Agilent Technologies E4445A Saw User Manual


 
184 Chapter3
Instrument Functions: M - O
Marker
Instrument Functions: M - O
3.1.5 Span Pair
Sets the control mode for the selected marker to Span Pair (see “Marker” on page 177). In
Span Pair mode the display shows the difference between the delta marker and a reference
marker and enables you to adjust both the ref and delta markers. The start marker
number is indicated with a number and an R above the marker (for example, 1R)andthe
stop marker is indicated with a marker number. After you turn on the Span Pair function,
pressing the key again toggles between the two marker parameters you are controlling,
span and center.
Adjusting the Span (Span is underlined) changes the frequency difference between the two
markers. Adjusting Center (Center is underlined) maintains the marker spacing and
changes the frequency of the midpoint between the markers. Adjusting the span changes
the frequency difference between the two markers while maintaining the midpoint
between the two markers at a fixed frequency. Changing the center changes the center
point between the two markers while maintaining the frequency difference.
There are four conditions that can occur when
Span 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.
IfthemarkermodeisDelta Pair, the marker positions remain unchanged.
Thedifferencebetween
Span Pair and Delta modesisthatinSpan Pair mode the reference
marker stays on the trace and you can adjust its trace point.
Once positioned, the markers stay on the trace points on which they have been placed.
Changing the frequency or time of the analyzer does not change the trace point of the
markers, that is, they stay at the same horizontal position on the display.
You cannot move the markers off the screen. If you adjust either center or span to a value
that would cause one of the markers to move off screen, the marker will be placed at the
right or left side of the display, on the trace. Changing the Center marker changes the
center point of the two markers. This function is useful in functions such as Band Power.
Key Path:
Marker
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:CENTer <param>
Sets the mid point of the markers to a specific trace point.
:CALCulate:MARKer[1]|2|3|4:X:POSition:CENTer?