Why is the timing in simulate signal not based on real time

[stefanusadrian]

on a simple program of reading the signal of simulate signal on a chart, why is the timing result is not based on real time

The simulate signal has 1 Hz frequency of square signal with 5 V amplitude, with sampling rate of 1kHz (default), and number of sample is 100 (default)

I set the chart to shows 5 second at a time, so there will be 5 pulse shown at a time. 

When I start the program, the pulse appear at really fast rate, clearly not 1 Hz, and when i use a stopwatch to compare the timing in labview and real time, when the stopwatch shows 10 s, the chart has already shown 15000, why is labview so much faster?

[JamesSouv]

Hello,

please try this out:

Right click on your simulated signal

select Properties

In the Timing section, please select:

Simulate acquisition timing.

Did it fix your problem?

Regards and Greetings,

James.

[stefanusadrian]

Thanks for the reply

It did, but the reading becomes slow, updated only once per second, when i decrease the number of samples into 1, it becomes faster

but i dont understand the magic behind it, i know about the sampling rate, but not the number of samples

Will you help me understand? thanks

[JamesSouv · Accepted solution]

Hello,

The Number of samples is the Number of samples that generates the signal.

If I may give you a general hint to understand what is done in a specific tool, VI… in LabVIEW, is the use of the Context Help (Ctrl + H).

Then you only have to point  your mouse (or click) in the desired field, and you will find a description.

If description is still not clear, you can click the Detailed help option.

(Please notice how I unchecked Automatic option in order to modify the Samples)

If you play around with this and will discover lot of useful stuffs.

After trying, if this solves your problem, please mark it as SOLVED, so that other users can find a solution quicker.

Good luck and have Fun programming in LabVIEW,

Regards and Thanks for the Kudo,

James.

PS: Here are some Links to understand the magic in LabVIEW

NI Learning Center

NI Getting Started

-Hardware Basics

-MyRIO Project Essentials Guide (lots of good simple circuits with links to youtube demonstrations)

-LabVEW Basics

-DAQ Application Tutorials

-cRIO Developer's Guide

Learn NI Training Resource Videos

3 Hour LabVIEW Introduction

6 Hour LabVIEW Introduction
Self Paced training for students
Self Paced training beginner to advanced, SSP Required
LabVIEW Wiki on Training