This Debian package of remote-tty expects the creation of symlinks in
/etc/remote-tty/dev/ to the appropriate device file for that console. For
example:

ln -s /dev/ttyS0 /etc/remote-tty/dev/myconsole

would enable the use of:

rconsole myconsole

to connect to the device that was on ttyS0. The addrconsole script will create
a suitable user account and the appropriate symlink for you, such that the
user can only get access to the serial console when they log in.