You can use the Historical tab in Analyze Modem View to view the status history of a single cable modem and compare that history with other historical parameters.
Drag and drop the parameter CM Status from the Historical>Parameters>CM tab into the graph area. The cable modem status history is displayed for the selected cable modem.
Cable modem status values shown map to the regStatus MIB values described in Mapping of MIB regStatus value to modem status.
In this view, you can compare the status of a modem over time with values for other parameters occurring in the same period.