Keysight M8121A, User Manual

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Keysight M8121A Arbitrary Waveform Generator User Guide 117
Remote Programming 6
:TRACe Commands
:TRACe
commands should be used when working with the M8121A
internal memory. With the exception of the
:TRACe[1|2]:DWIDth[?]
command, they do not apply when streaming data over the ODI port.
Use the
:TRACe
subsystem to control the arbitrary waveforms and their
respective parameters:
• Select the DAC width in direct mode and the interpolation factor in
interpolated mode.
• Create waveform segments of arbitrary size with optional initialization.
• Download waveform data into memory.
• Delete data from the waveform memory.
Direct and Interpolated Mode
In direct mode, arbitrary waveforms are generated directly from the DAC
values in the waveform data. Each DAC value has a resolution of 12 bits or
14 bits.
In interpolated mode the waveform data consists of I/Q sample pairs. They
are first interpolated and then sent to the internal IQ modulator. The result
is sent to the DAC. I and Q values have a size of 15 bits each.
Waveform Memory Capacity
DAC values and I/Q samples are stored in a dedicated waveform memory.
The capacity of this memory in samples depends on the waveform output
mode and the installed memory option. The waveform memory size is
1,048,576 bytes, but the maximum number of samples is dictated not only
by the memory size but also the waveform granularity discussed in the
next section.
NOTE
:TRACe commands must follow the waveform length rules as outlined in
the Data Source Tab section.