Phone Left Off - Hook Sound

[ARAR]

I have a phone connected to the OBI / 100 which gets knocked off the hook many times by my pets and kids.  I cannot move the phone location for many reasons.

With the phone company, if a phone was left off the hook and not used for a few minutes, a loud sound would occur in the ear piece to to notify people around that the phone was off the hook.

Is a similar feature available with the OBI / 100?  How do I set that up?

[drgeoff]

No, such a feature is not present in Obi devices.

[ianobi]

It's known as "Howling Tone". It does exist on the OBi1xx models, but only sounds for 10 seconds after around 20 seconds of Dial Tone and 10 seconds of a SIT Tone. This results in silence after around 40 seconds.

In theory you can make any tone play indefinitely, but when I tried that with Howling Tone the OBi110 I'm testing with simply reverts to an announcement - not great for your purposes. However, it is possible to extend the period of Howling Tone. I tried 60 seconds, which works fine - I have not tested to see just how long you can make it.

Find Howling Tone in the Tone Profile your Phone Port uses (Tone Profile A is the default). You should see this:

480+3,620+3;10;(.125+.125)

10 is the duration of the tone in seconds. Change to this:

480+3,620+3;60;(.125+.125)

The tone now plays for 60 seconds.

Make changes via the OBi Expert Configuration pages. From your OBi Dashboard, click on your OBi number and follow the prompts to get there. To change a value uncheck both boxes to the right of the value and leave them unchecked. After changing the value, press submit at the bottom of the page and wait a few minutes for the OBi to reboot.

[SteveInWA]

The howling tone uses a lot of power to drive the amplifier loud enough to blast that sound at levels loud enough to hear through the phone's earpiece vs. a regular speaker.  I'd be concerned that making it play that long might overheat the SLIC IC in the OBi, which doesn't have a heat sink.  But hey, it might be a good way to kill your OBi 100 so you can upgrade.   

[ianobi]

The howling tone uses a lot of power to drive the amplifier loud enough to blast that sound at levels loud enough to hear through the phone's earpiece vs. a regular speaker.

Fair point, although we don't really know what the SLIC can cope with in practice. The OP could experiment with volume to see if the tone can be sufficiently annoying at lower levels. Looking at this code:

480+3,620+3;60;(.125+.125)

3 is the volume level in dB. Try values like -1 or -5 etc  to try lower levels. Both instances of 3 need to be changed to the new volume.

We could get really creative and change the frequencies (480Hz and 620Hz) to something that really annoys the pets - cats/dogs - then they could make sufficient noise to let you know the phone is off hook   

[SteveInWA]

I'm always amused by people who try to solve human (or animal, in this case) problems with OBi settings.

There is no way to know how long the tone could sound before overheating the IC.  It would take lab testing.  The SLIC has a continuous power dissipation rating of 1.3W @ 85 degrees C.  There is no published information as to how this value would need to be de-rated when the component is mounted inside a case, with no fan nor heatsink.

So, knock yourself out, and don't come back here complaining if your OBi dies.

[azrobert]

The OBi has a feature that will place a call when the phone is off-hook for a specified number of seconds without dialing a number. Maybe direct the call to your cell phone? The person receiving the call can tell what's happening by the CallerID. You could do the same if the pet/child dials an invalid number. Let me know if you're interested and I'll show you how.

[Bonre]

The Performer 8 has a feature that will place a call when the phone is off-hook for a specified number of seconds without dialing a number. Maybe direct the call to your cell phone? The person receiving the call can tell what's happening by the CallerID. You could do the same if the pet/child dials an invalid number. Let me know if you're interested and I'll show you how.

This sounds like a good idea though even if it's not possible.