User Manual

622 Keysight InfiniiVision 1000 X-Series Oscilloscopes Programmer's Guide
28 :WAVeform Commands
There are four types of waveform acquisitions that can be selected for analog
channels with the :ACQuire:TYPE command (see page 187): NORMal, AVERage,
PEAK, and HRESolution. When the data is acquired using the :DIGitize command
(see page 143) or :RUN command (see page 158), the data is placed in the
channel buffer of the specified source.
Once you have acquired data with the :DIGitize command, the instrument is
stopped. If the instrument is restarted (via the programming interface or the front
panel), or if any instrument setting is changed, the data acquired with the :DIGitize
command may be overwritten.You should first acquire the data with the :DIGitize
command, then immediately read the data with the :WAVeform:DATA? query (see
page 628) before changing any instrument setup.
A waveform record consists of either all of the acquired points or a subset of the
acquired points. The number of points acquired may be queried using
:ACQuire:POINts? (see page 180).
Helpful Hints:
The number of points transferred to the computer is controlled using the
:WAVeform:POINts command (see page 631). If :WAVeform:POINts MAXimum is
specified and the instrument is not running (stopped, in other words), all of the
points that are displayed are transferred. This can be the full oscilloscope
acquisition memory in some operating modes. You can ask for fewer points 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 page 631). 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