Because RFL™ and Hubbell® have a policy of continuous product improvement, we reserve the right to change designs and specifications without notice.
2.2.9.5 DESCRIPTION OF A TYPICAL DACS MODULE MAP
Figure 2-9 represents a typical DACS module routing and its active map. Each DACS module has eight bi-
directional ports labeled Port 1 through Port 8. Each port has a DS1 frame, and each frame has 24 DS0 time
slots labeled Time Slot 1 through Time Slot 24. The contents of each time slot, has two numbers separated by a
comma. The first number is the Port number, and the second number is the Time Slot number.
The map shows where the DS0 data is coming from and where it is going to. The position in the map,
which is the DS0 time slot, and its corresponding port num
ber, is where the data is going
to and the
content of that DS0 time slot is where the data is co
m
ing from. This can be better understood by
referring to the following examples.
Example 1: 3,01 under the heading Port 2 is located in time slot 1. This indicates that the data
going to Port 2 time slot 1 came from Port 3 time slot 1.
Example 2: 6,11 under the heading Port 4 is located in time slot 11. This indicates that the data
going to Port 4 time slot 11 came from Port 6 time slot 11.
Example 3: 4,19 under the heading Port 6 is located in time slot 19. This indicates that the data
going to Port 6 time slot 19 came from Port 4 time slot 19.
If a time slot is not configured to pass data, it will be labeled 0,FF.
Note in Figure 2-9 that each port
has two columns, an RX column and a TX column. The RX column cannot be changed by the user.
The TX column can be changed by the user.
2.2.9.6 MAPPING OF A DACS RING
Figure 2-10 shows an example of a fiber optic T1 Loop System consisting of four M-DACS units labeled M-
DACS A, M-DACS B, M-DACS C, and M-DACS D. In this example no failures are detected in any of the
network paths. Therefore, each DACS module in the M-DACS unit is using its own map 0. The outer heavy
line represents the primary path and the inner light line represents the backup path.
Figure 2-11 shows the same T1 Loop System with a break in the network path between M-DACS A and M-
DACS B. The break can be in any
one of the prim
ary path fiber optic cables between M-DACS A and M-
DACS B. Let’s assume in this example that the break occurred between M-DACS A port 1 and M-DACS B
port 4. This will be detected by M-DACS A and M-DACS B and will cause M-DACS A to switch to map 1 and
M-DACS B to switch to map 4. M-DACS C and D will be unaffected and therefore will still use map 0. The
remapping will cause data to be re-routed away from all direct connections between M-DACS A and M-DACS
B, and will now follow the backup path as shown by the heavy line in the Figure 2-11.
Table 2-2 shows map 0 for M-DACS A, Table 2-3 shows map 1 for M-DACS A.
Table 2-4 shows map 0 for M-DACS B, Table 2-5 shows map 4 for M-DACS B.
Table 2-6 shows map 0 for M-DACS C.
Table 2-7 shows map 0 for M-DACS D.
2.2.9.7 MAP SELECT CRITERIA
When a DACS module detects a port failure, the failed port switches from Map 0 to an alternate map
(Map 1 to Map 7). The map switching takes place in accordance with Map Select Criteria, which must
be programmed by the user using NMS.
M-DACS-T1 RFL Electronics Inc.
October 16, 2012 2-13 (973) 334-3100
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