OPNsense Forum

English Forums => General Discussion => Topic started by: bedub1 on June 27, 2025, 06:14:43 PM

Title: Serial Port for APC UPS
Post by: bedub1 on June 27, 2025, 06:14:43 PM
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 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? 
Title: Re: Serial Port for APC UPS
Post by: Patrick M. Hausen on June 27, 2025, 09:56:59 PM
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*
Title: Re: Serial Port for APC UPS
Post by: bedub1 on June 27, 2025, 11:56:22 PM
Success!  APCUPSD is now setup to access the UPS via /dev/cuau0.