Agilent Technologies - page 182

182 Chapter 3
Instrument Functions: M - O
Marker
Instrument Functions: M - O
There are four conditions that can occur when Delta Pair mode is selected.
•If marker mode is Off, the delta marker and reference marker are placed at the center of
the display.
•If marker mode is Normal, the delta marker and reference marker are placed at the
current marker position on the trace.
•IfthemarkermodeisDelta, the current marker position remains unchanged and the
reference marker is placed on the trace at the reference marker position.
•IfthemarkermodeisSpan Pair, the marker positions remain unchanged.
ThedifferencebetweenDelta Pair and Delta modesisthatinDelta Pair mode the reference
marker stays on the trace and you can adjust its trace point. The note (Tracking Ref)
appears on the Delta Pair key because, in effect, the reference marker “tracks” the trace. (By
comparison, in Delta mode the reference marker does not track changes in the trace results,
it remains anchored in amplitude and frequency.)
Once positioned, the markers stay on the trace points you have selected. Ref and Delta
markers maintain their displayed x-axis location, but not their frequency values when you
change a parameter that redefines the x-axis scale. Reset these markers when parameters
such as Span or Center Freq are changed. Adjusting the Span changes the difference
between the two markers. Changing the Center changes the center point of the two
markers. This function is useful in functions such as Band Power. Changing the frequency
or sweep time of the analyzer does not change the trace point of the markers. You cannot
move the markers off the screen.
Key Path: Marker
Factory Preset: Ref is the active parameter. Factory preset marker mode is Off.
Range: Refer to the [:SENSe]:SWEep:POINts command under “Points” on page
244.
Remote Command:
See “Marker” on page 177 for the command to select the control mode.
:CALCulate:MARKer[1]|2|3|4:X:POSition:STARt <param>
:CALCulate:MARKer[1]|2|3|4:X:POSition:STOP <param>
Sets the reference (Start), or delta (Stop) marker X position to a specified point on the X
axis in display points (values of 0 to 600, or the current number of points in the sweep).
The marker must already be on.
:CALCulate:MARKer[1]|2|3|4:X:POSition:STARt?
:CALCulate:MARKer[1]|2|3|4:X:POSition:STOP?
Returns the reference (Start), or delta (Stop) marker X position in display points.
Example: CALC:MARK3:MODE BAND activates or selects marker 3 and sets it to Delta
Pair. Refer to “Marker” on page 177.
CALC:MARK3:X:POS:STAR 0 moves the reference marker 3 to the left edge