Serial Port for APC UPS

[bedub1]

I want to connect my OPNSense box to my APC UPS via a serial cable.  The problem is I can't find the serial port information.

I run

Code Select Expand

ls -l /dev/tty* and it only shows 3 items:
/dev/ttyu0
/dev/ttyu0.init
/dev/ttyu0.lock

How do I find my serial port?  How do I get OPNSense to leave it alone, and not try to output console information via the port? 

[Patrick M. Hausen]

Set the primary console to VGA and the secondary to none and OPNsense will leave the serial interface alone. Also the "dialout" devices for services running on OPNsense to reach connected systems are named /dev/cu*

[bedub1]

Success!  APCUPSD is now setup to access the UPS via /dev/cuau0.