Nellcor N-200 Operator's Manual page 46

Guide to Operation
The following automatic markers appear on ThinkJet trend
graphs:
Occurrence
Alarm-limit event
User-defined event
Power turned off
Pulse signal is lost
Clock is reset
Signal is acquired
Whenever an A marker appears, the trend graph ends and a
new one begins. If less than 5 minutes elapse, no A marker is
printed; instead, the period during which the power was off or
the signal was lost is represented on the trend graph by
missing data points.
Data is plotted using a fixed time scale on the horizontal axis.
The time and date of data acquisition are printed below that
axis.
Each event is marked by a tick on the horizontal axis.
Identifiers for the events appear in up to four additional lines
of text that are printed below the time and date lines. Each
identifier consists of a letter that indicates the type of event
and its onset time (for example, L3:47 indicates an alarm-limit
event that began at 3:47 a.m.). As many identifiers as possible
are packed into these four lines of text, with each identifier
approximately aligned with its tick mark on the axis.
If events are very frequent and too closely spaced so that all
four lines of text are filled, some identifiers do not print;
however, all events are still identified by tick marks. If more
than 60 events occurred during the period of time covered by
the trend memory, only the last 60 will be identified by type of
event and time of occurrence. The remaining events are
identified only by tick marks on the horizontal axis.
Additionally, there is a limit of 60 minutes of data that can be
stored in event memory, regardless of the number of events.
40
Marker
L
E
P
S
C
A