Keying Of Media Interface Connectors - Cabletron Systems 3F00-01 User Manual

Chapter 2: Connecting to the Network

2.3 KEYING OF MEDIA INTERFACE CONNECTORS

Optical fiber connections are made using a Media Interface Connector
(MIC). A MIC consists of two parts:
• The MIC plug, which terminates the optical fiber cable
• The MIC receptacle, which is on the FDDI node or station
To ensure that the MIC plugs and MIC port receptacles are correctly
mated, FDDI standards state that different types of MIC plugs and
receptacles must be keyed as one of the following:
• A (primary in/secondary out)
• B (secondary in/primary out)
• M (master)
• S (slave)
Matching slots are used to identify the MIC plugs and receptacles of the
same type. The MIC key slot must be the correct type for the MIC
receptacle (A, B, M, or S) and must be properly aligned, or you will not
be able to connect the MIC.
The key slot may be permanently molded into the MIC, although many
vendors supply one MIC that can be alternately keyed as an A, B, M, or S
connector. Several MIC vendors provide an attached dust cover that fits
over the end of the MIC plug and contains three small plastic pieces
which may be fitted into the MIC to provide the appropriate keying.
The small movable pieces used to key MIC connectors are usually marked
(A, B, M, or S) and are often color coded (usually: red=MIC A, blue or
yellow = MIC B). However, since color coding is not specified in the
FDDI standards, there is no standard color coding scheme.
Page 2-8 FDDI Dual-Attached Intelligent Module User's Guide