XBee Tech Tip: Using the XCTU Spectrum Analyzer Tool

Digi International
December 10, 2015

XCTU 6.3 features a brand new Spectrum Analyzer tool. This makes it possible to measure and test the spectrum using only an XBee radio. The tool generates a report of the noise level for each channel within the radio’s frequency band. With these data points, XBee users can select the optimal channel for their XBee network and troubleshoot network issues.

In this XBee Tech Tip, we’ll take a look at how to run the Spectrum Analyzer tool. Below is a quick screencast that takes you through adding the XBee device to XCTU to running a spectrum analysis and sorting through the data points collected. The video is followed with more information on the tool such as configuring the test and analyzing the network noise levels.

To get started, first access the tool by selecting it from the Tools drop down menu.

Device selection
The first section of the tool contains the device selection control populated with the devices that you have added to XCTU. Select the radio module you want to use to perform the analysis.

Analysis Configuration
The analysis configuration panel is located next to the device selection control. This section allows you to configure the spectrum analysis process:
This is the list of available settings:Screen Shot 2015-12-10 at 8.57.25 AM

  • Sampling interval (ms): Determines the time to wait in milliseconds before reading a new noise level sample of the RF channels.
  • Number of samples: Check this option to configure the number of samples to read in the spectrum analysis session.
  • Loop infinitely: Check this option to read samples infinitely until the spectrum analysis session is stopped manually.

When you have configured all the options, click Start Spectrum Analysis button to start reading samples and measure the noise level of each RF channel. You can manually stop the analysis at any time by pressing the same button, now displaying the text Stop Spectrum Analysis.

Data Presentation
When an analysis is started, the chart and channels list are filled with all the RF channels supported by the selected device. Note: the list of supported channels may vary depending on the device type and device region.

Channel Chart
This chart represents the noise level of all the RF channels. Each channel displays 1 bar with the current noise level and two tick marks representing the maximum noise level (green) and the minimum one (red).

Screen Shot 2015-12-09 at 4.20.16 PM

A blue line is also added to the chart indicating the average noise level of all channels. The spectrum analysis refreshes the noise levels of each channel continuously until the analysis ends or it is stopped.

Along the bottom of the chart, users can filter to hide or display the bars, the max and min noise values and the average noise level line.

Screen Shot 2015-12-09 at 4.20.32 PM

Once the spectrum analysis reaches the specified number of samples or is stopped, you can click on each channel to get specific values (seen above). This control displays the current noise level of a channel as well as its average, maximum and minimum noise level.

The Spectrum Analyzer feature supports Digi radios with the following protocols:

  • Zigbee (S2C Modules)
  • 802.15.4
  • DigiMesh
  • XTend Legacy
  • XTend DigiMesh
  • Digi Point

What do you want to learn next?
We hope you found this tutorial helpful! Let us know what you’d like to learn in the next XBee Tech Tip: http://bit.ly/xbeetechtip