User Manual

:MEASure Commands 20
Keysight InfiniiVision 1000 X-Series Oscilloscopes Programmer's Guide 357
:MEASure:FALLtime
(see page 782)
Command Syntax
:MEASure:FALLtime [<source>]
<source> ::= {CHANnel<n> | FUNCtion | MATH | WMEMory<r>}
<n> ::= 1 to (# analog channels) in NR1 format
<r> ::= 1-2 in NR1 format
The :MEASure:FALLtime command installs a screen measurement and starts a
fall-time measurement. For highest measurement accuracy, set the sweep speed
as fast as possible, while leaving the falling edge of the waveform on the display. If
the optional source parameter is specified, the current source is modified.
Query Syntax
:MEASure:FALLtime? [<source>]
The :MEASure:FALLtime? query measures and outputs the fall time of the
displayed falling (negative-going) edge closest to the trigger reference. The fall
time is determined by measuring the time at the upper threshold of the falling
edge, then measuring the time at the lower threshold of the falling edge, and
calculating the fall time with the following formula:
fall time = time at lower threshold - time at upper threshold
Return Format
<value><NL>
<value> ::= time in seconds between the lower threshold and upper
threshold in NR3 format
See Also • "Introduction to :MEASure Commands" on page 345
• ":MEASure:RISetime" on page 368
• ":MEASure:SOURce" on page 371
NOTE
This command is not available if the source is FFT (Fast Fourier Transform).