Alarm output 2 and the 941 siren board?

[SkyBolt]

I am trying to hookup my siren to output 2 so that Burg and Fire are the corect output sound. Steady for burg, and yelp for fire. So I purchased an ELK-941 output director, thinking this would fix my problem. And well it didn't, the siren and board draw more then output 2 supports so I an trying to use AUX power, but the grounds are isolated and that isn't working.
 
So now I give up and want to start over.
 
Can anyone explain how this is supposed to be done? I can't seem to find anywhere how your suppose to hook up a dual purpose siren.
 
Thanks
Skybolt

 

[jpmargis]

Take a look at the second diagram on the last page of the ELK 941 instructions.  What are you trying to do that is different?  The grounds appear to all be connected together, so what do you mean by "isolated"?

 

[SkyBolt]

The "-" of output 2 is not the same as the "-" of VAux, there is a difference of potential of ~9v. The minus or ground of output 2 isn't a ground at all. It is only a ground when referenced to the "+" of output two. 
 
Anyway, once I put a voltmeter on the output I realized I needed to use the "-" as the alarm output trigger. Because I am using VAux the 12v  or "+" is now the common but still connected to the 12v. I needed to move jumper J3 to "-" trigger instead of "+" trigger and now it's working great.

 

[thill]

1. The industry norm for siren sounds is reverse of what you stated. It's yelp (whoop - whoop) for Burglary and steady for Fire. It also common for the steady of the fire sound to be temporal coded, that is, 3 timed sounds broken by a short silence time and then repeated.
2. When set to produce siren sound (not voltage) the M1 Output 2 produces these exact sounds, so it would actually save you time and trouble to just connect Output 2 to alarm speakers and forget the idea of connecting a separate siren driver and or 941 alarm director.