[KLUG Programming] looking for suggestions

[Dirk H Bartley]

Greetings

I am looking to accomplish a task at work.  What I want to do be able to
communicate to cnc machines which have serial ports for file transfers. 
A standard way is to have an m$ box next to the cnc machine with some
standard communication software capable of transferring files back and
forth between them.  Then network the host.

Another way is to throw money at the problem.  There are at least three
companies that will take $500-600 per wired/wireless device.  Then force
you to spend $1500-2000 on a server package to connect to these devices
+ $100 per cal per machine.  What a ripoff.  The server package is
supposed to do some version control but give me a bleamin' break.  Were
talking $5,500 just to conveniently transfer files like we want to that
way.

I'm thinking about the possibility of a multi part solution.

1) must connect to these machines in a preferably wireless fashion. 
Wires would be ok but would make choosing to rearrange in the future
more difficult.  (the connection must be serial)

2) must be able to download/upload files through this serial port to a
central location.  Here is the tricky part.  Our cnc programmer wants to
be able to prompt the send from a host computer to the cnc machine with
a send from the cnc machine.  The file would be a short file with the
instructions to send me a file named 01234345.

3) version control.  This is the easy part.  cvs and I feel comfortable
with that.  It would just have to be scripted in some fashion or
another.

To solve 1) 
        does anyone have any favorite inexpensive single or double port
serial
server they are familiar with.  It would need to be configured to show
up as a native serial port to preferably both m$ and linux.
        is there open source software available to make a serial port on
one
linux host available to another host.  Ideally this would be like an
ltsp client that would exist for the sole purpose of being a remote
rs232 port for another machine.

To solve 2)
        transferring files through linux serial ports sounds like a
difficult
proposition to a cnc.  What kind of software exists for serial port file
transfers.  Minicom for one but I'm looking for something scriptable or
perl or c code I can start from and pull up the sleeves on.  I'm sure I
need to find out the specs on what kind of transfer these machines do. 
(xmodem, zmodem or whatever.)
        I think I'd have to write some code to have a daemon listening
on these
serial ports for a send at all times.  Then when a send occurs, parse
the file and determine if it is a send of an update or a request for a
send.  What language would work best for this?

To solve 3)
        I'm sure I can handle this one.  cron, cvs and scripts sound
good to
me.

I'm looking for input.  Like what similar software currently exists for
serial port transfers.  I'd evan take a "Dirk your crazy, tell the boss
he has to spend the $5,500 and throw money at the problem.  It'd be
worth it.

Dirk