Keysight E6680A - Page 413

3 IQ Analyzer (Basic) Mode
3.3 Streaming Measurement
described in the section SCPI Operation and Results Query in the topic
Programming the Instrument.
For details of how to start/stop streaming, see "How To Start and Stop Streaming"
on page 415 below.
Remote Command Results for Streaming
The following table shows the returned results of the : FETCh|:MEASure|:READ
queries, depending on the specified value of n. Note that the marker values are x, y
pairs.
n Return Value
0 Returns unprocessed I/Q trace data, as a series of trace point values, in volts. The I values are listed first in
each pair, using the 0 through even-indexed values. The Q values are the odd-indexed values
Not specified
or 1
Returns the following comma-separated scalar results:
1.
FFT peak is the FFT peak amplitude
2.
FFT frequency is the FFT frequency of the peak amplitude
3.
FFT points is the Number of points in the FFT spectrum
4.
First FFT frequency is the frequency of the first FFT point of the spectrum
5.
FFT spacing is the frequency spacing between the FFT points of the spectrum
6.
Time domain points is the number of points in the time domain trace used for the FFT. The number of
points doubles if the data is complex instead of real. See the time domain scalar description below
7.
First time point is the time of the first time domain point, where time zero is the trigger event
8.
Time spacing is the time spacing between the time domain points. The time spacing value doubles if
the data is complex instead of real. See the time domain scaler description below
9.
Time domain returns a 1 if time domain is complex (I/Q) and complex data will be returned. It returns a
0 if the data is real. (raw ADC samples) When this value is 1 rather than 0 (complex vs. real data), the
time domain points and the time spacing scalers both increase by a factor of two
10.
Scan time is the total scan time of the time domain trace used for the FFT. The total scan time = (time
spacing) x (time domain points − 1)
11.
Current average count is the current number of data measurements that have already been combined,
in the averaging calculation
2 Returns the trace data of the log-magnitude versus time (that is, the RF envelope)
3 Returns the I and Q trace data. It is represented by I and Q pairs (in volts) versus time
4 Returns spectrum trace data. That is, the trace of log-magnitude versus frequency (the trace is computed
using a FFT)
5 Returns the averaged trace data of log-magnitude versus time (that is, the RF envelope)
6 Not used
7 Returns the averaged spectrum trace data (that is, the trace of the averaged log-magnitude versus
413 IQ Analyzer Mode User's &Programmer's Reference