Datasheet

Evaluation Board User Guide UG-280
Rev. 0 | Page 7 of 20
MAIN WINDOW
Menu Bar
File
This allows you to write the current set of data to a file for later
use, log data as it is gathered, and exit the program.
Board
This allows you to alter the contrast on the LCD display.
Buttons
Delete Data Clear Graphs
This allows you to delete the data displayed in the graph.
ADC Reset
This allows you to reset the AD7191 to its default (power-on)
settings.
ADC Setup
This opens the ADC Setup window, which reflects the current
status of Switch S6.
Low Noise Quick Test
This allows you to access the noise testing software.
Weigh Sc ale D emo
This allows you to access the weigh scale demonstration
software.
User Units Setup
This allows you to change the display units on the graph and
histogram.
Sampling
This allows you to sample continuously or to sample a specific
number of samples. When the Sampling: Capture Defined
Sample Set option is selected, the sample size is entered in the
Samples box.
Start Sampling
This allows you to read samples from the AD7191.
Data
Display Units
This allows you to display the conversions in hexadecimal,
decimal, volts, or user-specified units. If the conversions are
displayed in volts, the value of the reference voltage must be
entered in the Vref box.
Autoscale
This allows you to enable or disable the autoscale function on
the waveform plot.
X-scale
This allows you to have a fixed x-axis or a dynamic x-axis.
When the x-axis is fixed, the number of samples to display must
be entered in the X-scale Samples box.
Analysis
Channel
The data channel to be analyzed is selected using this button.
After Sampling
The software can process the conversions as they are being
gathered, or it can process the samples when the ADC has
completed the selected number of conversions.
Analyse All Samples
This allows you to process all samples gathered. Alternatively, you
can fix the sample size used for analyzing by selecting Analyse
Last # Samples. When Analyse Last # Samples is selected, the
sample size must be entered in the Last # Samples box.
The software captures all samples generated by the AD7191. If
the software fails to gather all samples, the message shown in
Figure 9 appears.
09880-009
Figure 9. Error Message When Samples Not Captured
The software may drop samples for the following reasons:
• The data is being analyzed in parallel with the gathering of
samples. You should delay the analysis until the samples
are gathered.
• Other programs are running on the PC.
• The PC is too slow.