California Instruments 2253i, Руководство пользователя

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User Manual 2253i / 2253iX
AMETEK California Instruments 81
4.4 Waveform Management
The iX Series employs independent arbitrary waveform generators for each phase. This allows the
user to create custom waveforms. In addition, three standard waveforms are always available. This
chapter covers issues that relate to defining, downloading and managing custom waveforms.
Note: i Series models do not support arbitrary waveform generation.
4.4.1 Standard Waveforms
For most AC applications, a sinusoidal wave shape is used. The sine wave is the standard waveform
provided on all i and iX Series models. This standard sine wave is always available and is the default
waveform at power-on unless overridden. On iX model power sources, two more standard waveforms
are available, square and clipped.
Figure 4-8: Selecting a Waveform
The square wave provides a high frequency content waveform with relative fast rise and fall times. Due
to AC amplifier bandwidth limitations, the frequency content of the standard square wave has been
kept within the amplifier’s capabilities. As the fundamental frequency is increased, the relative
contribution of higher harmonics is reduced.
The clipped sine wave may be used to simulate voltage distortion levels to the unit under test. The
total harmonic distortion level may be programmed in percent using the CLIP THD field directly below
the FUNC entry.
Note that changing the distortion level of the clipped waveform forces the AC source to regenerate the
clipped sine wave’s data points and reload the waveform register with the newly requested data. This
process requires the output to be dropped briefly. To avoid interrupting the voltage output to the unit
under test, set the clip level needed before closing the output relay and do not change it while the EUT
is under power. You can then toggle between the clipped sine wave and any other waveform in
memory without interrupting the output.
4.4.2 Creating Custom Waveforms
The iX controller supports up to 50 user defined waveforms in addition to the 3 standard waveforms.
Custom waveforms cannot be created from the front panel of the iX Series. Rather, they have to be
downloaded through the IEEE-488, LAN or USB interface.
Each waveform is defined by 1024 data points. Each data point can range between –1 and +1 (floating
point number). See the iX Compact Series programming Manual (P/N 6005-961) for details on
downloading waveforms.
Once downloaded, waveforms remain in non-volatile memory and will be visible in the WAVEFORMS
menu for selection. The user can assign a 12-character name to each custom waveform. Avoid using
any of the standard waveform names (SINUSOID, SQUARE or CLIPPED) as these names will not be
accepted.
Waveforms may be deleted using the IEEE-488, LAN or USB interface as well. Custom waveforms
cannot be deleted from the front panel however to avoid accidental erasure.