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Bandung
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how to make bode plots in Labview 7.1 without using Control Toolbox

I'm trying to make a bode plots from transfer function using Labview 7.1. My installed labview not contains any toolbox, so I have to create the block diagram of bode plots my self. I have a problem when creating the phase bode plots for polinomial with conjugate roots pairs. Suppose the polinomial is ax^2+bx+c, with a,b,c is the polinomial coefficients. If b coefficients is negatif, i  have no problem, because the phase is start at 0, and the final value is 180. But if the b coefficient is positive, the phase plots starts at -180 and it's final value is 0. So, if there is any one who can helps me to give any solution, i'll really appreciate that. Or if there is any of you who had made the program to create the bode plots from a transfer function, i hope you can share the code with me. Thank you.
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Kalin T
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Re: how to make bode plots in Labview 7.1 without using Control Toolbox

Hi Bandung,

I would encourage you to purchase the Control Design Toolkit. It features many different graphical tools to design and analyze control systems. There are multiple examples on our website as well. Just search for Bode plots. Otherwise feel free to consult Chapter 7 of the CD Toolkit manual which talks about Bode plots. 
http://www.ni.com/pdf/manuals/371057d.pdf

Kalin T
Applications Engineer
National Instruments

Kalin T.
National Instruments
Member
Bandung
Posts: 2
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Re: how to make bode plots in Labview 7.1 without using Control Toolbox

Thank you for your reply. I've trying to download some of the example, but still, I can't open it in my labview, since my installed labview is not supported for tyhat program (there is no control tool box in my labview) If I have to installed the control toolbox for my labview, is there any free software? Because honestly, I have no available money to buy that. Thank you... :smileyhappy:
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CMal
Posts: 415
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Re: how to make bode plots in Labview 7.1 without using Control Toolbox

Bandung,

Without the Control Design Toolkit, you would need to create your own Bode plot algorithms in LabVIEW.  The document that Kalin linked should be helpful for that.  I don't know of any free software that replaces the Control Design Toolkit.  You mentioned that you had already started programming, but you didn't say which VIs you are using.  Let me know what you have done so far, and I may be able to help.

 

Chris

Applications Engineer

National Instruments

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fr@nk
Posts: 21
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Re: how to make bode plots in Labview 7.1 without using Control Toolbox

Do these toolkits, Control Design orSound & Vibration Analysis, provide for hardware in the loop (control DAQmx hardware to generate stimulus waveforms and collect response waveforms) ? I don't see anything in chapter 7 that mentions hardware.

 

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JanGvK
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Re: how to make bode plots in Labview 7.1 without using Control Toolbox

Where can i find the CD Bode VI to create a Bode plot talked about in chapter 7?

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Greg_S-Video
Posts: 224
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Re: how to make bode plots in Labview 7.1 without using Control Toolbox

Hello JanGvK

 

The CD Bode VI is part of the NI LabVIEW Control Design and Simulation Module.  Here is the link for this product should you wish more information.  

http://sine.ni.com/nips/cds/view/p/lang/en/nid/203826

 

Thank you very much for your interest in LabVIEW!

Sincerely,

Greg S.
Applications Engineering Specialist | Automated Test
Multimedia Test, Vision, Control Design, Motion
National Instruments
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charlieangel
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Re: how to make bode plots in Labview 7.1 without using Control Toolbox

Thanks. Was looking for this product information for some time. :smileyhappy:

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pflo
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Re: how to make bode plots in Labview 7.1 without using Control Toolbox

[ Edited ]

 

I am trying to make a Bode plot without entering the transfer function. I have used a signal from a generator and a RC filter.

I have already downloaded the Control Toolbox but I don t know how to use it in my problem.

 

Thank you

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Kira_T
Posts: 186
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Re: how to make bode plots in Labview 7.1 without using Control Toolbox

Hey pflo,

Are you using LabVIEW 7.1?  Can you explain the problem that you are having with the using the Bode Plot VI?  Below please find links to some documentation on the Control Design Toolkit.  With further information on your problem I will be able to better assist you with the toolkit.  
Regards,
Kira T