The NI-Digital Pattern Driver session operates in one of three programming states: Uncommitted, Committed, and Running.

Most digital pattern instrument settings don't take effect immediately when configured with the NI-Digital Pattern Driver. Rather, settings take effect when you commit the settings.

Note The PPMU has a simpler session state model than the pattern sequencer. Commit PPMU settings related to sourcing by calling PPMU Source. PPMU settings related to measuring take effect when you call PPMU Measure.
Figure 3. NI-Digital Pattern Driver Session State Diagram


Table 9. Session States
State Description
Uncommitted

A session enters this state after you initialize or reset.

In this state, the instrument remains configured as it was the last time you commit the session.

Settings you configure in this state aren't applied to the instrument until it enters the Committed or Running states.

Committed

A session enters this state after you explicitly commit the session or call an API that commits the session.

In this state, previously configured settings and certain automatically configured settings are applied to the instrument.

Note Bursting a pattern automatically commits the pattern sequencer settings.
Note Reading or writing static data automatically commits driver, comparator, and active load settings. This includes VIH, VIL, VOH, VOL, active load, and termination mode.
Running

The session enters this state after you burst a pattern or initiate.

In this state, you can dynamically reconfigure certain settings. For example, you can dynamically reconfigure all driver, comparator, and active load settings. This includes VIH, VIL, VOH, VOL, active load, and termination mode.

The session exits this state after you call the Abort or Abort Keep Alive.

Note Closing or resetting a session automatically aborts the session.