Owning Palette: Signal Manipulation Express VIs
Requires: Base Development System
Accepts signals with any number of data points and produces packets of signals that use a packet size you specify.
| Dialog Box Options |
| Block Diagram Inputs |
| Block Diagram Outputs |
 Add to the block diagram |
 Find on the palette |
| Parameter | Description |
|---|---|
| Output segment size | Specifies the number of samples to include in each output segment. The default is 100. |
| Parameter | Description |
|---|---|
| Signals | Contains the input signal or signals. |
| Data Index | Contains the index of the repacked values. When the Express VI is in a While Loop, wire Data Index to the iteration terminal to take a larger array and iteratively generate packets of smaller size. If you do not wire Data Index to the iteration terminal, smaller data segments are collected into one larger packet. |
| error in | Describes error conditions that occur before this node runs. |
| Parameter | Description |
|---|---|
| Result | Returns the resulting data based on the configuration of the Express VI. |
| error out | Contains error information. This output provides standard error out functionality. |
| Data Available | Indicates if data is available to make a packet. |
To take a larger array and iteratively generate packets of smaller size, place the Repack Values Express VI in a While Loop and wire the Data Index input to the iteration terminal. Select the packet size for the Repack Values Express VI. The VI reads the Signals input once into a buffer during the first iteration of the While Loop. LabVIEW ignores this input for subsequent iterations. On each loop iteration, the Result output returns a segment of data starting from the first data point in the buffer. The Data Available output remains TRUE until there are not enough data points left to make a packet.
To collect smaller data segments into one larger packet, place the Repack Values Express VI in a While Loop and do not wire the Data Index input or wire a value of 0 to the Data Index input. The VI accepts new input on every loop iteration. The Data Available output remains FALSE until the VI has accepted enough data points to make a packet of the size you specified. When this Express VI returns the result packet, the Data Available output is TRUE. On the next iteration, it reverts back to FALSE.
This Express VI operates similarly to the following VIs and functions: