The data monitor type is chosen when you create a new data monitor. For information on how to create a data monitor, see Creating a Data Monitor.
This monitor is somewhat different than others in that it provides an extra level of abstraction that you can use to simplify the information presented to operators. Sometimes called "indicator lights" or "heads-up displays," these monitors show graphics that translate more complex values into simple, rapidly observable results such as green/amber/red "signal lights" or checkmark/asterisk/exclamation point symbols. "Last State" data monitors could also be called "most recently known state" monitors.
Last State data monitors are built on the information collected by Active Lists. The qualifying events in active lists are identified on the basis of selected key fields such as Source Zone and Source Address (see Data Fields).
Having focused on the events that apply, you then select a field to use as the basis of the values the indicators will simplify. For example, the Priority field has a range of values you could divide into sub-ranges that you choose to translate into good/okay/bad groups.
With a value-range and status-scheme decided, you can map the field values to the status names, and the status names to the visual indicators operators will see.