Tektronix TDS 500C User Manual

Using Features for Advanced Applications

TDS 500C, TDS 600B, & TDS 700C User Manual

The math waveform, derived from the sampled waveform, is computed based on
the following equation:

+ (X

)1)

* X

Where: 

X is the source waveform

Y is the derivative math waveform

T is the time between samples

Since the resultant math waveform is a derivative waveform, its vertical scale is
in volts/second (its horizontal scale is in seconds). The source signal is differen-
tiated over its entire record length; therefore, the math waveform record length
equals that of the source waveform.

To obtain a derivative math waveform:

1. Connect the waveform to the desired channel input and select that channel.

2. Adjust the vertical and horizontal scales and trigger the display (or press

AUTOSET).

3. Press MORE ➞ Math1, Math2, or Math3 (main) ➞ Change Math

Definition (side) ➞ Single Wfm Math (main). (See Figure 3–101).

4. Press Set Single Source to (side). Repeatedly press the same button (or use

the general purpose knob) until the channel source selected in step 1 appears
in the menu label. 

5. Press Set Function to (side). Repeatedly press the same button (or use the

general purpose knob) until diff appears in the menu label. 

6. Press OK Create Math Wfm (side) to display the derivative of the

waveform you input in step 1.

You should now have your derivative math waveform on screen. Use the
Vertical SCALE and POSITION knobs to size and position your waveform
as you require.