Wavefrom Tab - Analog Devices EVAL-AD7124-4SDZ User Manual

UG-855

WAVEFROM TAB

The Waveform tab graphs the conversions and processes the
data, calculating the p-p noise, rms noise, and resolution (see
Figure 21).
Waveform Graph and Controls
The data waveform graph (Label 1) shows each successive
sample of the ADC output. Zoom in on the data using the
control toolbar (Label 2) in the graph. Change the scales on the
graph by typing values into the x-axis and y-axis.
Analysis Channel
The Noise Analysis section and histogram graph show the
analysis of the channel selected via the Analysis Channel
control (Label 3).
Samples
The Samples numeric control (Label 4) and batch control
(Label 5) set the number of samples gathered per batch and
whether a single batch or multiple batches of samples are
gathered. This control is unrelated to the ADC mode. The user
can capture a defined sample set or continuously gather batches
of samples. In both cases, the number of samples set in the
Samples numeric input dictates the number of samples.
Sample
Click SAMPLE (Label 6) to start gathering ADC results. Results
appear in the waveform graph (Label 1).
EVAL-AD7124-4SDZ User Guide
Channel Selection
The channel selection control (Label 7) chooses which channels
display on the data waveform, and also shows the analog inputs
for the channel labeled next to the on and off controls. These
controls only affect the display of the channels and have no
effect on the channel settings in the ADC register map.
Display Units and Axis Controls
Click the Display Units drop-down list (Label 8) to select whether
the data graph displays in units of voltages or codes. This control
affects both the waveform graph and the histogram graph. The
axis controls can be switched between dynamic and fixed. When
dynamic is selected, the axis automatically adjusts to show the
entire range of the ADC results after each batch of sample. When
fixed is selected, the user can program the axis ranges; the axis
ranges do not automatically adjust after each batch of sample.
CRC Error and Overall Error
The CRC Error LED indicator (Label 9) illuminates when
a cyclic redundancy check (CRC) error is detected in the
communications between the software and the AD7124-4. The
CRC functionality on the
must be enabled for this indicator to work. The Error Present
LED indicates if an overall error is present in the diagnostics
register. For this indicator to work, the check for the different
diagnostic errors must be enabled in the Error_EN register.
Noise Analysis
The Noise Analysis section (Label 10) displays the results of the
noise analysis for the selected analysis channel, which includes
both noise and resolution measurements.
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AD7124-4 is disabled by default and