Confusion with Serial Port Consoles

[David McAllister]

I have been attempting to use the serial port on a D Class server to connect with a new J Class I got in, but am unsure of the terminal server to use or the correct command line. I have been attempting to use cu, but I don't seem to get a connection. I have setup the D Classes serial ports in the /etc/uucp/Devices file but still nothing. What am I doing wrong?

[A. Clay Stephenson · Accepted solution]

Hi David,

This can be quite difficult since you may be fighting several problems at once. When I am initially trying to get two boxes talking, I initially avoid uucp/cu - it's just too complicated and error prone. The easiest method I've found is to use kermit.

So,
On the D-box (I think it's the calling box)
I would go into the /etc/inittab and set the port to off and do an init -q to force a reread on /etc/inittab.

execute kermit
set line /dev/tty0p1 (I'm guessing)
set speed 9600
connect

If you are lucky, you're in and you see a login prompt.

BTW - all your problems could be the cable.

After you get kermit working, the uucp setup should be easy.

Hope this helps, Clay.

[David McAllister]

I have tried your recommendations Clay, but when I try to set the line, I get cannot open device error message. (I have 4 possible devices, 1 mux with 3 ports 0,1,7 and the built in serial port tty1p0.) I have verified that the devices are not defined in the /etc/inittab file and there are no getty sessions running for them.

[A. Clay Stephenson]

Ok David,
I suggest that youusde the build-in port at least initially.
We are now going to try to force some status lines. Normally this would be done by you cable.
From a separate session,
stty -crts rtsxoff ctsxon < /dev/tty1p0

If this command does not hang, then you should be able to issue a kermit set line command.
I assume you are running as root so that we are not also fighting permission problems as well.

Clay

[David McAllister]

CLay thanks, the first was the correct answer, the device files had gotten erased while I was playing around trying to fix it earlier.