UNI-T UPO2000E Series, Руководство пользователя

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Press MATH type and select FFT to enter the FFT menu.
Source:
Press the source button to select any of CH1, CH2, CH3 or CH4 as the source of FFT operations.
Window:
Window function, press the window key to select Hamming, Blackman, Rectangle, or Hanning.
(1) Rectangle: It has the best frequency resolution and the worst amplitude resolution, which is similar to the one with
no window. It is suitable for measuring the following waveforms:
Transient or short pulse, the signal level is almost equal before and after this.
Equal amplitude sine wave with very similar frequency.
Wide-band random noise in a slowly changing spectrum.
(2) Hanning: Compared with the rectangle window, it has better frequency resolution, but poorer amplitude resolution.
It is suitable for measuring sine, periodic and narrow-band random noise waveforms.
(3) Hamming: The frequency resolution is slightly better than that of Hanning window, and it is suitable for measuring
transient or short pulse, and the waveform with great difference before and after the signal level.
(4) Blackman: It has the best amplitude resolution, and the worst frequency resolution. It is suitable for measuring the
single frequency signals or seeking higher harmonics.
Vertical Unit:
The unit of the FFT operation result. Press vertical unit to select Vrms or dBVrms. Vrms and dBVrms display the vertical
amplitude in a logarithmic way and a linear way. If you need to display the FFT spectrum in a large dynamic range,
dBVrms is recommended.
Screen Setting:
Press the screen setting key to set full screen or split screen.
(1) Split screen: Displays the source waveform and the waveform of FFT operation result separately.
(2) Full screen: Displays the source waveform and the FFT operation results on the same window that you can
observe the spectrum more clearly and make more accurate measurements.
FFT Operation Tips
Signals with DC components or deviations can cause errors or deviations in the FFT waveform components.
To reduce the DC component, the channel can be set to AC coupling.
To reduce the random noise and aliasing frequency components of the repetitive or single pulse, you can
set the oscilloscope acquisition mode to average acquisition.
7.3 Logic Operation
Press MATH type and select logic operation to enter its menu.
Expression:
Press the Expression key to select AND, OR, NOT, XOR.
(1) AND: Performs “AND” logic operation for every point of source 1 and source 2.
(2) OR: Performs “OR” logic operation for every point of source 1 and source 2.
(3) NOT: Performs “NOT” logic operation for every point of source 1, source 2 will not be displayed at this moment.
(4) XOR: Performs “XOR” logic operation for every point of source 1 and source 2.
Performs logic operations for all points of the source waveform voltage and displays the results. During operation, when
the source channel voltage value is greater than the threshold value, it is determined as logic “1”, otherwise it is logic “0”.
Converting waveforms to binary for logical operations is shown below:
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