Building a tone burst in Easywave

The SAG1021i arbitrary waveform generator and oscilloscopes with built-in function generators (series SDS2000X Plus, SDS2000X HD, SDS6000L, and SDS7000A/AP) do not have a Burst mode, which is a feature that is standard on Siglent’s SDG series of function generators.

However, with Easywave, a tone burst can be simply created as an arbitrary waveform and then played on the function generator.

Let’s use the example of a 3Vpp tone burst of 100 cycles at 1000Hz followed by an output 0V until the next burst occurs and this repeats at a rate of once per 500 msec.

This burst might be used to test and evaluate the frequency response, distortion, and transient behavior of audio systems or components, such as loudspeakers, microphones, or amplifiers.

A 100 cycle burst can simulate a musical note and may be used to when measuring linearity and distortion or testing loudspeakers and drivers.

Method for creating the wave form

Select the Equation Editor tool from the ribbon menu.

In the Settings frame, choose an Instrument Model that allows you to edit the number of samples.

Although there are 16384 maximum number of points, I find it useful to use a round number to simplify the math, so I set Samples, Sa(arb), to 16000.

The repeat rate of the tone burst is once per 500 msec. So the period of the waveform, T(arb), is 0.5 sec and the frequency is 1 / 0.5 sec = 2 Hz. So we set the frequency to 2 Hz.

I will use f(tone) to designate the frequency of the tone that we are generating for this example, 1kHz.

d(tone) will designate the time duration of f(tone). There are 100 cycles of f(tone) so:

D(tone) = 1 / 1kHz * 100 cycles = 0.1 sec

From this, we can calculate the number of samples, Sa(tone), that are needed for the tone:

Sa(tone) = Sa(arb) * D(tone) / T(arb) = 16000 * (0.1 / 0.5)= 3200

The tone waveform is described by:

Asin(2 * π * f(tone) * k * x)

              where,

                         A = 3

                         f(tone) = 1000 

                        k = (Sa(tone) / (Sa(arb)) * T(arb)

                            = (3200 / 16000) * 0.5 = 0.1

                         x is a variable used by range

Now we only need to write a few lines into the Equation editor to define the waveform:

     range(1,Sa(tone))

     A*sin(2*pi* f(tone)*k*x)

     range(Sa(tone)+1,Sa(arb))

     0

So, for our example, we enter:

    range(1,3200)

    3*sin(2*pi*1000*0.1*x)

    range(3201,16000)

    0

Then Compile the waveform.

Press OK.

Send the tone burst waveform to the waveform generator.

Verify the 500 ms interval.

Evaluate the resulting waveform and verify correct frequency.

 (1 kHz).