Data Acquisition Toolbox

Evaluating the Analog Input Object Status

You can evaluate the status of an analog input (AI) object by

• Returning the values of certain properties
• Invoking the display summary

Status Properties

The properties associated with the status of your AI object allow you to evaluate

• If the device object is running
• If data is being logged to the engine or to a disk file
• How much data has been acquired
• How much data is available to be extracted from the engine

The analog input status properties are given below.

Table 4-5: Analog Input Status Properties

Property Name	Description
Logging	Indicate if data is being logged to memory or to a disk file.
Running	Indicate if the device object is running.
SamplesAcquired	Indicate the number of samples acquired per channel.
SamplesAvailable	Indicate the number of samples available per channel in the data acquisition engine.

When you issue the start function, Running is automatically set to On. When the trigger executes, Logging is automatically set to On and SamplesAcquired keeps a running count of the total number of samples per channel that have been logged to the engine or a disk file. SamplesAvailable tells you how many samples per channel are available to be extracted from the engine with the getdata function.

When the requested number of samples are acquired, SamplesAcquired reflects this number, and both Running and Logging are automatically set to Off. When you extract all the samples from the engine, SamplesAvailable is 0.

Acquiring Data with a National Instruments Board

The Display Summary