DECrepeater 350 Service Guide

This document is the Service Guide for the DECrepeater 350 (DETPR), a Digital Equipment Corporation product. It provides a comprehensive functional overview, configuration guidelines, troubleshooting information, and detailed specifications for the device.

Key aspects covered include:

1. DECrepeater 350 Overview: Describes the DETPR as an AC-powered signal repeater with eight twisted-pair ports and one Attachment Unit Interface (AUI) port. It functions as a common data bus, connecting multiple node devices to an Ethernet backbone and extending the physical system topology by restoring signal amplitude and timing. It is not an Ethernet-addressable unit.
2. Functional Description: Details how the DETPR processes data, including buffering, preamble restoration, and data transmission. It explains crucial features like collision enforcement, which jams other ports upon collision detection, and circuit segmentation, which isolates faulty ports to maintain network availability and automatically restores them upon error-free operation.
3. Configuration Rules: Provides guidelines and constraints for installing and using the DETPR in a multisegment Twisted-Pair Ethernet environment. It specifies limitations on the number of repeaters, details for connecting station equipment, guidelines for DELNI/DETPR pyramids, and explicit requirements for twisted-pair cabling (e.g., maximum length of 100 meters, wire type, impedance) and environmental restrictions.
4. Troubleshooting: Offers extensive diagnostic tools and procedures to isolate problems with the DETPR unit, its cabling, or connected station equipment. This section covers internal power-up tests, external self-tests, and specific tests for station and Ethernet connections, including a crossover test. It also explains how to interpret the DETPR's control panel LED indicators to diagnose various fault conditions and cable issues.
5. Specifications: Lists detailed physical dimensions (for desktop and rackmount versions), electrical requirements (AC and DC power), environmental operating conditions (temperature, altitude, humidity), relevant part numbers for accessories and cables, and precise pinouts for both the 8-pin modular jack (MJ) and 15-pin D-subminiature connectors.

In essence, the document serves as a complete technical manual for anyone installing, configuring, or troubleshooting the DECrepeater 350.