This blocks defines the transfer function between the input u and the output y as approximated derivative:
k * s y = ------------ * u T * s + 1
If you would like to be able to change easily between different
transfer functions (FirstOrder, SecondOrder, ... ) by changing
parameters, use the general block TransferFunction
instead and model a derivative block with parameters
b = {k,0}, a = {T, 1}.
If k=0, the block reduces to y=0.