developing maths wave equation and make the equation variable.

[shidi5579]

Hi expert..

i am having difficulties to create  a program using mathematical wave equation and make the equation variable in 2 wave. e.g

square wave=2*a/pi*atan(tan(pi*t/period)) or sine wave= a*sin(2*f*t).i need to change the frequency and amplitude between 2 wave together separately.can anyone help me please..

[Tom.]

Hello,

The functions you are using to generate the Sine and Square waves will output that signal information in the form of a Waveform datatype. This datatype is a cluster of the raw data values, the start time (t0) and the time difference between each sample (dt). To use the raw data values in the formula node (they will be a 1D array of double values) you will need to use the Get Waveform Components VI that is located in Programming > Waveform on the functions palette.

The attached VI will illustrate what you need to do.

Hope this helps!

Tom
NIUK

[shidi5579]

Hello Tom,

Actually i am not very clear what are you try to  explain.I much appreciate  if you can give some pic.jpg to describe it.

Many thank,

[Tom.]

Sorry I didn't attach the VI. I have now attached the VI and a screenshot of the block diagram.

Good Luck!

Tom
NIUK

[shidi5579]

hello expert,

Thanks you advise previously.

i am having difficulties to write a program in Formula node with this equation. i just write in words format easy to understand.

can anyone help me please

[JonBowers]

Hi Shidi,

You can build the equation you attached from LabVIEW primitives. I have attatched a jpg of a vi does just that. The function you were probably having difficulty finding is the Yth root of X function located on the Exponential Functions palette under the Elementry and Special Functions under the Math Palette.

Regards

Jon B
Applications Engineer
NI UK & Ireland

[shidi5579]

Hi expert,

i am sorry i can't find the vi that you have told previous thread.

 i am using 7.1 version. can you tell me you are which version.

can you advise me other method

shidi

[Tom.]

Hello,

That function isnt availble in LabVIEW 7.1. You will have to use the Power of X function and pass 1/0.4 into the power terminal (Y) to achieve the 0.4 √ you wish.

Hope this helps.

Tom | NIUK