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Making Measurements
Using Markers
Using Markers The key displays a movable active marker on the screen and provides access to a
series of menus to control up to five display markers for each channel. Markers are used to
obtain numerical readings of measured values. They also provide capabilities for reducing
measurement time by changing stimulus parameters, searching the trace for specific
values, or statistically analyzing part or all of the trace.
Markers have a stimulus value (the x-axis value in a Cartesian format) and a response
value (the y-axis value in a Cartesian format). In polar format, the second part of a
complex data pair is also provided as an auxiliary response value. In Smith chart format,
the real and imaginary rectangle are both displayed, and the effective capacitance or
inductance of the imaginary part is also displayed. When a marker is activated and no
other function is active, its stimulus value is displayed in the active entry area and can be
controlled with the knob, the step keys, or the numeric keypad. The active marker can be
moved to any point on the trace, and its response and stimulus values are displayed at the
top right corner of the graticule for each displayed channel, in units appropriate to the
display format. The displayed marker response values are valid even when the measured
data is above or below the range displayed on the graticule.
• If you activate both data and memory traces, the marker values apply to the data trace.
• If you activate only the memory trace, the marker values apply to the memory trace.
• If you activate a memory math function (data/memory or data-memory), the marker
values apply to the trace resulting from the memory math function.
Marker values are normally continuous: that is, they are interpolated between measured
points. They can also be set to read only discrete measured points. Markers normally have
the same stimulus values for all channels, or they can be uncoupled so that each channel
has independent markers, regardless of whether stimulus values are coupled or dual
channel display is on.
To Use Continuous and Discrete Markers
The analyzer can either place markers on discrete measured points, or move the markers
continuously along a trace by interpolating the data value between measured points.
• Press and select one of the following choices:
— Choose if you want the analyzer to place markers at
any point on the trace, by interpolating between measured points. This default mode
allows you to conveniently obtain round numbers for the stimulus value.
— Choose if you want the analyzer to place markers only on
measured trace points determined by the stimulus settings. This may be the best
mode to use with automated testing, using a computer or test sequencing because
the analyzer does not interpolate between measured points.
Marker
Marker Fctn
MARKER MODE MENU
MARKERS: CONTINUOUS
MARKERS: DISCRETE