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Operating Concepts
Limit Line Operation
If limit lines are on, they are plotted with the data on a plot. If limit testing is on, the PASS
or FAIL message is plotted, and the failing portions of the trace that are a different color on
the display are also a different color on the plot. If limits are specified, they are saved in
memory with an instrument state.
Edit Limits Menu
This menu allows you to specify limits for limit lines or limit testing, and presents a table
of limit values on the display. Limits are de fined in seg ments. Each segment is a portion of
the stimulus span. Up to 22 limit segments can be specified for each channel. The limit
segments do not have to be entered in any particular order: the analyzer automatically
sorts them and lists them on the display in increasing order of start stimulus value.
For each segment, the table lists the segment number, the starting stimulus value, upper
limit, lower limit, and limit type. The ending stimulus value is the start value of the next
segment, or a segment can be terminated with a single point segment. You can enter limit
values as upper and lower limits or delta limits and middle value. As new limit segments
are defined, the tabular listing is updated. If limit lines are switched on, they are shown on
the display.
If no limits have been defined, the table of limit values shows the notation EMPTY. Limit
segments are added to the table using the softkey or edited with the softkey,
as previously described. The last segment on the list is followed by the notation END.
Edit Segment Menu
This menu sets the values of the individual limit segments. The segment to be modified, or
a default segment, is selected in the edit limits menu. The stimulus value can be set with
the controls in the entry block or with a marker (the marker is activated automatically
when this menu is presented). The limit values can be defined as upper and lower limits , or
delta limits and middle value. Both an u p p er limit and a lower limit (or delta lim i ts ) must
be defined: if only one limit is required for a particular measurement, force the other out of
range (for example +500 dB or −500 dB).
As new values are entered, the tabular listing of limit values is updated.
Segments do not have to be listed in any particular order: the analyzer sorts them
automatically in increasing order of start stimulus value when the key in the edit
limits menu is pressed. However, the easies t w a y to enter a set of limits is to start with the
lowest stimulus value and define the segments from left to right of the display, with limit
lines turned on as a visual check.
Phase limit values can be specified between +500° and −500°. Limit values above +180°
and below −180° are mapped into the range of −180° to +180° to correspond with the range
of phase data values.
Offset Limits Menu
This menu allows the complete limit set to be offset in either stimulus value or amplitude
value. This is useful for changing the limits to correspond with a change in the test setup,
or for device specifications that differ in stimulus or amplitude. It can also be used to move
the limit lines away from the data trace temporarily for visual ex am ination of trace detail.
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EDIT
DONE