Media Links MD8000 Series, Руководство по эксплуатации

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MD8000 Rev. H MD8000 Series Transport System Summary 2.35
Switching Between ACT and STB Operation
The SWCNT board in the Stand-by state (STB) state continues to watch the condition of the
Active SWCNT (ACT) board. When detecting an abnormal condition of the ACT board, the
STB board sets the ACT board to STB and activates itself to the Active state. Table 2-14
shows the cause and effect relationship between ACT/STB switching.
State Transition
Figure 2-31 and 2-32 show the state transition diagrams of SWCNT #1 and #2.
Figure 2-31: SWCNT #1 State Transition
Table 2-14: Cause/Effect of ACT/STB Switching
Item Cause Effect
1 Restart by WDT The ACT transitions to Down state and terminates the
ACT state autonomously.
2
L2SW Abnormal Same as above
3
SWCNT Hardware Failure Unpredictable
4
ACT removed from the
chassis The STB detects the removal and transitions to ACT
state.
5
Life check Abnormal Detecting the abnormality, the STB resets and terminates
the ACT.