DSP Blockset

Displaying Signals in the Time-Domain

The Vector Scope block can display both time-domain and frequency-domain data. It differs from the Spectrum Scope in that it does not compute the FFT of inputs.

Example: Displaying Time-Domain Data

In the model below, two frame-based signals are simultaneously displayed on the scope.

To create the model, first load the mtlb signal.

load mtlb            % Contains variables 'mtlb' and 'Fs'

Specify the following parameter values in the Signal From Workspace block:

• Signal = mtlb
• Sample time = 1
• Samples per frame = 16
• Form output after final data value = Cyclic Repetition

Specify the following parameter values in the Digital FIR Filter Design block:

• Filter type = Lowpass
• Filter order = 22
• Cutoff frequency = 0.25
• Window type = Hamming

Specify the following parameter values in the Scope properties pane of the Vector Scope block:

• Input domain = Time
• Time display span (number of frames) = 2

When you run the model, the Vector Scope block plots two consecutive frames of each channel at each update. You may want to set the Stop time in the Simulation Parameters dialog box to inf to allow the simulation to run longer. The following section provides a few tips for improving the display.

Viewing Signals

Improving the Appearance of the Display