DEC FDDIcontroller 400 Installation & Problem Solving

This document is an installation and problem-solving manual for the DEC FDDIcontroller 400, also known as DEMFA. Published by Digital Equipment Corporation in October 1991, it is intended for field personnel responsible for installing and servicing the unit.

The manual describes how to install, verify, and troubleshoot the DEMFA, which functions as a high-speed Fiber Distributed Data Interface (FDDI) controller, connecting XMI bus-based VAX 6000 and VAX 9000 systems to FDDI token ring networks via a DECconcentrator 500 unit.

Key components of the DEMFA include the T2027 module, H3063 bulkhead, and an internal adapter cable, with status indicated by LEDs on the module and bulkhead.

The guide covers:

• Product overview and specifications (electrical, environmental, cabling distances).
• Pre-installation preparation, including checking shipment contents and a site verification checklist.
• Step-by-step hardware installation procedures for the T2027 module, H3063 bulkhead, and internal adapter cable.
• Hardware verification methods, including initial power-up diagnostics and interpreting LED status.
• Troubleshooting methodologies, tips, and tools (e.g., FDDI loopback connector, SDU optical power meter kit), along with diagnostic flowcharts.
• Detailed procedures for replacing Field Replaceable Units (FRUs).
• Appendices providing information on line counters, using the System Error Log Formatter (ERF), and using the System Dump Analyzer (SDA) (noted as for Digital Field Service personnel only).

The document also includes extensive safety warnings and cautions regarding power and electrostatic discharge (ESD) precautions during installation and service.