Specifications

Page 5–10
FOCUS System Manual
Figure 5–7.
Two ARMed APM Loops – Scenario 2.
Scenario 3
This scenario, (Figure 5-8), shows what will occur
if the FOCUS chassis functioning as the common
chassis of a two-loop system is not programmed
as the master. Here, chassis 532 is the
programmed master of the system. If a break
occurs in Loop 2, synchronization slips will occur
in Loop 1 because there will now be two masters.
With a break between chassis 206 and 439, chassis
206 becomes a master, and chassis 386 switches
its synchronization to X2-1 (into the failed loop).
Because Loop 1 is not in APM, chassis 532
remains a master. In this case, chassis 116 is
synched to 532, and the remaining chassis are
synched to 206. You can expect sync slips
throughout Loop 1.
Note that if a break occurs in Loop 1, there should
be no synchronization slips.
Figure 5–8.
Two ARMed APM Loops – Scenario 3.
Scenario 4
This scenario, (Figure 5-9), shows what will
happen if none of the FOCUS chassis in a two-
loop system is programmed as the master. Here,
spur chassis 305 is the programmed master of the
system.
If a break occurs in Loop 2, synchronization slips
occur in Loop 1 because there are now two
masters. With a break between chassis 206 and
439, the 206 chassis becomes a master, and
chassis 386 switches its synchronization to X2-1
(into the failed loop).
Because Loop 1 is not in APM, chassis 246 does
not switch its synchronization into the APM loop.
In this case, chassis 246, 532, and 116 are synched
to chassis 305, and the remaining chassis are
synched to 206. You can expect sync slips
throughout Loop 1.
Note that if a break occurs in Loop 1, there should
be no synchronization slips.
Figure 5–9.
Two ARMed APM Loops – Scenario 4.
5.1.4.10 Using the “Skip Channels”
Feature
The “skip channels” feature is one of your options
when arming an APM loop (see “Arming APM
Loops” earlier in this chapter). It lets you selec-
tively disable the APM rerouting of individual
DS0 channels within the loop. To do so, bring up
the “APM Arm” dialog box and click on the check
box beneath each channel number you want to
skip (i.e., each channel for which you want APM
to be disabled).