Vision™ MX280001A Spectrum Monitoring Application Programming Interface : Vision User Controls : Radio Monitor
 
Radio Monitor
The Radio Monitor user control combines several functions related to I/Q capture and AM/FM demodulation into a single interface.
The Radio monitor has four graph regions for displaying captured trace and I/Q data.
Lower-Left hand corner is the I/Q plot. There is a speaker icon on this plot that will attempt to demodulate and play a sound file from the captured I/Q data. This will just be noise if the capture is off-peak, or is too wide and contains a lot of noise or a mixture of other signals.
Top right is the RF sweep trace plot. This is a density plot, so traces are added to it as they are collected. The density plot is reset each time you press the RF Sweep button to begin a new acquisition.
Middle right is the Audio file plot. It displays the audio output from the demodulation. There is also a Speaker Icon on this window to replay what is shown in this window.
At the bottom right of the Remote Monitor window is the Spectrogram plot. This shows the same traces as the RF sweep graph, but in a spectrogram view. You can often tell that certain frequencies are FM modulated by the way the peak wiggles back and forth in the spectrogram.
 
Radio Monitor Example
Radio Monitor Icons
At the left of the Radio Monitor window are the main menu icons and program buttons that are defined below.
Radio Monitor Main Menu Icons
 
Radio Monitor Icon Definition
Save
Saves the current I/Q capture data to a disk file.
Open
Loads a saved I/Q Capture file into the Radio Monitor program.
A file may take a few seconds to several minutes to load. For wide bandwidth capture files, the file is split into time slices and FFT’s are used to get back the RF sweep for each time slice. Once the file is open, the trace data will be displayed and selecting a frequency in the trace graph will allow you to listen to an AM or FM signal at any frequency within the larger I/Q capture.
Refresh
Reloads the file header for the currently opened I/Q Capture file, if one exists. This button resets the parameter fields to match the loaded I/Q Capture file.
Volume Up
Increases the volume.
Volume Down
Decreases the volume.
Screenshot
Takes a picture of the Radio Monitor control and copies it to the Windows Clipboard.
Help
Opens online Help. Only visible if a file is assigned using the HelpFile property.
Radio Monitor Buttons
Button
Description
Remote Probe: The Remote Probe button captures basic system information for the designated probe.
RF Sweep: The RF Sweep button starts collecting traces from the target receiver and draws them in a density plot. The Sweep parameters specified in the section under this button are first sent to setup the sweep measurements.
I/Q Capture: The I/Q Capture button captures I/Q data from the target receiver. The bit resolution, capture length, bandwidth and center frequency are set according to the input fields below this button.
Frequency Marker: The Frequency Marker button does a peak search in the RF Sweep window and sets a marker at the peak power position. The Frequency is shown in the box below this button. The marker can also show a width that can be used to determine the appropriate I/Q capture bandwidth for a peak of interest.
Demodulation: The Save Demodulation button causes the most recently played AM/FM demodulation sound to be saved to a WAV file. Click the AM or FM radio buttons to select the demodulation mode.