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Transfer waveforms at high speed, 61 transfer waveforms at high speed – Teledyne LeCroy X-STREAM OSCILLOSCOPES Remote Control User Manual

Page 67

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C

H A P T E R

F

O U R

:

Understanding and Managing Waveforms

WM-RCM-E Rev D

ISSUED: February 2005

61

Transfer Waveforms at High Speed

You must take several important factors into account if you wish to achieve maximum, continuous data

transfer rates from your instrument to the external controller. The single most important of these is to limit the
amount of work done in the computer. This means that you should avoid writing data to disk wherever

possible, minimize operations such as per-data-point computations, and reduce the number of calls to the I/O
system. To do this, you can try the following:

¾ Reduce the number of points to be transferred and the number of data bytes per point. The pulse

parameter capability and the processing functions can save a great deal of computing and a lot of data
transfer time if employed creatively.

¾ Attempt to overlap waveform acquisition with waveform transfer. The oscilloscope is capable of

transferring an already acquired or processed waveform after a new acquisition has been started. The total

time that the instrument takes to acquire events will be considerably increased if it is obliged to wait for
triggers (live time).

¾ Minimize the number of waveform transfers by using Sequence mode to accumulate many triggers

for each transfer. This is preferable to using WAVEFORM_SETUP to reduce the number of data points
for transfer. It also significantly reduces oscilloscope transfer overhead. For example, you could use

ARM; WAIT;C1:WF? (wait for the event, transfer the data, and then start a new acquisition). You could
also “loop” this line in the program as soon as it has finished reading the waveform.

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