LeCroy PXA125, Руководство пользователя

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User Manual PXA125
Programming Reference 4-71
TRACe
Subsystem
The TRACe subsystem contains commands, which allow definition of
segments and their corresponding length, addition and deletion of
segments, and the loading of waveform data. Sequence commands
control segments links and loops. Description of the SendBlock()
command is also given. This command places PXA125 in a special
data transfer mode where the generator’s message-based interface is
bypassed and data is loaded directly from the data bus. Optional
nodes were omitted from these commands. Defaults are shown in
bold. General description of arbitrary waveforms is also included in
this section.
Keyword Parameter Form Default, Low Limit,High
Limit
:TRACe
:DEFine <segment_number>,<length>
:DELete <segment_number>
:DELete:ALL
:SELect (?)
<segment_number>
:SEQuence #<header><binary_block>
:ADVance (?) {AUTOmatic|STEP|SINGle|MIXed} AUTOmatic
:SOURce (?) {EXTernal|INTernal|TTLTrig0-7|STAR} EXTernal
:DEFine <link>,<seg_#>,<loop>,<mode>
:DELete:ALL
Arbitrary
Waveforms
Arbitrary waveforms are generated from digital data points, which are
stored in memory. Each data point has a vertical resolution of 14 bits
(16384 points), i.e., each sample is placed on the vertical axis with a
precision of 1/16384. The Model PXA125 has the following waveform
memory capacity:
2 Meg – standard memory configuration
Each horizontal point has a unique address - the first being 00000
and the last depends on the memory option. In cases where smaller
waveform lengths are required, the waveform memory can be divided
into smaller segments.
When the instrument is programmed to output arbitrary waveforms,
the clock samples the data points (one at a time) from address 0 to
the last address. The rate at which each sample is replayed is defined
by the sample clock rate parameter. The PXA125 provides
programmable sample clock rates from 100 mS/s to 100 MS/s.
Unlike the built-in standard waveforms, arbitrary waveforms must first
be loaded into the instrument's memory. Correct memory
management is required for best utilization of the arbitrary memory.
An explanation of how to manage the arbitrary waveform memory is