.IDEAS.Controls.OBC.CDL.Logical.TrueFalseHold

Information

Block that holds a true or false signal for at least a defined time period.

Whenever the input u switches to true (resp. false), the output y switches and remains true for at least the duration specified by the parameter trueHoldDuration (resp. falseHoldDuration). After this duration has elapsed, the output will be y = u.

This block could for example be used to disable an economizer, and not re-enable it for 10 min, and vice versa.

Simulation results of a typical example with trueHoldDuration = falseHoldDuration = 1000 s.

Revisions

• January 13, 2025, by Antoine Gautier:
  Merge elsewhen clauses.
  This is for Buildings, issue 4082.
• August 26, 2024, by Antoine Gautier:
  Resolved an issue with unit impulse signals.
  This is for Buildings, issue 3966.
• June 13, 2024, by Antoine Gautier:
  Refactored with synchronous language elements.
  This is for Buildings, issue 3787.
• November 12, 2020, by Michael Wetter:
  Reformulated to remove dependency to Modelica.Units.SI.
  This is for Buildings, issue 2243.
• September 18, 2017, by Michael Wetter:
  Improved event handling.
• July 14, 2017, by Michael Wetter:
  Corrected model to set output equal to input during initialization.
• June 13, 2017, by Michael Wetter:
  Reimplemented model using a state graph to avoid having to test for equality within tolerance, and to correct a bug. This implementation is also easier to understand.
  This is for Buildings, issue 789.
• May 24, 2017, by Milica Grahovac:
  First implementation.