The Differentiator object calculates the time derivative of the input value:
y = (x – X)/(t – T), for t > T
= Y , for t = T
where:
y = present output value for the differentiator
x = present input to the differentiator
t = present simulation time
Y = output value for the differentiator at the last update time
X = input to the differentiator at the last update time
T = simulation time at the last update
The value returned by the Differentiator is calculated on demand. The update signal received from the Controller is used only to record the values Y, X, and T used in the calculation.