Teledyne LeCroy PXA125 - Manual (Page 21)

User Manual PXA125
Portrayal 1-7
smaller segments and different waveforms can be loaded into
individual segment. The various segments may then be loaded into a
sequence table to generate long and complex waveforms. The
sequence table can link up to 4096 segments, while each segment
can loop up to 128 K times.
Remote Control The instrument must be used in conjunction with a host computer. All
of its functions, modes and parameters are fully programmable using
SCPI commands and syntax. There are three ways to program the
Model PXA125, the first being low-level programming of each
individual parameter, using SCPI commands. The second alternative
is to use ArbConnection for high-level programming. ArbConnection
is a software package supplied with the PXA125 that simulates a
mechanical front panel. It has all the necessary push buttons,
displays and dials to operate the instrument as if you were using it on
the bench. The third alternative is using application specific drivers,
such LabVIEW.
The PXA125 must be programmed to generate waveforms.
Therefore, it is recommended that the user becomes familiar with its
basic features, functions and programming concepts as described in
this and subsequent chapters.
Frequency Agility The instrument generates its sample clock from a DDS circuit (direct
digital synthesis). The DDS circuit enables frequency agility through
the complete frequency range of the PXA125. Having such an
enormous range opens the door for a wide range of applications such
as wide band sweep, FSK and frequency modulation. The PXA125
can generate FSK, Ramped FSK and Linear or Logarithmic sweep.
The instrument can also frequency modulate its carrier using one of
its built-in waveforms, or with can also generate any user-defined
modulating signal, which can be downloaded using the FM wave
composer.
Multi-Instrument
Synchronization
There are applications requiring 2 or more synchronized channels.
Synchronization between completely independent, free-running
instruments is not an easy task. Besides distribution of the sample
clock to all instruments, each instrument has to be told when to start
generating waveforms so that all waveforms start from the same point
and with the same phase. Also, triggering multiple instruments to
achieve synchronization is not enough because it will generate a jitter
of
± 1 count.
The PXA125 is using Backplane, daisy-chained connections to
synchronize between modules and the only limitation of the number
of synchronized instruments is determined by the size of the cage.
Supplied
The instrument is supplied with a CD that includes an Instruction