Just trying to make the alarm stop complaining now and then.  It gets annoying. 
 One way it can detect if it has a phone line is to see the on hook voltage.  
Use to be that fax machines would hang up if the line voltage went too low 
indicating someone else had picked up the line.  But low on hook voltage will 
fool these systems into thinking the line is busy.  

From: Josh Reynolds 
Sent: Friday, August 04, 2017 5:48 PM
To: [email protected] 
Subject: Re: [AFMUG] OT ATA

It sounds like he's asking for a very specific tip/ring/onhook voltage to be 
compatible with the panel.

On Aug 4, 2017 6:14 PM, "George Skorup" <[email protected]> wrote:

  Don't they kinda all have to provide on-hook voltage, at perhaps limited 
current, for simple stuff like CID history displays..? My folks have old timey 
phones at home with telco powered caller ID displays. No wall warts. Of course 
they are still on Ma Bell, too.


  On 8/4/2017 6:07 PM, [email protected] wrote:

    Nice, thanks.  

    From: Josh Reynolds 
    Sent: Friday, August 4, 2017 4:58 PM
    To: [email protected] 
    Subject: Re: [AFMUG] OT ATA

    Found the following for a Cisco SPA112 


    On Aug 4, 2017 5:44 PM, "Josh Reynolds" <[email protected]> wrote:

      I'd start checking the docs on those Cisco SPA's

      On Aug 4, 2017 12:29 PM, <[email protected]> wrote:

        Anyone know of an ATA that puts out 48 volts open circuit on the phone 
line?  I have a cranky fire alarm panel.  

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