blockHysteresisWithHold
Extends from Modelica.Icons.ObsoleteModel (Icon for classes that are obsolete and will be removed in later versions).
Information
Model for a hysteresis block that optionally allows to specify a hold time. During the hold time, the output is not allowed to switch.
When the input u becomes greater than uHigh, the
output y becomes true and remains true
for at least trueHoldDuration seconds, after which time it is allowed
to switch immediately.
When the input u becomes less than uLow, the output
y becomes false and remains false for
at least falseHoldDuration seconds, after which time it is allowed
to switch immediately.
This model for example could be used to disable an economizer, and not re-enable it for 10 minutes, and vice versa. Using hysteresis can avoid the distraction from the input noise.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | uLow | if y=true and u<uLow, switch to y=false | |
| Real | uHigh | if y=false and u>uHigh, switch to y=true | |
| Modelica.Units.SI.Time | trueHoldDuration | true hold duration | |
| Modelica.Units.SI.Time | falseHoldDuration | trueHoldDuration | false hold duration |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | u | Real input signal | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput | y | Boolean output signal |
Revisions
-
September 18, 2017, by Michael Wetter:
Refactored model to use Buildings.Controls.OBC.CDL.Logical.TrueFalseHold. -
June 26, 2017, by Jianjun Hu:
First implementation.