Agilent Technologies E4406A VSA manual 276

Language Reference

MEASure Group of Commands

n	Results Returned
not specified or	Returns the following comma-separated scalar results:
n=1	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 scaler 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) Χ (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, Service mode	Returns the trace data of the log-magnitude versus time. (That is, the RF
only	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, Service mode	Returns the averaged trace data of log-magnitude versus time. (That is, the
only	RF envelope.)
6	Not used.
7	Returns the averaged spectrum trace data. That is, the trace of the
	averaged log-magnitude versus frequency.
8	Not used.
9, Service mode	Returns a trace containing the shape of the FFT window.
only

276 Chapter 5