INSTALLATION
Page 3-6
The LED activity presented above represents a power-up with no cables
connected to the TRXMIM. See Section 4.2, LANVIEW LED SIGNALS,
to determine appropriate activity for other start-up conditions.
Because port assignments can be made only by a management
module, the TRXMIM goes through a bypass period at each
start-up to provide a time-window of opportunity during which a
management module may announce its intention to make these
assignments. During this start-up period, the TRXMIM holds itself
in full bypass mode by setting all ports to loop-back to prevent
them from connecting to any ring. After the start-up procedure is
complete--either the TRXMIM has been programmed by
management or has gone to default mode--the TRXMIM returns to
normal operations.
3.2.5 Connecting Lobe Cabling
The physical lobe connection from the TRXMIM to the Token
Ring station does not require the use of a crossover cable.
To
provide the necessary signal crossover or null modem effect, the
TCU and Token Ring station connectors are wired so that the
transmit pair from the TRXMIM connects to the receive pair in the
station and the receive pair from the TRXMIM connects to the
transmit pair in the station. Table 3-1 provides a cross-reference of
pinouts for connections that may be encountered along the length
of lobe cabling.
Table 2-1. Lobe Cabling Connector / Signal Pinout Cross-reference
TX+
TX–
RX+
RX–
RJ-11 6-pin
modular connector
5
2
3
4
RJ-45 8-pin
modular connector
6
3
4
5
Data Connector
(MIC) genderless
O
B
R
G
DB-9 9-pin
D-shell connector
9
5
1
6
