Keysight Technologies X-Series, Руководство по программированию

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214 Keysight CXG, EXG, and MXG X-Series Signal Generators Programming Guide
Creating and Downloading Waveform Files
Waveform Structure
Waveform Structure
To play back waveforms, the signal generator uses data from the following
three files:
— File header
— Marker file
— I/Q file
All three files have the same name, the name of the I/Q data file, but the signal
generator stores each file in its respective directory (headers, markers, and
waveform). For information on file extractions, see “Commands for
Downloading and Extracting Waveform Data” on page 225 .
File Header
The file header contains settings for the ARB modulation format such as
sample rate, marker polarity, I/Q modulation attenuator setting and so forth.
When you create and download I/Q data, the signal generator automatically
creates a file header with all saved parameters set to unspecified. With
unspecified header settings, the waveform either uses the signal generator
default settings, or if a waveform was previously played, the settings from that
waveform. Ensure that you configure and save the file header settings for each
waveform.
Marker File
The marker file uses one byte per I/Q waveform point to set the state of the
four markers either on (1) or off (0) for each I/Q point. When a marker is active
(on), an output trigger signal is sent to a corresponding rear-panel BNC and/or
AUX IO connector pin. (For more information on active markers and their
output trigger signal location, refer to your signal generator’s User’s Guide.)
Because markers are set at each waveform point, the marker file contains the
same number of bytes as there are waveform points. For example, for 200
waveform points, the marker file contains 200 bytes.
Although a marker point is one byte, the signal generator uses only bits 0–3 to
configure the markers; bits 4–7 are reserved and set to zero. The following
example shows a marker byte.
If you have no RF output when you play back a waveform, ensure that the
marker RF blanking function has not been set for any of the markers. The
marker RF blanking function is a header parameter that can be
inadvertently set active for a marker by a previous waveform. To check for
and turn RF blanking off manually, refer to “Configuring the Pulse/RF
Blank” on page 318 .