National Instruments SCXI-1125 General Discussion of Typical Flowchart, Creating a Task Using DAQ Assistant or Programmatically, Adjusting Timing and Triggering

Chapter 5 Using the SCXI-1125

General Discussion of Typical Flowchart

The following sections discuss briefly considerations for a few of the steps

in Figure 5-1. These sections give an overview of some of the options and

features available when programming with NI-DAQmx.

Creating a Task Using DAQ Assistant or Programmatically

When creating an application, first you must decide whether to create the

appropriate task using the DAQ Assistant or programmatically in the ADE.

Developing your application using DAQ Assistant gives you the ability to

configure most settings such as measurement type, selection of channels,

excitation voltage, signal input limits, task timing, and task triggering. You

can access the DAQ Assistant through MAX or your NI ADE. Choosing to

use the DAQ Assistant can simplify the development of your application.

NI recommends creating tasks using the DAQ Assistant for ease of use,

when using a sensor that requires complex scaling, or when many

properties differ between channels in the same task.

If you are using an ADE other than an NI ADE, or if you want to explicitly

create and configure a task for a certain type of acquisition, you can

programmatically create the task from your ADE using functions or VIs.

If you create a task using the DAQ Assistant, you can still further configure

the individual properties of the task programmatically with functions

or property nodes in your ADE. NI recommends creating a task

programmatically if you need explicit control of programmatically

adjustable properties of the DAQ system.

Programmatically adjusting properties for a task created in the DAQ

Assistant overrides the original, or default, settings only for that session.

The changes are not saved to the task configuration. The next time you load

the task, the task uses the settings originally configured in the DAQ

Assistant.

Adjusting Timing and Triggering

There are several timing properties that you can configure through the

DAQ Assistant or programmatically using function calls or property nodes.

If you create a task in the DAQ Assistant, you can still modify the timing

properties of the task programmatically in your application.

When programmatically adjusting timing settings, you can set the task to

acquire continuously, acquire a buffer of samples, or acquire one point at a