CLAD Data Acquisition & Instrument Control 4

Question 1

What is the purpose of the NI-DAQmx DAQmx Control Task VI set to 'Commit' state?

Accepted Answer

It programs the hardware and reserves resources before calling Start, reducing start latency

Answer

The Commit state programs hardware registers and allocates resources so the transition to Running (Start) is faster, useful for time-critical applications.

Question 2

In SCPI (Standard Commands for Programmable Instruments), what does the '*RST' command do?

Accepted Answer

Resets the instrument to its factory default state

Answer

*RST is an IEEE 488.2 common command that resets an instrument to its defined factory default settings without affecting communication parameters.

Question 3

Which NI-DAQmx property allows you to apply a custom linear scaling (slope and offset) to convert raw DAQ voltages into engineering units?

Accepted Answer

DAQmx Channel Property (Custom Scale)

Answer

A custom scale created in MAX or via DAQmx Scale VIs and applied through the channel's Custom Scale Name property converts raw voltage to physical units (e.g., °C, PSI).

Question 4

What is the effect of selecting 'RSE' (Referenced Single-Ended) mode when measuring a grounded signal source?

Accepted Answer

It works correctly because both signal and device share the same reference ground

Answer

RSE is appropriate for grounded signal sources because the signal already has a ground reference that matches the DAQ device's AIGND, avoiding ground loops.

Question 5

A user calls DAQmx Read inside a While Loop for continuous acquisition. What is the correct placement of DAQmx Start Task and DAQmx Stop Task?

Accepted Answer

Start Task before the loop; Stop Task after the loop exits

Answer

Start Task should be called once before the loop to arm the hardware, and Stop Task should be called once after the loop to cleanly terminate acquisition.

CLAD Practice Test

CLAD Practice Test

CLAD Data Acquisition & Instrument Control 4