Grass Valley 8972PX - Manual (Page 20)

20 8972PX — Instruction Manual
Configuration Summary
Switching Summary Tables
To aid in understanding the detailed processing behavior in the various
states of the module inputs, a number of switching summary tables are pro-
vided in the next section. Use these tables along with the following three
basic rules for autonomous switching of inputs to the Program output to
better understand processing behavior:
1. The module always selects the Primary or Secondary inputs (when
valid) over the Alternate input.
2. In the Maintain Primary autonomous mode, the module always selects
the Primary input when it is valid.
3. In the Maintain Stability autonomous mode, the module always selects
the valid input that reduces the amount of switching. If it switches from
the Primary to the Secondary, it will leave the Secondary as the Program
output until the Secondary fails.
Table 1 through Table 5 present a detailed description of the next Program
output/Backup Candidate state by giving each possible case for the current
state of the Program output and the Backup Candidate using the Primary,
Secondary, and Alternate inputs and other configuration factors.
Table 1 through Table 5 include the following:
• Program = Primary/Backup = Secondary Table 1 on page 22
• Program = Secondary/Backup = Primary Table 2 on page 22
• Program = Alternate/Backup = Primary Table 3 on page 23
• Program = Primary/Backup = Alternate Table 4 on page 23
• Program = Secondary/Backup = Alternate Table 5 on page 24
Table 6 on page 25 provides a graphical summary of the various states of
the Program Output. Refer to the explanation of this table in Protect Switch
Summary Table on page 24 .