INSTALLING THE TRMIM-10R
Page 3-4
3.3 ATTACHING CABLES TO THE TRMIM-10R
Prior to connecting cables, check that the pinout and maximum cable
lengths throughout the system conform to the requirements described
in Chapter 2, Installation Requirements/Specifications.
The trunk coupling unit (TCU) and Ring-In/Ring-Out trunk ports of
the TRMIM-10R are not sensitive to signal polarity. If the (+) and (-)
lines within a pair are reversed, the network will still function
properly due to the differential Manchester encoding. Operating in
this condition is not recommended. When discovered, the cable
connections should be corrected according to the information provided
in Chapter 2, Installation Requirements/Specifications.
3.3.1 Connecting Lobe Cabling
The physical lobe cable (see Figure 3-3) between the TRMIM-10R and
a token ring station consists of two pairs of wire: a transmit signal
pair (TX+, TX-) and a receive signal pair (RX+, RX-). The transmit
pair from the TRMIM-10R connects to the receive pair of the station
and the receive pair from the TRMIM-10R connects to the transmit
pair of the station. For example, TX+ from the TRMIM-10R connects
to RX+ of the station and RX+ from the TRMIM-10R connects to TX+
on the station. This provides the necessary Crossover or Null Modem
Effect.
Figure 3-3. STP Connections
TX+
TX–
RX+
RX–
TX+
TX–
RX+
RX–
1
6
5
9
Trunk Coupling Port
Token Ring Station
Lobe Cable
GREEN
BLACK
RED
ORANGE
DB-9 Connectors
1
6
5
9
