


FOGPM Get FO process model specified by gain, delay,time constant,order.
Usage: FOGPM(K,L,T,type,alpha) Returns a plant model, specified by type:
'ffopdt' G = K / (1+T*s^alpha) * exp(-L)
'fipdt' G = K / s^alpha * exp(-L)
'ffoipdt' G = K / s^alpha * (1+T*s) * exp(-L)