REQUIREMENTS/SPECIFICATIONS
Page 2-6
When a TRMIM-20R is installed, the ring sequence starts at the
externally accessible Ring-In port. If the concentrator is detached (by
software, incompatible ring speed or empty adjacent slots) from other
token ring boards, the ring sequence is restricted to the TRMIM-20R
and goes from the Ring-In port to each of the TCU ports, in ascending
port number order, and then out the Ring-Out port.
When multiple token ring boards are installed in consecutive slots
and attached via the FNB, the sequence is in ascending slot number
order. When a concentrator, such as the TRMIM-20R is attached via
the FNB to other token ring boards, the ring sequence begins at the
Ring-In port of the concentrator and is first routed out, via the FNB,
to the next (higher slot number) token ring board on the bus. An
empty slot or non-token ring board causes the FNB trunk connection
to loop back to the first token ring board in the sequence and
continues to thread through the TCU ports and token ring boards
until it returns to the concentrator. There, it threads through the
TCU ports and finally to the Ring-Out port.
Example: TRMIM-22 in slot 1 with ports 2, 5, 8, & 12 in use.
TRMIM-20R in slot 2 with ports 1, 2, 3, 5, and 6 in use.
TRMIM-12 in slot 3 with ports 1, 5, 7, 11, & 12 in use.
An FNB is installed in the MMAC.
All three boards are attached via the FNB.
The ring sequence for this example is from Slot 2, Ring-In port to the
FNB and Slot 3, ports 1, 5, 7, 11, 12, via the FNB to Slot 1 ports 2, 5,
8, 12; then, returning to Slot 2 ports 1, 2, 3, 5, and 6, then out the
Ring-Out port of the TRMIM-20R.
2.2.3 Connector Types
Trunk Coupling Unit Ports - Ten Female RJ-45 connectors are
located on the front panel of the TRMIM-20R. They are labeled 1
through 10. Figure 2-1 shows the pin layout and signal connections
for these connectors.