:WAVeform Commands
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Keysight InfiniiVision M9241/42/43A PXIe Oscilloscopes SCPI Programmer's Guide
1171
The number of points transferred to the computer is controlled using the
:WAVeform:POINts command (see
). If :WAVeform:POINts MAXimum is
specified and the instrument is not running (stopped), all of the points that are
displayed are transferred. This can be as many as 4,000,000 in some operating
modes. Fewer points may be specified to speed data transfers and minimize
controller analysis time. The :WAVeform:POINts may be varied even after data on a
channel is acquired. However, this decimation may result in lost pulses and
transitions. The number of points selected for transfer using :WAVeform:POINts
must be an even divisor of 1,000 or be set to MAXimum. :WAVeform:POINts
determines the increment between time buckets that will be transferred. If POINts
= MAXimum, the data cannot be decimated. For example:
•
:WAVeform:POINts 1000
— returns time buckets 0, 1, 2, 3, 4 ,.., 999.
•
:WAVeform:POINts 500
— returns time buckets 0, 2, 4, 6, 8 ,.., 998.
•
:WAVeform:POINts 250
— returns time buckets 0, 4, 8, 12, 16 ,.., 996.
•
:WAVeform:POINts 100
— returns time buckets 0, 10, 20, 30, 40 ,.., 990.
Analog Channel Data
NORMal Data
Normal data consists of the last data point (hit) in each time bucket. This data is
transmitted over the programming interface in a linear fashion starting with time
bucket 0 and going through time bucket n - 1, where n is the number returned by
the :WAVeform:POINts? query (see
). Only the magnitude values of
each data point are transmitted. The first voltage value corresponds to the first
time bucket on the left side of the screen and the last value corresponds to the
next-to-last time bucket on the right side of the screen. Time buckets without data
return 0. The time values for each data point correspond to the position of the data
point in the data array. These time values are not transmitted.
AVERage Data
AVERage data consists of the average of the first n hits in a time bucket, where n is
the value returned by the :ACQuire:COUNt query (see
). Time buckets
that have fewer than n hits return the average of the data they do have. If a time
bucket does not have any data in it, it returns 0.
This data is transmitted over the interface linearly, starting with time bucket 0 and
proceeding through time bucket n-1, where n is the number returned by the
:WAVeform:POINts? query (see
). The first value corresponds to a point
at the left side of the screen and the last value corresponds to one point away from
the right side of the screen. The maximum number of points that can be returned
in average mode is 1000 unless ACQuire:COUNt has been set to 1.
PEAK Data
