This blocks defines the transfer function between the input u and the output y as approximative derivative (DT1):
k * s
y = ------------ * u
T * s + 1
The block can be continuous or discrete (with continuous parameterization).
If k=0, the state space realization of the block is specially constructed, in order that the D-part of PID controllers can be set to zero without introducing numerical problems.
If you would like to be able to change easily between different
transfer functions (FirstOrder, SecondOrder, ... ) by changing
parameters, use the general model class TransferFunction
instead and model a DT1 system with parameters
n = {k,0}, d = {T,1}.