usb serial device problem

[andy baxter]

I have been working on an electronics project which uses an arduino 
board - a small board with a microcontroller on it that plugs into a usb 
port and sends and receives data as usb serial. The program on the board 
sends strings like '0, 19, 25' etc. When I monitor the usb port using 
the monitor built into the boards development program, this is working 
ok, but when I try 'cat /dev/ttyUSB0' (or run a program I'm trying to 
write to interpret the data on the computer), it just opens and closes 
the file without printing anything. Can anyone help with this, or 
suggest a better place that I should ask for help?

thanks,

andy baxter.