[Nut-upsuser] Fw: Interfacing a Contact-Closure UPS to Mac OS X and Linux

Roger Salisbury rojee at tpg.com.au
Sat Aug 21 09:17:34 UTC 2010

Hi David

As per the link 


& the final testing paragraph.

I have set up a Lantech UPS similiar to your write up for  your Powersure Proactive and Powersure Personal  UPS's

it shuts down OK.

BUT as with other  many UPS's during the 
wait period from low batt to start of shutdown ... IE 

[SHUTDOWNCMD "/sbin/shutdown -h +20"]

20 minutes in this case.

Reapplying AC power before the 20 minute mark stops the shutdown & all is normal again.

This option isn't working on my setup.

What happens in your setup.

What I could do a run a script that cancels the shutdown.  ... with   " shutdown -c" .

But there is no alert as to AC power being restored.

Pulling power before "LOW BATTERY"  there is an alert.

IE from /var/log/syslog .............

Aug 21 12:12:05 roj-desktop upsmon[18721]: UPS powerpal at localhost on line power

But after LOW BATTERY is detected there is NO such alert.


Any comments greatly appreciated.

Roger Salisbury
roger at pchelp2u.com.au
75 Mawson Pde 
Chifley Sydney NSW 2036
0296618811 mob 0400339007

Interfacing a Contact-Closure UPS to Mac OS X and Linux
Having acquired some cheap Liebert Powersure Proactive and Powersure Personal UPS boxes, I set about interfacing them to my Mac and Linux machines. In the process I learned a few things about OS X that I didn't know before. 

Both models of UPS have a 9-way D socket on the back with a basic contact-closure signalling arrangement that allows On Battery and Low Battery to be indicated by the closing of relay contacts. The Proactive uses relays and is polarity-independent whereas the Personal uses solid-state switching and is polarity sensitive. It also assigns a remote-shutdown function to pin 6. 

      1 Low Battery (+) 
      2 Not Used 
      3 Not Used 
      4 UPS Off 
      5 UPS Ground 
      6 On Battery (NC)/Remote Shutdown 
      7 Low Battery (-) 
      8 On Battery (COM) (-) 
      9 On Battery (NO) (+) 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.alioth.debian.org/pipermail/nut-upsuser/attachments/20100821/a9696e70/attachment.htm>

More information about the Nut-upsuser mailing list