Agilent Technologies E8257D PSG User Manual page 112

Basic Digital Operation
Using Waveform Markers
Marker Point Edit Requirements
Before you can modify a waveform segment's marker points, the segment must reside in volatile
memory (see "Loading Waveform Segments from Non–volatile Memory" on page
In the dual ARB player, you can modify a waveform segment's marker points without playing the
waveform, or while playing the waveform in an ARB modulation format.
In an ARB modulation format, you must play the waveform before you can modify a segment's
marker points.
Saving Marker Polarity and Routing Settings
Marker polarity and routing settings remain until you reconfigure them, preset the signal generator,
or cycle the PSG power. To ensure that a waveform uses the correct settings when it is played, set
the marker polarities or routing (RF Blanking and ALC Hold), and save the information to the file
header (page 80). This is especially important when the segment plays as part of a sequence because
the previously played segment could have different marker and routing settings.
ALC Hold Marker Function (For Instruments with serial prefixes >=US4722/MY4722)
While you can set a marker function (described as
after you set marker points
cause power spikes or loss of power at the RF output.
Use the ALC hold function by itself when you have a waveform signal that incorporates idle periods,
or when the increased dynamic range encountered with RF blanking
The ALC hold marker function holds the ALC circuitry at the average (RMS) value of the sampled
points set by the marker(s). For both positive and negative marker polarity, the ALC samples the RF
output signal (the carrier plus any modulating signal) when the marker signal goes high:
Positive: The signal is sampled during the on marker points.
Negative The signal is sampled during the off marker points.
The marker signal has a minimum of a two sample point delay in its response relative to the
waveform signal response. To compensate for the marker signal delay, offset marker points from the
waveform sample at which you want the ALC sampling to begin.
NOTE
Because it can affect the waveform's output amplitude, do not use the ALC hold for longer
than 100 ms. For longer time intervals, refer to
98
(page 104), setting a marker function before setting marker points may
on the softkey label) either before or
Marker Routing
(page
"Setting Power Search Mode" on page
96).
109) is not desired.
283.
Chapter 3