FirstOrder

First order transfer function block (= 1 pole)

    FirstOrder

Library

Modelica/Blocks/Continuous

Description

This blocks defines the transfer function between the input uand the output y as first order system:

               k     y = ------------ * u            T * s + 1

If you would like to be able to change easily between differenttransfer functions (FirstOrder, SecondOrder, ... ) by changingparameters, use the general block TransferFunction insteadand model a first order SISO system with parameters
b = {k}, a = {T, 1}.

Example:   parameter: k = 0.3, T = 0.4   results in:             0.3      y = ----------- * u          0.4 s + 1.0

Parameters

FirstOrder_0

NameLabelDescriptionData TypeValid Values

mo_k

k

Gain

Scalar

mo_T

T

Time Constant

Scalar

mo_initType

initType

Type of initialization (1: no init, 2: steady state, 3/4: initial output)

Structure

mo_initType/choice1

No initialization (start values are used as guess values with fixed=false)

Number

0
1

mo_initType/choice2

Steady state initialization (derivatives of states are zero)

Number

0
1

mo_initType/choice3

Initialization with initial states

Number

0
1

mo_initType/choice4

Initialization with initial outputs (and steady state of the states if possible)

Number

0
1

mo_y_start

y_start

Initial or guess value of output (= state)

Scalar

FirstOrder_1

NameLabelDescriptionData TypeValid Values

mo__nmodifiers

Number of Modifiers

Specifies the number of modifiers

Number

mo__modifiers

Modifiers

Add new modifier

Structure

mo__modifiers/varname

Variable name

Cell of strings

mo__modifiers/attribute

Attribute

Cell of strings

'start'
'fixed'

mo__modifiers/value

Value

Ports

NameTypeDescriptionIO TypeNumber

u

implicit

Connector of Real input signal

input

1

y

implicit

Connector of Real output signal

output

1

See Also