copying files from folder to folder. There is no error checking
involved by default.

Just send your files and be done with it. Any errors due to file formats
are the responsibility of the software packages not the transmission
medium.

>As far as transferring files like DXF or IGES, that are ascii based,
>it is usually better to point to the link in hypertext and right
>click to "Save Target As", than to click on the link, load the file
>as text in your browser and then try to File-Save it. If you get a

Why would saving it twice make it more reliable?

>file that the only way is to display and then save, open it in an
>editor an dmake sure that the first lines are not blank. Often just
>removing the first blank lines will make the file usable.
>

Then again, the file may be rendered useless just by opening it in an
editor. Suppose the file should be in DOS format with a CRLF pair at the
end of each line and your editor saves the file with just a LF? This
kind of problem is surprisingly common. The less you do to mess with the
file the better - unless you actually know what you are doing that is.



Peter Harrison
http://www.cannock.ac.uk/~peteh