Each time the capture data changes, the following happens:
•the plug-in's SetInitItem() is called multiple times to set some globals
•the plug-in's SetCfgItem() is called multiple times to configure the plug-in with the user's settings for THIS signal
•the plug-in's StartOfData() is called to allow final preparations
•Data events from the pre-processor are streamed to the plug-in's Parse() routine.
•Parse() uses calls to various Data Output Routines to stream back field information.
•When all of the events have been sent, the plug-in's EndOfData() is called.
•If multiple signals are using the same plug-in, the above sequence will be repeated for each signal in turn (using that signal's specific configuration and the resulting event stream)
