WOLFRAM SYSTEM MODELER

AssignClockToTriggerHold

Generate a Boolean continuous-time trigger signal from a clocked Real input

Wolfram Language

In[1]:=
SystemModel["Modelica.Clocked.RealSignals.Sampler.Utilities.AssignClockToTriggerHold"]
Out[1]:=

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

This block creates a Boolean, continuous time, trigger signal whenever the clock of the input signal is active.

A particular use-case in which that block might be useful is the combination of "old-style" sampled blocks (i.e., "unclocked" discrete control functions implemented using equations between "when trigger then" clauses) with clocked blocks.

Example

The following example samples a sine signal with a periodic clock of 20 ms period. After that a continuous time Boolean trigger signal is generated at every clock tick of that sampled signal. The generated signal is used as trigger signal for an "old-style" TriggeredSampler block from the Modelica.Blocks.Discrete package:

AssignClockToTriggerHold_Model.png     AssignClockToTriggerHold_Result.png
model simulation result

Note, that it is clearly visible in the plot that the "old-style" discrete variables have an implicit zero-order hold semantics, while the new clocked variables are only active whenever their associated clock ticks. Just compare variable sample.y (clocked) with triggeredSampler.y (unclocked) to observe the difference.

Parameters (1)

y_start

Value: false

Type: Boolean

Description: Initial value of output signal

Connectors (2)

u

Type: RealInput

Description: 'input Real' as connector

y

Type: BooleanOutput

Description: Connector of Boolean output signal

Used in Examples (1)

AssignClockToTriggerHold

Modelica.Clocked.Examples.Elementary.RealSignals

Example of an AssignClockToTriggerHold block for Real signals