Convergent Voice Module

From: R. Stricklin <>
Date: Tue May 5 03:44:20 1998

I promised Sam I'd look this up a long time ago. I had some trouble with
the phone lines, though, which made it impossible to use the modem.

But here it is. I seem to have a preliminary version of the 'Voice Module'
manual, although I did not get the module itself with the machine.

The manual goes into a lot of detail: theory of operation, external
interfaces, architecture... schematics...

I'll quote from the overview:



The Voice Processor Module, shown in Figure 1-1, provides a fully
integrated voice and data interface between a workstation and the switched
telephone netowrk or commonly used private automatic branche exchange
(PABX) system (supporting Tip and Ring connection). When used with a
digital PABX system, all signals and transmission between the Voice
Processor Module and the PABX occur via analog techniques.

The Voice Processor Module is an X-Bus module containing two
printed-circuit boards. The first board contains a Bell 212A-compatible

The second board contains the following:

 * modular jacks for two telephone line interfaces (FCC, part 68, registered)
 * additional modular jack (FCC, part 68, registered) that allows
   connection to any standard voice unit (telephone set)
 * analog crosspoint switch allowing any device to connect to either line
   under software control
 * Dual-Tone Multifrequency (DTMF) touch-tone auto-dialer
 * DTMF touch-tone decoder that permits numeric data entry via remote
   voice unit touch pad
 * call progress tone detector
 * voice amplifier
 * Adaptive Pulse Code Modulation (ADPCM) CODEC (Coder/Decoder) for
   support of digitized voice communications at speeds far less than the
   normal 64Kbps
 * 8051 microprocessor to control all module activities

(...excepts from following specifications...)

Modem board is originate/answer, full-duplex. Supports 212A and Bell

DTMF generator generates all 16 DTMF digits, may be programmed to transmit
various key sequences, and can generate single tones.

CODEC and ADPCM technique allows recording/playback of digitized voice
information at 6-kHz (24Kbps) or 8-kHz (32Kbps) rates.

Software support is provided by CT-MAIL, CT-Net, and "Operator" software,
which is specifically tailored for the Voice Module as follows:

 * Telephone directory management, which has the ability to add, delete,
   modify, and look up entries in a disk-based telephone directory, and
   automatically establish calls using the information in the directory.
   Menus provide assistance in accessing special functions used by PABXs.
 * Voice digitization, which allows the operator to use the CODEC to
   record and play back calls or messages. This capability enhances
   CT-MAIL, where it is used for voice annotation of written documents, as
   well as the inclusion of voice attatchments to textual mail.
 * Telephone answering, which allows an unattended system to automatically
   answer the telephone and perform a variety of user-selectable
   operations ranging from simple messatge playback/recording to input of
   numeric data from a telephone touch-tone pad.

There you have it. All typos are my responsibility.

Received on Tue May 05 1998 - 03:44:20 BST

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:31:11 BST