.Modelica.Blocks.Discrete.TransferFunction

Information

The discrete transfer function block defines the transfer function between the input signal u and the output signal y. The numerator has the order nb-1, the denominator has the order na-1.

          b(1)*z^(nb-1) + b(2)*z^(nb-2) + ... + b(nb)
   y(z) = -------------------------------------------- * u(z)
          a(1)*z^(na-1) + a(2)*z^(na-2) + ... + a(na)

State variables x are defined according to controller canonical form. Initial values of the states can be set as start values of x.

Example:

     Blocks.Discrete.TransferFunction g(b = {2,4}, a = {1,3});

results in the following transfer function:

        2*z + 4
   y = --------- * u
         z + 3

Revisions

Release Notes:

• November 15, 2000 by Hans Olsson:
  Converted to when-semantics of Modelica 1.4 with special care to avoid unnecessary algebraic loops.
• June 18, 2000 by Martin Otter:
  Realized based on a corresponding model of Dieter Moormann and Hilding Elmqvist.