Specifications

System Overview 27
• Digitized speech recording and playback, including full bandwidth and
low-bit-rate voice encoding
• Control of the TLI that includes DTMF tone signal detection, call
progress detection, and outward pulse and DTMF dialing
2.1.2 TLI Assembly
The TLI assembly connects the DTC04 module to the telephone network.
The TLI has the following capabilities:
• Standard tip and ring connection over analog telephone lines with
USOC RJ11 service
• Incoming call (ring) detection
• Line current interruption (wink) detection
• Outward pulse dial and switchhook flash
The TLI meets the standards of FCC Part 68—U.S. Telephonics and
Canadian DOC Telecommunications.
2.2 Physical Description
This section describes the DTC04 module and TLI assembly hardware.
2.2.1 DTC04 Module
The DTC04 voice module is a quad-height, 25.8 x 20.6 centimeter (10.5 x
8.4 inch) Q-bus module. It contains all the voice processing circuitry for
the DECvoice system. The DTC04 module plugs into a Digital MicroVAX
II Q-bus processor. The module connects to the TLI assembly through a
20-pin ribbon cable connector.
2.2.2 TLI Assembly
The TLI assembly consists of a two-card stack and a metal plate. The
circuitry in the assembly is logically divided in half so that each TLI can
support two DECvoice DTC04 modules. One card contains all the TLI
circuitry. The other card contains the circuitry to communicate with the
DTC04 voice module. The assembly measures 13.3 cm x 8.6 cm x 3.18
cm (5.25 x 3.4 x 1.25 inches). The assembly can connect to two telephone
lines through two separate AT&T RJ11 connectors. The assembly can
connect to two DTC04 voice modules through two separate 20-pin ribbon
cable connectors.