STEP_FUNCTION

Block Screenshot

Contents

• Step Function

• • Palette

  • Description

  • Data types

  • Dialog box

  • Default properties

  • Example 1

  • Example 2

  • Interfacing function

  • See also

  • Authors

Palette

• Sources palette

Description

In its simpler use this block output a step signal between two definable levels Initial Value and Final Value starting at a specified time Step Time.

The step function is defined by the following equation:

where t0 is the Start Time, s0 the Initial Value and sf the Final Value.

You can also specify vector or matrice values, for the parameters Initial Value and Final Value. The parameters are expanded to column vectors. and in this case, you obtain multiples output that start at the same Step Time.

The table below shows different combinations

Initial value size	Final value size	Output size	Condition

Data types

• Output: scalar or column vector of double data type. The size is determined by the parameters Initial Value and Final Value

Dialog box

• Step Time

  The time, in seconds, when the output jumps from the Initial Value parameter to the Final value parameter.

  Properties : Type 'vec' of size 1.

• Initial Value

  The block output i is equal to the ith Initial Value until the simulation time reaches the Step Time parameter.

  Properties : Type 'vec' of size -1.

• Final Value

  The block output i jump to ith Final Value when the simulation time reaches the Step Time parameter.

  Properties : Type 'vec' of size -1.

Default properties

• always active: no

• direct-feedthrough: no

• zero-crossing: no

• mode: no

• regular outputs:

  - port 1 : size [-1,1] / type 1

• number/sizes of activation inputs: 0

• number/sizes of activation outputs: 0

• continuous-time state: no

• discrete-time state: no

• object discrete-time state: no

• name of computational function: csuper

Example 1

This diagram shows the use of the STEP_FUNCTION block to obtain the response to a step signal of a first order's system defined by a transfer function. Open this example in Xcos.

Example 2

This diagram shows the use of STEP_FUNCTION to obtain four step signals Open this example in Xcos.

Interfacing function

• SCI/modules/scicos_blocks/macros/Sources/STEP.sci

See also

• RAMP — Ramp
• CURV_f — Curve
• Sigbuilder — Signal creator/generator

Authors

Ramine Nikoukhah - INRIA