Nut upsdev - Dec 2007 - Tripplite OMNI1000LCD Watchdog

Hello Nut Devs,

I'm working with usbhid-ups and a Tripplite OMNI1000LCD. I used a USB packet
sniffer to discover something cool about the watchdog feature in this unit.
(not sure if the other OMNI-X-LCD models work the same or not.) Basically
there's a single HID variable at Report ID 0x52
(UPS.OutletSystem.Outlet.ffff0092) that's one byte (0-255 int) and it
contains the Watchdog timeout value. If it's set to zero, the watchdog is
effectively disabled. If it's set to >0, it represents the amount of time
(in seconds) the UPS will count down to reboot if it looses comms with the
PC. Tripplite's PowerAlert software just writes a user-assigned number to
this location to enable watchdog.

I've looked at the code for 2.2.0, 2.2.1-pre, and SVN rev. 1170 (12-08-2007)
and none of them seems to implement watchdog in usbhid-ups at all.

Could anyone point me in the right direction on how to code
ups.watchdog.status and reset.watchdog in usbhid-ups?

Better yet, could ups.watchdog.timeout or something similar be added to the
NUT variables list? I'm going to hack together a use case for this watchdog
feature, because I REALLY need to use it now, however I'd like to help get
this feature into the main dev tree if possible.

Thanks,

Thomas Golding
Information Technology Engineer
World Radio Link
208-733-3551 ext. 14
thomasg at worldradiolink.com

Thomas Golding wrote:
> I'm working with usbhid-ups and a Tripplite OMNI1000LCD. I used a USB
packet
> sniffer to discover something cool about the watchdog feature in this unit.
> (not sure if the other OMNI-X-LCD models work the same or not.) Basically
> there's a single HID variable at Report ID 0x52
> (UPS.OutletSystem.Outlet.ffff0092) that's one byte (0-255 int) and it
> contains the Watchdog timeout value. If it's set to zero, the watchdog
is
> effectively disabled. If it's set to >0, it represents the amount of
time
> (in seconds) the UPS will count down to reboot if it looses comms with the
> PC. Tripplite's PowerAlert software just writes a user-assigned number
to
> this location to enable watchdog.
That is a highly dangerous feature. If someone accidentally removes the
USB plug, it would trip the watchdog.
> I've looked at the code for 2.2.0, 2.2.1-pre, and SVN rev. 1170
(12-08-2007)
> and none of them seems to implement watchdog in usbhid-ups at all.
No, although it can be done pretty easily in the subdriver. There is no
need to do this in usbhid-ups (and we won't do that either, see below).
> Could anyone point me in the right direction on how to code
> ups.watchdog.status and reset.watchdog in usbhid-ups?
See if what I came up with in the trunk (r1175) suits your needs. The
following commands control the watchdog:

	upsc <upsname> ups.watchdog.status (shows time left)
	upscmd -u <user> -p <pass>] <ups> reset.watchdog[=seconds]

By default, the latter command will write '60' to this variable if
called without the optional seconds, but you can override this. You'll
need to hack up a script that periodically calls this command to keep
your watchdog happy.

This feature is far too dangerous to include in the mainstream NUT, so
adding these variables to the tripplite-hid subdriver is as far as I
want to go.

Best regards, Arjen