Audio Input Express VI
- Updated2023-02-21
- 2 minute(s) read
Owning Palette: High Throughput FPGA Personality VIs
Requires: myRIO Toolkit
Reads values from one or more audio input channels on the myRIO. Use this Express VI to read multiple samples for each channel at one time.
| Dialog Box Options |
| Block Diagram Inputs |
| Block Diagram Outputs |
Dialog Box Options
| Parameter | Description |
|---|---|
| Node name | Specifies the name of this Express VI. You can also double-click the name of this Express VI on the expandable node to edit the name. |
| Channel | Specifies the audio input channel from which to read the value. |
| Custom channel name | Specifies a custom name for the audio input channel that you select. |
| Delete Channel | Deletes the audio input channel that you select. |
| Add channel | Adds a new audio input channel to the channel list. You can add up to two audio input channels. |
| Sample rate | Specifies the sampling frequency of the input signal. Valid values are between 1 kHz and 44.1 kHz. If you specify a frequency that is invalid, this Express VI coerces the specified value to the nearest valid value when you click the OK button on the Express VI.
|
| Samples | Specifies the number of samples to read. The default is 1,000. Valid values must be greater than 0 and less than or equal to 10,000. |
| Latency | Displays the latency between two adjacent signal generation iterations. Refer to the Details section of this topic for more information about latency. |
| View Code | Displays the underlying code of this Express VI. |
| Connection Diagram | Shows the I/O connector pinouts on the myRIO or the roboRIO. The highlighted pinouts represent the channels that you configure. |
Block Diagram Inputs
| Parameter | Description |
|---|---|
| error in (no error) | Describes error conditions that occur before this node runs. |
Block Diagram Outputs
| Parameter | Description |
|---|---|
| channel name | Returns the value that this Express VI reads from the audio input channel that you select, where channel name is the name of the audio input channel. |
| error out | Contains error information. This output provides standard error out functionality. |
Audio Input Details
The following figure demonstrates the latency when you use the Audio Input Express VI to perform n samples read operations.
In the previous figure, the x-axis represents time and the y-axis represents amplitude. The waveform in blue represents the signal that the myRIO acquires. The red dotted line represents latency. When latency occurs, the myRIO does not acquire any signal. In other words, the time interval between two adjacent signal acquisition iterations is latency.
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