On Jun 3, 2014, at 9:10 PM, Ted Mittelstaedt wrote: > On 6/2/2014 6:28 AM, Charles Lepple wrote: >> There was also this discussion last summer (similar to Ted's printer idea, >> but lower power): >> >> http://news.gmane.org/find-root.php?message_id=20130703045347.55D4172182%40mail.gishpuppy.com >> > > That one does not monitor for low battery.
I'm not saying I would do that, but a lot of people seem to only want an on-battery notification, and a shutdown timer if it stays on battery too long. >> I'm not a huge fan of polling when edge-triggered events are available. >> (That said, dummy-ups polls its state file once a second, and that could be >> improved upon with something like inotify.) Forget I said that - it's masked by the inherent polling loop in drivers/main.c. All of the NUT drivers poll at some frequency, and upsd makes sure they update often enough to not be considered stale. Re-reading the state file for dummy-ups each time probably isn't a big deal, but I will openly admit I haven't benchmarked this. > Say what? A lot of those setups connect DSR to the relay contact and when > that line isn't raised high the serial port under UNIX is closed - why does > the generic UPS driver still attempt to poll it????? Sloppy > coding? Or maybe just the desire to interface with models which don't wire their ports that way? (I should clarify what I mean by "poll": I'm referring to a select() loop with a timeout, so this is not buzz-looping.) > The hardware design is so that the driver can go to open the com port then > just block until DSR is asserted. Then you can start the polling, looking > for the CD line to go high (indicating a low battery) Tell that to the designers of the 20 other UPS configurations that are listed in genericups.h ;-) Note that some of those configurations don't even support a positive shutdown signal from the PC. >> In most cases, you can add a devd (FreeBSD) or udev (Linux) rule that >> triggers when a device disappears, without affecting normal operation of >> that device while it is connected. Both devd and udev will simply run all of >> the matching rules when the specified action occurs. >> > > the hack posted (inserting a relay in a spare mouse, really!?!?) that you > linked to is really unbelievable. We all have different standards for reliability. None of my machines have contact-closure UPSes, but someone else might come along and point out that I really should have dual power supplies. -- Charles Lepple clepple@gmail _______________________________________________ Nut-upsdev mailing list [email protected] http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/nut-upsdev
