Power Monitoring

Monitoring the status of APC Uninterruptible Power Supplies (UPSs) using UPS network management cards, wired networking and open source software


I use this system on a day to day basis to monitor the power status and environmental conditions of four UPSs, located in the house I live in and a separate garage building nearby. What you see here is the publicly available monitoring side of the system. As a whole, the system has two main purposes. The first is to isolate my equipment - consisting of computer systems, routers, network switches, my server, test gear, and lighting - from the ravages of unstable power, that inevitably come about in a rural setting. This isn't something new or something that will go away any time soon either, with climate change and new weather extremes. Even lines company Vector admits it to their shareholders.

The second goal of this system is to provide me with logging of power events such as outages, and data logging of all recorded parameters, as well as the ability to control and shut down the UPSs remotely, schedule shutdowns, cancel scheduled shutdowns, change UPS settings, and so forth. You can't access that part. At least, I hope not :)

The system consists of uninterruptible power supplies made by APC, two of which have APC network management cards installed, and two of which are directly interfaced via USB to routers running OpenWRT open source router firmware, and using the open source UPS monitoring software APCUPSD. The structure and content of the monitoring screens you see are produced by APCUPSD. I did not write this software. I did, however, write the CSS that formats the page into what you see, and write the JavaScript that updates it in real time, corrects several errors produced by APCUPSD, and provides the requested detail pages on demand. The CSS also uses nth-child selectors to produce a reduced mobile device compatible version.

I've also done quite a bit of work internally on the UPSs themselves, as you'll see over here.

You can view it in real time at the link above. If you're lucky, you'll tune in during a power outage or while AVR (automatic voltage regulation) is underway.