WOLFRAM SYSTEMMODELER

TransferFunction

Discrete Transfer Function block

Wolfram Language

In[1]:=
SystemModel["Modelica.Blocks.Discrete.TransferFunction"]
Out[1]:=

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

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

Parameters (4)

samplePeriod

Value:

Type: Time (s)

Description: Sample period of component

startTime

Value: 0

Type: Time (s)

Description: First sample time instant

b

Value: {1}

Type: Real[:]

Description: Numerator coefficients of transfer function.

a

Value: {1}

Type: Real[:]

Description: Denominator coefficients of transfer function.

Outputs (3)

sampleTrigger

Type: Boolean

Description: True, if sample time instant

firstTrigger

Type: Boolean

Description: Rising edge signals first sample instant

x

Type: Real[size(a, 1) - 1]

Description: State of transfer function from controller canonical form

Connectors (2)

u

Type: RealInput

Description: Connector of Real input signal

y

Type: RealOutput

Description: Connector of Real output signal