[Nut-upsdev] NUT shutdown on 'building alarm' (

Bruce Allen ballen at gravity.phys.uwm.edu
Sat Jun 3 18:22:35 UTC 2006


Thanks for your note.  Do I understand correctly that your suggestion 
would involve running BOTH the bcmxcp driver (monitoring the Powerware 
9315 UPS) and also running the genericups driver (monitoring the 

If I have understood correctly, this is a good idea.  We're physicists so 
the idea of wiring a thermostat to a serial port doesn't scare us.  This 
would also make it easy to independently monitor the temperature at a 
number of different places in the room.


On Sat, 3 Jun 2006, Arjen de Korte wrote:

> Bruce Allen wrote:
> [...]
>> So I am checking with the list, to ask if the functionality that I
>> describe above is already available with NUT or if I need to modify the
>> driver so that a building alarm gets treated in the same way as an 'On
>> battery' event.
> I wouldn't mess with the driver. So far, there is little/no support for
> these additional inputs that some UPS apparently have. Since people may
> hook up quite different signals to them, this would inevitably mean that
> you would need additional configuration parameters for them to define
> the function. I foresee quite some additional coding needed and a lot of
> confusion on how to use them.
> Instead, it may be a lot easier to make use of the 'genericups' driver
> and hook up your thermostat so, that it changes the serial input line
> from the 'OL' the 'OB+LB' signal. This solution would not require any
> changes to drivers and furthermore it would be immediately clear what
> the reason of the shutdown is (and not 'faking' a power out/low battery
> event where there isn't).
> If you can find someone to make the necessary hardware (as simple as a
> DB-9 plug, one 10k resistor and a couple of meters of wire), this may be
> a much easier solution. Connect RI and DCD together, connect a resistor
> from there to RTS and the thermostat to DTR. Then, the following entry
> to your ups.conf file (change the port to whereever you connected this
> to) would be sufficient to monitor your thermostat:
> [thermostat]
> 	driver = genericups
> 	port = /dev/ttyS0
> 	upstype = 1
> 	desc = "Room temperature limit switch"
> Lastly, you would need some modifications to upsmon.conf to allow
> systems you want to shutdown to monitor the thermostat.
> Arjen

More information about the Nut-upsdev mailing list