Table Of Contents

Capture Waveform Configurations

Last Modified: November 23, 2020

Use the capture waveform configuration document to view, modify, save, and load capture waveform files (.digicapture). Use the capture functionality when the data you need to acquire is site-specific or only determined at run time, such as when you need to read registers or test converters. You can receive multiple capture waveforms with the same configuration in a single pattern burst. Use the capture_start, capture, and capture_stop opcodes to store values when you burst a pattern. An asterisk (*) next to a filename in the Project Explorer window and in the document tab indicates that the file has been modified but not saved.

Select File»New or click the Add Item button Add Item on the Project Explorer window toolbar to create a new document. Create a single .digicapture file for each individual capture waveform you require. Double-click a .digicapture file in the Project Explorer window or right-click the file and select Open from the context menu to launch the capture waveform configuration document. You can also use the NI-Digital LabVIEW, .NET, or C API to load capture waveform configurations you create with the capture waveform configuration document. Refer to the Related information section at the end of this topic for a link to more information about source and capture functionality.

Configuring Waveforms

You must specify values for the following components of the waveform. Options that do not apply dim based on the values you specify.

  • Waveform Name — Specifies the name of the waveform.
  • Status — Indicates one of the following states of the waveform:
    • Not Loaded — The waveform has not been loaded on the digital pattern instrument.
    • Loaded — The waveform has been loaded on the digital pattern instrument.
    • Out of Sync — The waveform has been loaded on the digital pattern instrument but has been modified since it was loaded.
  • Waveform Type — Specifies one of the following types of waveforms:
    • Serial — Specifies that the waveform uses the serial configuration. When you configure the capture functionality for serial use, each vector that contains a capture opcode serially shifts 1 bit on pins using the pin state V.
    • Parallel — Specifies that the waveform uses the parallel configuration. When you configure the capture functionality for parallel use, the entire waveform sample is captured on all specified pins in parallel for each vector that contains a capture opcode. Use the pin state V for each pin on each such vector that corresponds to the pins for which you want to capture waveform samples.
  • Sample Format — Specifies one of the following options to display data in decimal (no prefix), hexadecimal (0x prefix), or binary (0b prefix) format. Saving capture data uses the format you specify for the waveform file.
  • Sample Width — Specifies the width in bits of each serial sample when you select Serial for the Waveform Type. Valid values are 1-32.
  • Bit Order — Specifies whether to evaluate the most significant bit (MSB) or the least significant bit (LSB) first when capturing a sample of a serial waveform.
  • Pins/Pin Groups — Specifies the pins or pin groups configured for the waveform. Use the type-ahead drop-down menu to select valid pins and pin groups.

Loading Waveforms

The Digital Pattern Editor prompts you to load waveforms on the instrument before bursting a pattern if the pattern directly uses a waveform, including waveforms used in patterns that the pattern jumps to. You can also click the Load Waveform button Load or Apply on the toolbar or right-click the waveform file in the Project Explorer window and use the context menu to manually load the current waveform on the instrument. You must specify a name and at least one pin for the waveform. You cannot load a waveform with the same name as another already loaded waveform. Click the Unload All Patterns and Waveform Configurations button Unload to remove all source and capture waveforms and patterns from the instrument. If you modify and save the waveform, you must unload and reload the waveform for the changes to take effect on the instrument. The Digital Pattern Editor prompts you to reload modified files before bursting a pattern.

When you load a parallel source or capture waveform through the Digital Pattern Editor, the order of pins you specify in the Pins/Pin Groups configuration determines the mapping for the bits in each sample. For example, the left-most bit maps to the left-most pin you specify, and each subsequent bit maps to each subsequent specified pin. For pin groups, the left-most bit maps to the top pin of the pin group, and each subsequent bit maps to the subsequent pin in the pin group.

Capture Results

Select View»Capture Results or click the Show Capture Results View button Show Capture Results View on the capture waveform configuration document toolbar or on the pattern document toolbar to view the capture waveform data from the instrument for the last pattern burst. The capture waveform data updates with each burst.


Recently Viewed Topics