Cirrus Logic CDB5461AU - Manual (Page 21)

CDB5461AU
DS661DB1 21
2.8.7.6 Cycle Count
The value in Cycle Count field will be written to the CS5461A’s Cycle Count register. Cycle Count determines the
length of one computation cycle. Cycle Count should be selected appropriately according to the Data to Collect se-
lection. For example, if the Data to Collect is instantaneous Current, Voltage, or Power, it is better to set Cycle Count
to 1. If the data to collect is RMS Current, RMS Voltage, or Average Power, Cycle Count should be set to a value
that makes one computation cycle to be a even multiple of the line frequency.
2.8.7.7 Accept Button
When this button is pressed, the current settings will be saved, and the user will return to the Data Collection window.
2.8.8 Collecting Data Sets
To collect a sample data set:
1. In the Data Collection Window, press the Config button to bring up the Configuration Window and
view the current settings.
2. Select the appropriate settings from the available options (see the section on the Configuration Win-
dow) and press the Accept button.
3. The Data Collection Window should still be visible. Press the Collect button to begin collecting data.
4. Once the data has been collected, it can be analyzed, printed, or saved to disk.
2.8.9 Retrieving Saved Data from a File
The CDB5461AU software allows the user to save data to a file, and retrieve it later when needed. To load a previ-
ously saved file:
1. Pull down the Setup option and select Disk. A file menu will appear.
2. Find the data file in the list and select it. Press the select button to return.
3. Go to the Data Collection Window, and press the Collect button.
4. The data from the file should appear on the screen. To select a different file, repeat the procedure.
2.8.10 Analyzing Data
The evaluation software provides three types of analysis tests: Time Domain, Frequency Domain, and Histogram.
The Time Domain analysis process acquires conversions to produce a plot of magnitude versus conversion sample
number. The Frequency Domain analysis process acquires conversions to produce a plot of magnitude versus fre-
quency using the Fast-Fourier Transform (results up to Fs/2 are calculated and plotted). Also statistical noise calcu-
lations are calculated and displayed. The Histogram analysis test process acquires conversions to produce a
histogram plot. Statistical noise calculations are also calculated and displayed.