Creating a User Defined Function-It’s

easy and simple. User-defined

function = XML + MATLAB script

The Keysight Infiniium user-defined function consists

of two components: an XML file and a MATLAB script

file.

The XML file defines the components of the graphical

user interface that appears on the “Math” dialog box

shown in the right side in Figure 3. An example XML

file used to create a user interface for a Butterworth

low-pass filter is shown in Figure-1. You will define the

name of the function, abbreviation, source types, and

controls in the XML file. The Infiniium user-defined

function can support up to two sources (one source,

two sources, or clock/data combination) and two

controls. It also comes with a standard XML schema

if you wish to validate your XML file. (Look on public

Web sites for a free XML syntax checker that you can

use in conjunction with the XML schema.)

The MATLAB script (the .m script file) will be the

main program of the function, which is developed in

the MATLAB environment using MATLAB’s software

tools and programming language. Figure 2 shows

an example of a Butterworth low-pass filter shown

in the MATLAB editor. The functions “butter” and

“filter” available in MATLAB and its Signal Processing

Toolbox are the essential components for making

this user-definable filter (Signal processing toolbox is

standard for N8806A.

Multiple custom user defined functions are already

provided with the Infiniium oscilloscope when you

purchase the N8806A UDF option. Provided functions

include Butterworth filtering, FIR, LFE, and RTEye.

Use MATLAB to create your own new functions or

modify and execute existing functions to meet your

own unique testing challenges.

Figure 2. MATLAB script example (shown in the MATLAB editor)

Figure 1. XML file example

User Defined Function with

MATLAB software

03 | Keysight | N8806A User Defined Function for Editing and Execution for Infiniium Oscilloscopes - Data Sheet