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Initial Value

Output specified value until first sample time hit

Library

Signal Management

Description

This block establishes an initial value for an event-based signal. Before the first sample time hit at the input port, the value of the output signal is the Value until first sample time hit parameter value. Starting from the first sample time hit, the output signal is identical to the input signal.

The following model fragment illustrates block usage in a feedback loop. When the simulation starts, the Initial Value block provides an initial value of 1 that opens the gate to permit the first entity to advance into the feedback loop. Without a nonzero initial value, no entity would arrive at the servers and the Signal Latch block would never experience any events.

    Note:   The IC block in the Simulink® library set operates in a time-based manner and is not suitable for event-based signals.

Ports

Signal Input Ports

LabelDescription
NoneThe first sample time hit in this signal causes the block to stop using the initial value from the block dialog box. From then on, the output signal is identical to the input signal. This signal must be an event-based signal.

Signal Output Ports

LabelDescription
NoneThe value is either the initial value in the block dialog box or the input signal value, depending on whether the input signal has had a sample time hit yet during the simulation.

The initial output value is the value of the Value until first sample time hit parameter. This value is in effect strictly before the first sample time hit of the input signal.

Dialog Box

Value until first sample time hit

The value to output before the first sample time hit of the input signal. The value of this parameter must have the same dimensions, data type, and complexity as the input signal.

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