YOKOGAWA DL6000 Series

App-4
IM DLM6054-01EN
Appendix 3 Integration and Differentiation of
Waveform Parameters
Differentiation and Integration
The computation of the derivative value uses the 5
th
order Lagrange interpolation formula to derive a
point of data from the five points of data before and after the target point.
The following equations use data f
0
to f
n
and I
0
to I
n
with respect to sampling time x
0
to x
n
. The
derivative and integrated values corresponding to these data points are computed as follows:
Differentiation (DIFF)
Point x
k fk’ = [fk-2–8fk-1 + 8fk+1–fk+2]
h = ∆x is the sampling interval (sec) (example h = 200 × 10
–6
at 5 kHz)
1
12h
Integration (INTEG)
Point x
0
I
0
= 0
Point x
1 I1 = (f0 + f1)h
Point x
2 I2 = (f0 + f1)h + (f1 + f2)h = I1 + (f1 + f2)h
Point x
n In = In-1 +
1
2
1
2
1
2
1
2
(f
n-1 + fn)h
1
2