Tektronix, Inc. P6240, User Manual

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Appendix B: Algorithms
B–4
TLS 216 User Manual
(Hysteresis
×
Amplitude)
MidRef – (Hysteresis
×
Amplitude)
MidRef
MCross1
(StartCycle)
MCross2
MCross3
(EndCycle)
Figure B–1: MCross Calculations
Waveform[<0.0 ... RecordLength–1.0>]
holds the acquired data.
TPOS is the location of the sample just before the trigger point (the time
reference zero sample). In other terms, it contains the domain reference location.
This location is where time = 0.
TSOFF
is the offset between
TPOS
and the actual trigger point. In other words, it
is the trigger sample offset. Values range between 0.0 and 1.0 samples. This
value is determined by the instrument when it receives a trigger. The actual zero
reference (trigger) location in the measurement record is at (
TPOS
+
TSOFF
).
The automated measurements are defined and calculated as follows.
The difference between the high level and low level of a waveform. The logic
scope determines the high and low levels using the method set in the Measure
menu: Min-Max or Histogram.
Amplitude
=
High
–
Low
The arithmetic area for one waveform. Remember that one waveform is not
necessarily equal to one cycle. For cyclical data you may prefer to use the cycle
area rather than the arithmetic area.
if
Start
=
End
then return the (interpolated) value at
Start
.
Otherwise,
Measurement
Algorithms
Amplitude
Area