gnome-power-manager Shows Only Wireless Mouse Battery, no AC or Other Devices

I'm diagnosing potential power issues with a Ubuntu 20.04 workstation and just attempted to interact with Power Statistics, a/k/a gnome-power-manager.

Unfortunately, the only hardware object that appears in the GUI is the wireless mouse battery. No other objects appear, including adapters, processor, RAM, on-board controllers, or the AC object. I wouldn't expect the battery or monitor objects to appear because this is not a laptop but nothing in the GNOME Power Manager Manual suggests that the utility fails for devices connected to non-laptops, or that the AC object in particular fails in such cases.

Also, the current dconf settings don't seem to reflect any other objects or the ability to add new ones, and my research has yet to uncover any suggestion that one can add a key to the utility's schema to address this.

The question is, does a means exist to configure GNOME Power Manager to recognize and report on adapters, other attached devices, and the AC object, or have I simply encountered undocumented limitations of the utility?

If the latter, then what utilities exist that can report power statistics for the system, i.e., power in or by rail, and power consumption by device, specifically by adapter/controller, processor, and perhaps RAM? I've googled around and so far have come up with powerstat, powertop, and upower and am about to start fiddling with dmidecode but haven't yet found any definitive information less than 7-8 years old.

Any assistance that can keep this from turning in to a rabbit hole would be most appreciated.

re: "The exact problem is that the system emits an especially loud four-pulse alarm every two seconds, every 12 hours at 9:58, initially for 10 minutes and now, 23. This persists through, and during, reboot/reset. Nothing appears in any log. The system continues to operate flawlessly.".

Power Manager

Reset the Power Manager... shutdown the computer, and then hold down the power button for ~20 seconds. Then reboot normally.

APC UPS

APC Back-Ups BE600-M1

I suspect that the problem is with the APC Back-Ups BE600-M1, and it's doing the beeping. It sounds like it has a power issue, battery issue, or it's failing, or it's overloaded. Do not connect printers or fax machines (motorized devices) to the backup plugs of the UPS. Connect the UPS to the computer using a standard USB "printer" cable, and install apcupsd to monitor it via syslog, and the Power Manager GUI.

Note: The apcupsd utility requires some minor config file edits to make it work correctly. See /etc/default/apcupsd and /etc/apcupsd/apcupsd.conf.

Note: See https://www.apc.com/us/en/faqs/FA158827/

BIOS

Asus P9x79-E WS v.1

You have BIOS 1602. BIOS 1704 is available here.

Update #1:

The beeping came from an alarm clock on the site.

The beep issue has been otherwise resolved but in the course of things, I encountered several inconspicuous / undocumented apcupsd configuration steps necessary to get the apcaccess command to work.

First, connect the APC unit to the computer by USB cable.

Second, edit /etc/apcupsd/apcupsd.conf as appropriate for the APC unit, and edit /etc/default/apcupsd to reflect that the former has been configured. This will allow the daemon to launch once it is started. This is well documented elsewhere.

Third, actually restart apcupsd.service:

sudo systemctl restart apcupsd

At this point, run apcaccess, although this may return some connection errors, in which case:

Fourth, open port 3551/TCP to and from localhost / 127.0.0.1. If using iptables, this rule will work:

iptables -A INPUT -p tcp --dport 3551 -s 127.0.0.1 -d 127.0.0.1 -j ACCEPT

Depending on configuration, a corresponding egress rule in the OUTPUT table also may be necessary. Logging iptables drops is a big help in diagnosis.

Fifth, edit /etc/hosts.allow to add the following line:

apcupsd: 127.0.0.1

That got everything running, for this installation, at least.