Zhone Technologies IMACS-200 manual Setting the System Clock Source

Other CPU Settings IMACS-200 General Features

4.4.1System Clock Source

Figure 4-8.Setting the System Clock Source

The IMACS-200 can be set to source to an incoming timing source from the WAN, the HSU, the optional OWAN, or on its internal clock. Figure 4-8shows this setting from the CPU Clock screen. Choosing one of the three choices and saving the choice will force the system to time off of that source.

The crafts person can choose a different source for both the Primary and Secondary inputs, and the current clock field will update to the highest-order clock available. The primary clock is always the systems first choice, followed by the Secondary clock and then finally the shelf will internally time. For example, should the primary timing source fail, the system will automatically switch to the secondary source. Should the primary timing source recover, then the system will automatically switch back to the primary timing source. Should both the primary and secondary sources fail, then the IMACS-200 will revert to internally timed. Loss of the secondary timing source while the primary source is still available will have no impact to the system operation.

4-14 General Features