Digi ports are configured in the same way standard communication ports /dev/ttyS0 and /dev/ttyS1 are although the name of the getty that configures your port varies from system to system. The following information is only meant to serve as a guide.
dl:2345:respawn:/sbin/getty ttyD1 DT9600 vt100
D1:23:respawn:sbin/getty -L ttyD1 19200 vt100
T3:23:respawn: /sbin/mgetty -x0 -s 115200 ttyD3
Note: Altpin should be off on Digi DB25 ports with a 10-wire cable. Modems wired to RJ-45 Digi ports with 8-wire cable should have altpin turned on. You can do this by editing the /etc/digiepca/rc.epca file, adding a line at the bottom of the file for each port. For example:
ditty altpin /dev/ttyD0
ditty altpin /dev/ttyD2