DECvoice-T1

This document, "DECvoice-T1 Hardware Installation" (Order Number: EK-DVMILS-IN. C01), by Digital Equipment Corporation (1991, 1995), serves as a hardware installation and configuration guide for the DECvoice-T1 system. It is intended for Digital Customer Service personnel and approved self-maintenance users, though it notes that factory preconfigured systems do not require these procedures and recommends professional installation.

The DECvoice-T1 system integrates hardware and software to provide voice application capabilities for MicroVAX computers. Its primary hardware components are:

• M3136 T1 Telephony Module: The master module for routing Pulse Code Modulation (PCM) data. It connects to up to three external T1 lines (via Channel Service Units/CSU for Public Switched Telephone Network or channel banks) and drives three internal Time Division Multiplex (TDM) Highways for M3135 modules, featuring non-blocking switching.
• M3135 Voice Module: The data processing module that connects to the TDM Highways. It handles various voice functions, including digitized speech recording and playback (supporting ADPCM), text-to-speech conversion, DTMF/MF tone detection and dialing, and speaker-independent/dependent voice recognition.

The manual details critical installation steps such as:

1. System Configuration Checks: Ensuring power and bus load limits are not exceeded.
2. Unpacking: With a strong emphasis on electrostatic discharge (ESD) precautions.
3. Module Configuration: Setting unique Control and Status Register (CSR) addresses on each module using switchpacks, which is crucial for the operating system to correctly recognize and configure devices.
4. Module Placement and Cabling: Guidelines for proper slot order, installation of modules and gap fillers (to control electromagnetic interference), and the daisy-chaining of TDM Highways between modules and to terminators.

It also provides a technical overview of the modules' functional blocks, including their processors, memory, and Q-bus interfaces. The document includes diagnostic procedures using the MicroVAX Diagnostic Monitor (MDM) and a comprehensive troubleshooting section to address common issues like modules not being visible, system hangs, or T1 line alarms. Finally, it outlines important telephonics and regulatory information, including FCC and Canadian Department of Communications (DOC) compliance requirements for T1 service.