Use the timing document to view, create, modify, save, and apply timing files (.digitiming). Timing files include period, edge multiplier (edge x), drive format, and edge information for pattern execution. Timing files currently can contain only one timing sheet, which is a collection of time sets. The Project Explorer window and document tab use an asterisk (*) to indicate unsaved changes.

Select File » New or select the Add Item button Add Item button (plus sign) on the toolbar on the Project Explorer window toolbar to create a new document. Double-click a .digitiming file in the Project Explorer window, or right-click the file and select Open from the context menu to launch the timing document.

The timing document displays time set configuration components, including format and edge placement. Together, these components define the digital waveform on a per-pin basis. You can define multiple time sets for different pattern vectors. Each time set can use a unique per-pin edge multiplier, format, and edge placement values. Each vector references only one time set. You can create as many time sets as required for the unique pin behavior combinations in a pattern burst. The digital pattern instrument limits the supported number of uniquely named time sets. For more information about the number of supported time sets, refer to the specifications document for the digital pattern instrument. You can create multiple timing files and apply those values to separate pattern bursts.

A time set can include timing definitions for multiple different pins or different pin groups. Each pin or pin group appears on a separate row in the timing document. You can define the same time set more than once for the same pin on different rows, if needed. When multiple definitions apply, pins or pin groups later in the list override components from earlier entries.

To adjust the order of the time set definitions, use the reorder arrows Up and down arrow buttons for reordering list items. to drag and drop rows.

Applying Time Sets

Select the Apply Time Sets button Apply Time Sets button icon or right-click the timing file (.digitiming) in the Project Explorer window and select Apply Time Sets from the context menu to delete any previously applied values and load all the time set values in the document on the instrument after you make changes. Applying time set values affects all sites, even disabled sites. The Digital Pattern Editor does not prompt you to reapply time set values when you enable a previously disabled site because the time set values have already been applied. The editor validates that all formulas resolve successfully, displays an error message, and highlights the related cell for formulas that include errors. The editor prompts you to apply the values in the active timing file when no timing values have previously been applied to the instrument or when previously applied timing values change directly in the timing document or indirectly through changes in the specifications document.

Configuring Time Sets

You can enter and edit numeric values or formulas for the time set components. Formulas can reference variables from specification files included in the project. By default, the timing document displays the formula definition. Click the Show Formulas/Show Computed Values button Show Formulas/Show Computed Values button icon. to toggle the formula or numeric value view. Hover over the cell to display a tooltip with the formula and resolved value. The document highlights unresolved values and related dependencies and displays a tooltip with error information. Timing files automatically update with the value changes you make in specifications files.

Double-click an empty row or start typing to create a time set and specify its values.

You can delete rows by selecting cells in the rows and selecting Delete Selected Row(s) from the context menu. Alternatively, select an entire row by clicking on the row header or select every cell in the row and use the <Delete> key.

You can set values for the following components for time sets. You must specify a value for each component. The timing document highlights unspecified components in orange.

  • Name — Specifies the name of the time set.
  • Period — Specifies the period of vectors that use the time set. A time set uses one period for all pins. Changing the period in one row updates all rows with that time set automatically.
    Note You can specify edges that exceed the period of the time set up to the limits the digital pattern instrument supports. However, all edges must still occur in order and must honor all minimum separation requirements. Do not schedule edges for future cycles before all edges of the current cycle are complete. Validation for these situations does not occur.
  • Pin Item — Specifies a pin or pin group defined in the pin and channel map.
    Note Currently, the Digital Pattern Editor does not support using system pins in patterns. Configure a shared pin connection in the Pin Map Editor to share a channel across multiple sites. Use that pin to burst across all sites.
  • Edge Multiplier — Specifies the edge multiplier for a time set. You can choose 1x or 2x multipliers. If you choose a 2x multiplier, you can specify values for the 2x edge components. Values include Drive Data2, Drive Return2, and Compare Strobe2. The document hides the 2x edge columns when it contains no 2x time sets. The document disables editing 2x edge cells for 1x time set rows.
  • Drive Format — Specifies one of the following drive formats, as illustrated in the following figures.
    Figure 1. Drive Formats, Including Surround by Complement

    Timing diagram comparing NR, RL, RH, and SBC drive formats across vector cycles and pin state transitions, showing signal behavior during drive, return, and off periods.

    Figure 2. Drive Formats, 2x Multiplier

    Timing diagram comparing NR, RL, and RH drive formats with a 2× multiplier across vector cycles, showing signal transitions, return states, and drive-off behavior.

    • NR — Non-return. Setting Drive Format to NR disables the Drive Return cell in that row and clears that cell if a value was present.
    • RL — Return to low.
    • RH — Return to high.
    • SBC — Surround by complement.
  • To configure edge components for each pin or each pin group per time set, use the following columns:
    • Drive On
    • Drive Data
    • Drive Return
    • Drive Data2
    • Drive Return2
    • Drive Off
    • Compare Strobe
    • Compare Strobe2
    Note On power-up, pins are in a high-impedance state. Some DUTs are sensitive to the initial state of a pattern burst. To avoid unexpected results, specify the initial pin state programmatically. Use the niDigital Write Static VI, the DigitalPinSet.WriteStatic .NET method, or the niDigital_WriteStatic C function. You can set the initial pin state interactively in the Digital Pattern Editor. Select the corresponding driver symbol in the Drive section of the Pin View pane. After each pattern burst, the last executed vector determines the ending pin state. The state persists until the next pattern burst starts or until you change the pin state or pin function.
    • Drive On — Specifies the delay from the beginning of the vector period for turning on the pin driver. This option applies only when the previous vector left the pin in a non-drive pin state (L, H, X, V, M, E).
    • Drive Data — Specifies the delay from the start of the vector period. The instrument drives the pattern value to the pin after the delay.
    • Drive Return — Specifies the delay from the start of the vector period. After that delay, the pin changes from pattern data to the return value specified by the format. Some drive formats do not support this field. The document disables editing when you select one of those formats.
    • Drive Data2 — Specifies a delay from the start of the vector period. After the delay, the 2x time set drives the second pattern value. The document disables editing this column for 1x time sets. The document hides this column if there are no 2x time sets.
    • Drive Return2 — Specifies a delay from the start of the vector period. After the delay, the pin switches from the second pattern value to the format-defined return value. Some drive formats do not support the Drive Return2 column. The document disables editing this field when the drive format does not support it. The document also disables editing this column for 1x time sets. The document hides this column if there are no 2x time sets.
    • Drive Off — Specifies the delay from the start of the vector period. After the delay the pin turns off the driver when the next vector period uses a non-drive symbol (L, H, X, V, M, E).
    • Compare Strobe — Specifies the time when the comparison happens within a vector period.
    • Compare Strobe2 — Specifies the time when a 2x time set's second comparison happens within a vector period. The document disables editing this column for 1x time sets. The document hides this column if there are no 2x time sets.
  • Comment — Specifies a text description for the time set row. This field does not accept the <Enter> or <Tab> keys.

Keyboard Shortcuts within the Timing Document

Action Shortcut
Apply time sets <Ctrl+L>