- Enables or disables clock fallback on the board. When set to YES, this keyword specifies whether or not the board automatically switches between the two clock timing references specified by the Clocking.HBus.ClockSource and Clocking.HBus.FallBackClockSource
keywords. The Clocking.HBus.AutoFallBack keyword applies for all modes specified by the Clocking.HBus.ClockMode keyword.
- The fallback timing reference clock is selected by the Clocking.HBus.FallBackClockSource
keyword. Both of the physical timing references specified by the Clocking.HBus.ClockSource and Clocking.HBus.FallBackClockSource keywords must be present and not in alarm when the board's clocking is set up.
- NO indicates that the system should not fallback to the backup timing reference.
- Specify the primary clock and fallback clock with the Clocking.HBus.ClockSource and Clocking.HBus.FallBackClockSource
keywords.
- If the board is configured as the primary master or in StandAlone mode, this keyword allows the board to switch to the secondary timing reference when the first source goes into an alarm state. If the primary source returns, the board's timing reference switches back to the primary source. The showclks utility program can be used to determine what timing reference the board is actively using.
- If the board is configured as the primary clock master and both timing references fail, the board reconfigures itself to become a slave to the secondary H.110 timing reference.
- For an AG board configured as a secondary clock master or as a clock slave, this keyword allows the board to switch to an alternative timing reference when the first source goes into an alarm state. The board does not return to the first timing reference if it recovers. The host application must perform any further clock configuration operations.
- For more information about clock fallback, refer to the Switching Service Developer's Reference Manual.
Note: If you want to support clock fallback on an AG board, refer to the NMS web site (www.nmss.com) for application notes and other updates.
(Page 8 of 80 in this chapter) Version