Programming the Spectrum Monitor

Last updated: January 16, 2009

This section provides an example of how to use the Spectrum Monitor via the GPIB.

The following procedure assumes that the mobile station's antenna output is connected to the RF IN/OUT connector, and that the mobile station is transmitting a forward channel signal.

Configure the Spectrum Monitor parameters using the SETup subsystem.
Start the Spectrum Monitor using the INITiate subsystem.
Use the INITiate:DONE? command to determine if Spectrum Monitor results are available.
Use the FETCh? commands to obtain Spectrum Monitor results.
Use the CALCulate commands to set and query the Spectrum Monitor markers.

Programming Example

 
10       REAL Amplitudes(400)       ! Set up array to hold 401 amplitude results (trace data)
20       OUTPUT 714;"SETUP:SMONITOR:CONTINUOUS OFF"!Configures the Spectrum Monitor to
30                                                !single trigger mode.
40       OUTPUT 714;"SETUP:SMONITOR:COUNT:NUMBER 20"!Configures a multi-measurement
50                                                  !of 20.
60       OUTPUT 714;"SETUP:SMONITOR:TRIGGER:SOURCE IMMEDIATE"!Configure trigger source
70                                                     !to immediate.
80       OUTPUT 714;"SETUP:SMONITOR:FREQUENCY:SPAN 20 MHz"!Set frequency span
90       OUTPUT 714;"SETUP:SMONITOR:BWIDth:MANUAL 300 KHZ" !Decouples the frequency span
100                           ! and the resolution bandwidth, and sets the resolution bandwidth.
110       OUTPUT 714;"INITIATE:SMONITOR"!Start the Spectrum Monitor
120     !
130       OUTPUT 714;"FETCH:SMONITOR:INTEGRITY?"!Fetch SMON Integrity
140       ENTER 714;Integrity
150       PRINT "Spectrum Monitor Integrity: ";Integrity
160       IF Integrity=0 THEN                  !Fetch results if SMON
170           OUTPUT 714;"FETCH:SMONITOR:TRACE?"!has valid integrity.
180           ENTER 714;Integrity,Amplitudes(*)!Load valid results into array
190           PRINT "Trace Data Amplitude Results (dB):"
200           PRINT "--------------------------------------------------"
210           PRINT Amplitudes(*) !Prints the 401 stored data points.
220           PRINT "--------------------------------------------------"
230       ELSE
240           PRINT "Bad Integrity value =";Integrity
250           STOP
260       END IF
270     ! Move the marker to the signal peak and query the frequency and level
280       OUTPUT 714;"CALCULATE:SMONITOR:MARKER1:PEAK:MAXIMUM"
290       OUTPUT 714;"CALCULATE:SMONITOR:MARKER1:FREQUENCY?"
300       ENTER 714;Peak_frequency
310       PRINT "Maximum Peak Frequency (MHz): ";Peak_frequency
320       OUTPUT 714;"CALCULATE:SMONITOR:MARKER1:AMPLITUDE?"
330       ENTER 714;Peak_amplitude
340       PRINT "Maximum Peak Amplitude (dBm): ";Peak_amplitude
350       END

Returned Values

The results returned by this program are:

Integrity returns the Spectrum Monitor Integrity Indicator (0 means that the Spectrum Monitor completed with no errors).
Amplitudes() returns 401 points representing the amplitude results (in dBm) of the trace data.
Peak_frequency returns the frequency in MHz at marker 1. In this case, marker 1 is positioned at the highest peak value.
Peak_amplitude returns the amplitude in dBm at marker 1. In this case, marker 1 is positioned at the highest peak value.

Programming the Spectrum Monitor

Programming Example

Returned Values

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