Pre

Breaks algebraic loops by an infinitesimal small time delay (y = pre(u): event iteration continues until u = pre(u))

    Pre

Library

Blocks/Logical

Description

This block delays the Boolean input by an infinitesimal small time delay and therefore breaks algebraic loops. In a network of logical blocks, in every "closed connection loop" at least one logical block must have a delay, since algebraic systems of Boolean equations are not solvable.

The "Pre" block returns the value of the "input" signal from the last "event iteration". The "event iteration" stops, once both values are identical (u = pre(u)).

Parameters

Pre_0

NameLabelDescriptionData TypeValid Values

mo_pre_u_start

pre_u_start

Start value of pre(u) at initial time

Scalar

true
false

Pre_1

NameLabelDescriptionData TypeValid Values

mo_u

u

u

Structure

mo_u/fixed

fixed

Cell of scalars

true
false

mo_u/start

start

Cell of scalars

mo_y

y

y

Structure

mo_y/fixed

fixed

Cell of scalars

true
false

mo_y/start

start

Cell of scalars

Ports

NameTypeDescriptionIO TypeNumber

u

implicit

Connector of Boolean input signal

input

1

y

implicit

Connector of Boolean output signal

output

1