Agilent Technologies E1441A Manuale Utente

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.