Agilent Technologies X Series Manual page 463

Dependencies
Couplings
Readback Text
Initial S/W Revision
Backwards Compatibility:
The Screen Video function is intended to be very similar to the 8566 Video Output and the PSA Option
124. However, unlike the PSA, it is not always on; it must be switched on by the Screen Video key. Also,
unlike the PSA, there are certain dependencies (detailed above) – for example, the Quasi Peak Detector
is unavailable when Screen Video is on.
Futhermore, the PSA Option 124 hardware was unipolar and its large range was padded to be exactly
right for use as a Screen Video output. In the X-Series, the hardware is bipolar and has a wider range to
accommodate the other output choices. Therefore, the outputs won't match up exactly and users may
have to modify their setup when applying the X-Series in a PSA application.
Log Video (RF Envelope, Ref=Mixer Level)
Selects the analog output to be the log of the video signal. In this mode, the pre-detector data is output to
the Analog Out connector with a Log scaling. The output is referenced to the current level at the mixer,
does not depend on display settings like Reference Level or dB per division, and it is not influenced by
the selected detector or any digital flatness corrections or trace post-processing (like Trace Averaging),
but does change with input attenuation.
The output is designed so that full scale (1 V) corresponds to –10 dBm at the mixer. The full range (0–1
V) covers 192.66 dB; thus, 0 V corresponds to –202.66 dBm at the mixer.
Because the Screen Video output uses one of the two IF processing channels,
only one detector is available while Screen Video is selected. All active traces
will change to use the same detector as the selected trace when Screen Video
is activated.
Screen Video output is not available while any EMI Detector is selected
(Quasi Peak, RMS Average or EMI Average), because these detectors use
both IF processing channels. Consequently, if the user chooses an EMI
Detector, there will be no Screen Video output.
The output holds at its last value during an alignment and during a marker
count. After a sweep:
• If a new sweep is to follow (as in Continuous sweep mode), the output
holds at its last value during the retrace before the next sweep starts. If the
analyzer is in zero-span, there is no retrace, as the analyzer remains tuned
to the Center Frequency and does not sweep. Therefore, in zero-span, the
output simply remains live between display updates.
• If no new sweep is to follow (as in Single sweep mode), the output
remains live, and continues to show the pre-detector data
This function depends on optional capability; the key will be blanked and the
command will generate an "Option not available" error unless you have
Option YAV or YAS licensed in your instrument.
Screen Video output changes while in FFT Sweeps, so for measurements that
use exclusively FFT Sweeps, or if the user manually chooses FFT Sweeps, the
Screen Video output will look different than it does in swept mode.
Screen Video
A.04.00
Input/Output
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