[Nut-upsuser] Setting offdelay and ondelay in Smart-UPS 1500 RM units

Javier Miqueleiz javier at miqueleiz.com
Thu Nov 11 17:39:50 UTC 2010

Hello there.

Have been experimenting with an APC Smart-UPS 1500 RM and would like to share
the results of my research. I hope this could be of help to people having this
kind of units. I would also like to give something back to the NUT community. :)

Here are the details of the unit in question (a 1500 VA rack mountable one):
  Model: Smart-UPS 1500 RM
  Firmware revision: 617.3.I
  USB firmware revision: 1.5
  Manufacturing date: 2003/06/03

The unit can be monitored with NUT, no problem at this. But when turning it off
an back on, the "offdelay" and "ondelay" parameters from "ups.conf" aren't

This unit uses a different HID path than the stardard one for sending a
"load.on.delay" command. As the driver (usbhid-ups) can't find this command,
it has to revert to rebooting the UPS. The HID paths involved are:

- "UPS.PowerSummary.DelayBeforeStartup": the standard command for triggering
a "load.on.delay" in USB units.
- "UPS.Output.DelayBeforeStartup": used in this unit for triggering a
"load.on.delay". The former doesn't exist.

If you add the HID path "UPS.PowerSummary.DelayBeforeStartup" to "apc-hid.c",
the driver will be able to use the "load.on.delay" command. And it will send a
"load.on.delay", "load.off.delay" at shutdown. This way, the "offdelay"
parameter will be honored. (The patch for this is trivial. Could post it if
someone is interested).

With regards to "ondelay", the unit doesn't fully honor it. Seems to have its
quirks on this. Here are my results.

- offdelay>=0, ondelay=-1: the unit will shut down the load at the specified
delay. And it will remain off. To turn it back on, the power-on button on the
front panel must be pressed.
- offdelay>=0, ondelay>offdelay: the unit will shut down the load at the
specified delay. The UPS will turn it back on as soon as the external power
is on. The "ondelay" is not honored in this case.

Hope this could be of help.

Kind regards to all. ;)

---- Javier Miqueleiz <javier.PLEASE.DONT at SEND.ME.SPAM.miqueleiz.com> ----------

  "There's nothing to it. You just have to press the right keys with the right
    force at the right time, and the organ will produce the nicest music all
     by itself."


More information about the Nut-upsuser mailing list