discretedifferential

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discretedifferential

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Library

Signal\Discrete

Use

Domains: Discrete. Size: 1-D. Kind: Block Diagrams.

Description

This model represents the discrete equivalent of the continuous differentiation:

 

output(0) = initial; (k = 0)

output(1) = (u(1) - initial)/sampletime; (k = 1)

output (k) = (u(k) - u(k-1))/sampletime; (k = n * T , n = 2,3,4,...

 

The sampletime T can be set in the Simulator (choose Properties, Simulation and Discrete System). The discrete transfer function of this model is:

 

H(z) = (z - 1) / ( z * sampletime)

 

which is the equivalent (using the backward difference transformation) of the continuous time transferential:

 

H(s) = s

 

Interface

Inputs

Description

input

 

Outputs

 

output

 

Parameters

 

initial

Initial value of the output.

Limitations

The input and output of this model are discrete signals. 20-sim will automatically detect the existence of discrete models. Each chain of discrete models will be assigned a specific sampletime. You can set this sample time to any desired value in the Simulator (choose Properties, Simulation and Discrete System).