Programming
Sources and Test Commands
Serial Port
Null Modem Test on Command Line
* You need 2 computers with serial ports to quickly test the serial
data transmission.
* Connect the
computers via a nullmodem cable (RX and TX is crossed)
* Make
sure that the "/dev/ttyS0" device allows the user to read and
write !
* On the
receiving computer type in at the command line (ttyS0 is equal to COM1)
user:~$ read TESTMSG < /dev/ttyS0
and
wait ...
* On the transmitting computer type in at the
command line
user:~$ echo 0023testmessage2323 >
/dev/ttyS0
the message is sent to the receiving computer
* On the
receiving computer the command line prompt should show up again,
because the message was received, and read the message with
user:~$ echo $TESTMSG
0023testmessage2323