Serial-USB device node?

I have a terminal hooked to a DB9 connector on my BB that works fine as a serial console (/dev/ttyO0), but I can’t seem to get a USB-serial adapter cable to work so that I can connect more terminals. I can see agetty running on /dev/ttyGS0 – is that the miniUSB port? What tty is associated with USB-serial cable connected to the regular USB port?

/dev/ttyGS0 mean when your otg port connect to another host , like PC in Windows , You will get a serial port via USB

if your usb-serial adapter connected , you will get /dev/ttyUSB0 in common case.

Thanks for the tip. I’m getting a /dev/ttyUSB0 device node when I connect a USB-serial cable, but it remains a dialout port and I can’t spawn an agetty from /etc/inittab.

just make it clear , do you connect your DB9 cable with USB port on BBB ?
From host site , You can NOT use getty , You should use minicom