Alcatel-Lucent 8038 digital UA Link

[Askjerry]

I have a project with a 911 service center. The Centracom Consoles have a connection for "PHONE" that basically breaks down to the following...

• AUDIO +
  AUDIO -
  MIC +
  MIC -
  OFF Hook
  Ground

The issue that I have is that the 8038 phone, as I understand it... does not have a simple ON / OFF indicator for the OFF-HOOK condition.
I presume that the Digital UA Link on pins 3 and 4 of the RJ12 connector is a serial signal used to send this (and likely other data) out of the phone.

Is there a device I can purchase that simply decodes this and gives me an OFF-HOOK condition?

Or...

Does someone have a method to decode this signal?

• A circuit?
  Arduino code?
  A device?
  Protocol Datasheet?
  Anyone ? Anyone?

Flying to customer today... any help appreciated!!!!

Thanks,
Jerry