URGENT RXTX SERIAL PORT

[Nanou]

Hello


This is my situation :
A PC under OS MandrakeLinux 10.1
A machine branched on the serial port
I use jdk1.5 and the rxtx API

Opening the port seems good, i send data to the machine but when i read
th response i have a buffer with bytes null.
I have tried to sniff the serial port but i don't understand the data i
intercept, i don't recognize my protocol !
I don't know how i can debug to know what's wrong.
Any help will be welcome.
Thanks

Nanou