WOLFRAM SYSTEM MODELER
TransferFunctionDiscrete Transfer Function block |
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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 |
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.