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User Manual
E727T0005, valid for E-727
BRO, 2019-06-28
Physik Instrumente (PI) GmbH & Co. KG, Auf der Roemerstrasse 1, 76228 Karlsruhe, Germany
Page 101 / 240
Phone +49 721 4846-0, Fax +49 721 4846-1019, Email
With WGR you can restart data recording while the wave generator is running. The recorded data
can be read with the DRR? command. See "Data Recording" (p. 65) for more information.
Figure 30: Block diagram of one wave generator
Application Notes
All wave generators can run simultaneously. All waveform output is synchronized because there is
a common pulse generator used by all wave generators. For that reasons, wave tables which are
supposed to run at the same time (each with one wave generator) should have the same length. If
the wave tables have different lengths, an output cycle will comprise only the number of points
given by the shortest table. This means that all waveform output is cut to the length of the
shortest waveform currently running.
Waveforms cannot be changed while they are being output by a wave generator. If you want to
modify a waveform with WAV, first stop any wave generator output from the associated wave
table.
The frequency of the wave generator output depends, among other factors, on the wave table
length. When you create waveforms, keep in mind that the usable frequency is limited by the
available amplifier power. If the frequency is too high, overheating of the amplifier(s) can occur,
and the piezo voltage output will be deactivated automatically.
When you use the wave generator to create white noise for a measurement (WAV command with
<WaveType> = "NOISE"), make sure that the wave table segment is at least as long as the duration
of the measurement. Otherwise, the noise sequence will be repeated during the measurement and
will no longer be white noise.
Wave generator output and analog control input:
It is possible to configure an axis for control by an analog input line while the wave generator
output is active for that axis. In that case, the wave generator will continue running, but its output
will no longer be used for control value generation. As long as the corresponding axis is set up to
be commanded by analog control input, you can stop the wave generator output, but not restart it.