Teledyne LeCroy PXA125 - Manual (Page 107)

User Manual PXA125
ArbConnection 3-93
Amplitude and Offset setting.
Equation You will be using the Equation field for writing your equations.
Equation syntax and conventions are discussed in the following.
Control Buttons There are five control buttons at the right corner of the dialog box.
Use the Preview button to preview an image of your equation, or use
the OK button to place your waveform on the waveform screen and to
leave the dialog box. The Browse button will open the waveform
browser so you can search for pre-stored waveforms to add to your
equation. The Operands button will expand the dialog box to show all
of the operands that are available for use in the Equation Editor and
the Cancel button will remove the dialog box from the screen and will
discard of any waveforms that you previewed with your Equation
Editor.
Writing Equations
The Equation Editor lets you process mathematical expressions and
convert them into waveform coordinates. As you probably already
know, waveforms are made of vertical samples. The number of
samples on your waveform is determined by the wavelength
parameter. For example, if you have 1024 horizontal points, your
equation will be computed along 1024 points as a function of the
vertical scale. Each vertical sample is computed separately and
placed along the horizontal axis. The points are graphically connected
to form a continuous waveform. However, if you zoom in on a
waveform line, you’ll see that the points are connected like a
staircase. In reality, the PXA125 generates its waveforms exactly as
shown on the screen however, if the waveform has many horizontal
points, the steps are hard to see.
Equations are always computed as a function of the vertical
(Amplitude) axis therefore the left side of your equation will always
look as Ampl(p)=, where “p” is the equation variables in units of
waveform points. You can write equations with up to 256 characters.
If the equation is too long to fit in the visible field, parts to the left or
right will scroll off the ends.
Equation
Conventions
The following paragraphs describe the conventions that are used for
writing an equation. To avoid errors, it is extremely important that you
make yourself familiar with these conventions before you plan your
waveforms.
Equations are written in conventional mathematical notation. You may
only enter the right part of the equation. The only limitation is that the
equation must be of a single variable that is directly related to the
current horizontal axis setting. Case is not important and spaces are
ignored. Numbers are entered in scientific notation. All calculations