Measurement Computing DASYLab User Manual - Manual (Page 62)

DASYLab
© National Instruments Ireland Resources Limited | 7-3
Optimizing Processing Time
The overall operating performance of DASYLab depends on the hardware
resources of the computer, on the data acquisition device, and on the
complexity of the worksheet. The following section provides tips on how to
increase the DASYLab operating speed.
•
Increase the amount of memory (RAM) on your computer. If you often
write into the Windows swap file, your system slows down.
• The more powerful your computer is, the higher the sampling rates can
be.
• Disable unnecessary display functions, such as the grid display in the
display windows.
• Enable the fixed time base setting in the Axes menu.
• If you measure with a high sampling rate (for example, to process high
frequencies with an FFT), you preserve DASYLab resources if you use
the Separate module. To do so, insert the Separate module, which only
lets every hundredth data block pass between the modules Analog
Input and FFT. DASYLab calculates an FFT for every hundredth data
block, which includes high frequencies due to the high sampling rate.
If the measurement does not require an online display, you can first save the
data in a file and later read and evaluate the data off-line.
Significant Digits
The accuracy with which DASYLab process data depends on the transferred
data type. The modules usually work with the 8-byte double data type,
whereas the data is transferred in the worksheet over connecting cables with
just 4-byte float. The accuracy of the float data type is altogether 6 places.
This means that measurements with results in the value range of 0 to 4000
are only correct up to 2 decimal places. All subsequent decimal places are
only an approximation.