Memory Function
Owning Palette: Utilities Functions
Installed With: Control Design and Simulation Module
Stores the value of the Input signal from the previous iteration of the simulation. Use this polymorphic function to transfer values from one iteration of the Simulation Loop to the next. The data type you wire to the Initial Value input determines the polymorphic instance to use.
| Dialog Box Options |
| Block Diagram Inputs |
| Block Diagram Outputs |
 Place on the block diagram |
Find on the Functions palette |
Dialog Box Options
| Parameter | Description |
|---|---|
| Parameters | Lists all the parameters associated with this function. Select a parameter from this list to configure the parameter. When you select a parameter, the parameter and its associated Parameter source control appear in the Parameter Information section of the configuration dialog box. |
| Preview | Displays a graphical preview, if available, of the function output or configuration. |
| Parameter Information | Contains the parameters you can configure for this function. You must select a parameter from the Parameters list to make that parameter and its associated Parameter source control visible in the Parameter Information section of the configuration dialog box. |
| Parameter source | Specifies whether you configure this parameter using the Configuration Dialog Box or a Terminal on the simulation diagram. The default value is Configuration Dialog Box. If you select Terminal, LabVIEW displays an input for that parameter on the simulation diagram, and you can wire values to that input to configure this function programmatically. If you select Configuration Dialog Box, LabVIEW removes that input from the simulation diagram. You then must set the value for this parameter inside the configuration dialog box. |
| execution type | Specifies when this function updates. You can choose from the following options:
|
| sample period (sec) | Specifies the length of the discrete time step, in seconds, of this function. If you enter a value of –1, this function inherits the discrete time step you specify for the simulation diagram. Otherwise, the value of sample period (sec) must be a multiple of the discrete time step you specify for the simulation diagram. The default value of sample period (sec) is 1. |
| sample skew (sec) | Specifies the length of time by which you want to delay the execution of this function. The default value is 0. The value of this parameter must satisfy the following relationship: 0 ≤ sample skew (sec) ≤ sample period (sec) |
Block Diagram Inputs
| Parameter | Description |
|---|---|
| execution type | Specifies when this function updates. You can choose from the following options:
|
| sample period (sec) | Specifies the length of the discrete time step, in seconds, of this function. If you enter a value of –1, this function inherits the discrete time step you specify for the simulation diagram. Otherwise, the value of sample period (sec) must be a multiple of the discrete time step you specify for the simulation diagram. The default value of sample period (sec) is 1. |
| sample skew (sec) | Specifies the length of time by which you want to delay the execution of this function. The default value is 0. The value of this parameter must satisfy the following relationship: 0 ≤ sample skew (sec) ≤ sample period (sec) |
| input | Specifies the signal to which you want to apply the function. |
| initial value | Specifies the value at the first iteration of the Simulation Loop. |
Block Diagram Outputs
| Parameter | Description |
|---|---|
| output | Returns the value of the input signal from the previous iteration of the Simulation Loop. On the first iteration of the Simulation Loop, output returns the value of the initial value parameter. |
Memory Details
Feedthrough Behavior
For this function, the input input has indirect feedthrough to the output output. All other input/output pairs have direct feedthrough behavior.
Example
Refer to the memory VI in the labview\examples\Control and Simulation\Simulation\Utilities directory for an example of using the Memory VI.
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