DECserver 900GM and 900GMx

This document is the "DECserver 900GM and 900GMx Installation" manual, published in February 1997. It provides comprehensive instructions and technical details for installing and configuring these network access server modules.

Key Information Covered:

• Product Description: The DECserver 900GM and 900GMx are network access servers designed to connect asynchronous devices (like terminals, printers, modems, or PCs) to an Ethernet Local Area Network (LAN). The 900GM supports up to 16 full or 32 partial modem control ports, while the 900GMx supports up to 8 full or 16 partial ports. Both can operate within a DEChub 900 MultiSwitch (with hot-swap capability) or as a standalone unit with a DEChub ONE docking station.
• Features: Includes ThinWire 10base2 access, backplane LAN access, automatic self-test, in-band Simple Network Management Protocol (SNMP) management with built-in Management Information Bases (MIBs), and Graphical User Interface (GUI) manageability via Digital's HUBwatch Network Management Station (NMS).
• Installation & Removal: Step-by-step procedures for seating the module into a DEChub 900 MultiSwitch (including power verification and hot-swap notes), installing Flash RAM cards, and connecting port cables (up to four 68-pin D-connectors). Instructions for safely removing the module are also provided.
• Troubleshooting: Detailed sections explain the meaning of LED states (Power, Module OK, Network OK, Network Activity) and seven-segment display codes for diagnosing problems during power-up and operation, offering probable causes and corrective actions for various error conditions.
• Cabling & Compatibility: Provides extensive information on maximum cable lengths for different line protocols (EIA-432-A/V1.0, DEC 423, EIA-232-E/V.28) and baud rates. It includes detailed connector pin assignments and wiring diagrams for various cable types (e.g., 68-pin bulk to 50-pin Telco, 25-pin DB Octopus, 8-pin MP Octopus) to support full or partial modem control connections. A "Cable Compatibility" section lists specific adapters and cables for connecting modems, PCs, and terminals, and a 68-pin to 8-pin MJ loopback connector for testing.
• Product Specifications: Outlines physical dimensions, weight, environmental operating limits (temperature, humidity, altitude), power consumption for both GM and GMx models, and lists regulatory certifications (CE, CSA, FCC, TÜV, UL, VCCI). Acoustical specifications (noise levels) are also provided.