Manual

C HAPTER F OUR : 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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