Data Acquisition Toolbox

Trigger Types

For analog input objects, a trigger is defined as an event that initiates data logging to memory or to a disk file. Defining an analog input trigger involves specifying the trigger type with the TriggerType property. The TriggerType values that are supported for all hardware are given below.

Table 4-4: Analog Input TriggerType Property Values  

TriggerType Value	Description
{Immediate}	The trigger occurs just after the start function is issued.
Manual	The trigger occurs just after you manually issue the trigger function.
Software	The trigger occurs when the associated trigger condition is satisfied. Trigger conditions are given by the TriggerCondition property.

Many devices have additional hardware trigger types, which are available to you through the TriggerType property. For example, to return all the trigger types for the analog input object ai created in the preceding section:

• set(ai,'TriggerType')
  [ Manual | {Immediate} | Software | HwDigital ]
  

This information tells you that the National Instruments board also supports a hardware digital trigger. For a description of device-specific trigger types, refer to Device-Specific Hardware Triggers, or the TriggerType reference pages in Base Property Reference.

Note    Triggering can be a complicated issue and it has many associated properties. For detailed information about triggering, refer to Configuring Analog Input Triggers.

The Sampling Rate

The Samples to Acquire per Trigger