[Nut-upsdev] belkin-hid:

Arjen de Korte nut+devel at de-korte.org
Thu Aug 2 07:45:59 UTC 2007

>>     OL = ACPresent
>>     OB = !ACPresent
> I agree that this makes sense, and that the documentation in
> docs/new-drivers.txt should be updated to make this more clear. I am
> not sure I want to see OB when the load is off, though. Many low-end
> UPS's don't have separably switchable outlets.

Currently either the OL or OB status is shown, because of the following
lines in usbhid-ups:

	if (ups_status & STATUS_ONLINE) {
		status_set("OL");		/* on line */
	} else {
		status_set("OB");               /* on battery */

Historically, most (if not all) drivers treat these this way. Basically,
what OL/OB only say something about the UPS input only, not about the

>> Giving the fact that nowadays many UPSes have multiple switched outputs,
>> the OFF status is probably too course to be of much value. I think that
>> applications that need this, better look at the 'outlet.n.status'
>> values.
>> Short of the fact that this probably doesn't belong in the 'ups.status'
>> anyway, since it doesn't require immediate action from clients (if they
>> are powered by the UPS in question, they probably never see it).
> The OFF flag could be of interest when monitoring a UPS that is not
> powering the machine monitoring it. It may help a remote user trying
> to see the power status of another machine. Not all drivers/devices
> support outlet.n.status.

I'm not sure if I am very much in favor of using 'ups.status' for that.
Since this will be ambiguous for UPSes that DO have switchable outlets
(when would you decide to set this flag?), I think we should encourage the
use of 'outlet.status' and/or 'outlet.n.status' for devices that have
switchable outlets.

Best regards, Arjen

More information about the Nut-upsdev mailing list