Agilent Technologies E1441A user service Creating and Storing an Arbitrary Waveform

Creating and Storing an Arbitrary Waveform

frequencies. Since these signals are non-repetitive, all frequency components cannot be harmonically related to the window length. You should be careful in these situations to minimize end-point discontinuities and spectral leakage.

The following is an overview of the steps required to download and output an arbitrary waveform. The commands used for arbitrary waveforms are listed on page

Chapter 2, “Application Programs”, contains an example program which shows the use of arbitrary waveforms. You may find it useful to refer to the program after reading the following section in this chapter.

1. Select the waveform frequency, amplitude, and offset.

Use the APPLy command or the equivalent FREQ, VOLT, and VOLT:OFFS commands to select the frequency, amplitude, and offset of the arbitrary waveform. Because the APPLy command also changes duty cycle, modulation type, trigger source, and trigger slope, you must place the APPLy command first in any sequence of configuration commands.

2. Download the data points into volatile memory.

You can download between 8 and 16,000 points per waveform.

The waveform can be downloaded as floating-point values or binary integer values. Use the DATA VOLATILE command to download floating-point values between -1 and +1. Use the DATA:DAC VOLATILE command to download binary integer values between -2047 and +2047.

To ensure that binary data is downloaded properly, you must select the order in which the bytes are downloaded using the FORM:BORD command.

3. Copy the arbitrary waveform to non-volatile memory.

You can output the arbitrary waveform directly from volatile memory (as described in step 2) or you can copy the waveform to non-volatile memory. Use the DATA:COPY command to copy the waveform to non-volatile memory.

4. Select the arbitrary waveform to output.

You can select one of the five built-in arbitrary waveforms, one of four user-defined waveforms, or the waveform currently downloaded to volatile memory. Use the FUNC:USER command to select the waveform.

5. Output the currently selected arbitrary waveform.

Use the FUNC:SHAP USER command to output the waveform previously selected with the FUNC:USER command.

Chapter 2 Agilent E1441A Application Information 47