The Integral channel calculation provides a method of computing time-integrals with various reset methods. Integral works in real time during sampling and on pre-recorded data. The Integral dialog allows you to set up the Integral channel calculation.
1. Open the Integral dialog by selecting "Integral..." from any Channel Calculation pop-up menu.
- Standard Integral: use all data points.
- Absolute Value: integrate absolute values of data points.
- Positive Only: use only data points whose values are greater than 0.
- Negative Only: use only data points whose values are less than 0.
4. Set up the Reset type and any additional parameters this may require:
- No Reset: integral is not reset, and the integrated signal is summed indefinitely.
- Timed Reset: integral is reset periodically, at intervals specified in the text box to the right of the reset type menu.
- Reset Each Cycle: integral is reset each time the source signal passes through zero to a positive value.
- Time Constant Decay: In this mode, input samples are summed to generate the output, as for the standard integral mode. However, each time a new sample is added the sum is multiplied by a positive constant that is a little less than 1. For a constant input voltage Vmax, the resulting sum – namely, the integral output – approaches a maximum (Vmax.?) with the time constant (tau, ?) that is entered by the user. In electronic terms, this mode approximates the behavior of a 'leaky' analog integrator, or 'RC' low pass filter. Unlike a filter, the integral multiplies the output values by the sample period in seconds and correspondingly changes the units to V.s.
- Reset By Event: use a specific event to trigger the reset (this uses the options set in the Event Options Dialogue).
- Set Scale top and Scale bottom for the calculated data in terms of the source channel units or select Auto scale to automatically generate a suitable scale for the displayed data (Recommended if performing subsequent channel calculations, on the display channel.).Choose the number of Decimal places to show in the Range/Amplitude display.
7. Upon clicking "Okay", the continuous integral will appear in the channel you selected.