Data General AViiON 5000 Series, Customer Documentation

Page: 133 / 210

Connecting External Devices to VME Option Boards
4-33
014–001867
Connecting a VTRC Controller to a
Token Ring LAN
A token ring local area network (LAN) can incorporate several devices that
communicate over a common system of cable and Trunk Access Units (TAUs). (Some
networks refer to their access units as Media Access Units, or MAUs.) This section
describes how to connect the first cable between your computer’s VTRC controller
and a token ring LAN.
NOTE: For information on setting up the cables and TAUs on your token ring
LAN, refer to DG/Token Ring Local Area Network Installation Guide.
Figure 4–40 shows the location of the token ring connector on a VTRC board
installed in a deskside system.
Deskside AViiON computer – rear view
VTRC connector (female)
Figure 4–40 VTRC LAN Connector
A lobe cable from the VTRC connector at the rear of your computer to a trunk access
unit attaches the controller to a token ring LAN. The lobe may consist of a single
cable connecting directly, or a series of cables which indirectly connect the VTRC to
a TAU.
Shielded twisted pair lobe cables have a 9-pin D connector on one end, and an
IEEE 802.5 compliant data connector on the other. Indirect connections often use
unshielded telephone cable with an RJ11 connector that can attach to a wall outlet
or data connector. Unshielded twisted pair cables include a filter on the 9-pin
connector end to diminish electronic emissions that might impair data transmission.
Refer to DG/Token Ring Local Area Network Installation Guide for a detailed
explanation of LAN cabling.