On Jan 2, 2024, at 1:49 PM, Kelly Byrd <[email protected]> wrote: > > My question for you all is what units ups.powersummary.runtimetoempty is > supposed to be in? This doc from USB.org: > https://www.usb.org/sites/default/files/hut1_4.pdf (Section 31.2) says > minutes,
Do you mean the Power Device Class documentation? I agree that the description on p.37 of https://usb.org/sites/default/files/pdcv11.pdf says minutes, but the last reference to RunTimeToEmpty on p.57 is embedded in a descriptor that specifies the units to be seconds. I think most manufacturers end up reporting seconds, since the descriptors tend to look fairly similar to the spec. > Is this just a case where real world UPS' are using seconds so we're stuck > with it now? That, and the fact that that the HID protocol uses a lot of base SI units. > I guess it's being pedantic, but IMO trying to measure a UPS remaining > runtime with accuracy is sort of silly. I noticed this because I'm cobbling > together a personal project that has absurd capacity for the load, somewhere > around 2-3 days from a fully charged battery and I'm using NUT's Arduino > driver to report things. To be honest, this is exactly the sort of thing that the Physical and Logical units are meant to address. You can keep the internal time-remaining counter in whatever format makes sense in the firmware, and specify some Logical units to map that back to seconds so you aren't sending 32-bit numbers for something with a really small range. I'm pretty sure there is one UPS where the shutdown timer settings are kept in minutes, and the NUT drivers expose seconds because the vendor specified a Physical-to-Logical factor of 60. - Charles _______________________________________________ Nut-upsdev mailing list [email protected] https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/nut-upsdev
