I appreciate the reply,
I am talking to a Veeder Root Tank monitor.
Link to pdf, of the serial manual
http://www.veeder.com/object/576013-635.html
The 200 is the actual command sent to the device.
And I'm new to linux and the only way I got it to talk was to send the soh character. In windows all I had to do was open hyperterminal configure baud rate parity etc. and hit connect, then all I had to press was "ctrl + a" then "200" minus the quotations.
And it would bring up the soh (ctrl + a) symbol then 200 (which is the command) then the data then etx(end of text as you pointed out)
I just tried the CTRL-C like you said, and when I type it in it does return me to the ~ directory, but how do I echo it so that the program does it by itself?
This sounds funny but, the "hello_world" program I did in the book I bought a few weeks ago went back to it by itself. (I'm a newb, I know)
Thanks again for your help, if you need anymore information on the device let me know.