Can this be done in labView

[wondering]

I've been an electronic technician for the past 20 years and I'm interviewing with a company next week that wants someone with LabView experience. I just started reading "LabView for Everyone" by Jeffry Travis and Lim Kring, third edition with accompanied CD. I thought I could impress the prospective employer if I wrote a simple program to demonstrate during the interview but I might not have the time since I'm just getting started. Can anyone tell me if it's possible to model a low pass filter and change the component values and sine wave input and output a Bode plot? Are standard functions already available to do this so it could be done quickly? I'm just trying to figure out the scope of the task at this point and get some idea if it's a doable thing for a beginner. A response to my e-mail address would be greatly appreciated (michaelaz@cox.net), Thanks, Mike

[Ray.R]

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wondering wrote:

Can anyone tell me if it's possible to model a low pass filter and change the component values and sine wave input and output a Bode plot? Are standard functions already available to do this so it could be done quickly?

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Yes you can create models and the Bode plot is avaliable along with standard functions to implement such a solution.

Do you have LabVIEW or have access to it?  There is a 30 day fully functional (demo) that you can download.   Once you have LabVIEW installed, you can go under the Help menu and select Find Examples and do a search on the functions you need.  You should be able to find some examples.  You can also search this forum as well.

Please let your potential employer know that you are a novice programmer so that you do not set false expectations. 

R

[muks]

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Please let your potential employer know that you are a novice programmer so that you do not set false expectations.

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So true. Just imagine u get selected and you are immediately put in a indivijual project.That would be really  difficult.

[wondering]

Thanks for the rapid feedback guys,

Yes I do have the full version demo that came with the book and realize one can only scratch the surface of LabVIEW in the time I have before the interview. I'm not one to exaggerate skill levels because it would certainly come back to bite me as you alluded to. My impression is that the employer wants someone who can use LabView with programs that are already written for the purpose of data acquisition as opposed to an expectation the new hire (a technician not an engineer) will be proficient at creating new programs; I hope that’s the case anyway.  I’m familiar with PSpice and didn’t know if LabVIEW had the same capability of modeling and analyzing an electronic circuit but you’re saying that it does so I’ll start digging deeper into it. Thanks for the info, Mike

   

[TCPlomp]

Beware, LabVIEW doesn't have a clear PSpice like fuction.
There is the simulation toolkit, and based on normal mathematical routines one can build a simple circuit analyzer but my opinion is that the knowledge you gain is very little in respect to future LabVIEW use, it will only get you thinking, "gee, LabVIEW can't do anything Spice is much easier."

Ton

[LV_Pro]

LabVIEW is a pretty much full featured programming language. It has the capability to do complex mathematical computations, either with direct "LabVIEW" components, or executing equations in a couple of ways, but it isn't a direct analogy to PSpice, which is more an application than a language. As to there wanting someone with LabVIEW knowledge, "running" LabVIEW programs it pretty much falls into three broad categories; plain users, who have no knowledge of what is going on in the program, only have been given directions on how to run it, a "technician" who might be expected to open a given LabVIEW program and modify some constants or something of that nature to change its functionality, and a LabVIEW programmer, who should be able to write a LabVIEW program from start. Of course the later category has a whole spectrum of experience and knowledge. But don't make the mistake of thinking that doing the later task is easy because some of the initial examples are simple/easy.

Good Luck, hope you are joining the community of LabVIEWers

[wondering]

Hi,

 

I don't know your name?

I've been reading through the introduction manual that came with the evaluation CD and doing the examples all day. I'm still trying to figure out if it's possible to run a Bode plot of a filter design like you'd do in Spice and I'm thinking it's not possible because there aren't any filters you can put in the block diagram as a standalone function that I've been able to find. What I wanted to do is:

Wire a signal generator block capable of sweeping a selected frequency band to a standalone filter block which is configurable

Tape off the signal generator output as the reference input to the VI network analyzer

Take the output of the filter as the test input to the VI network analyzer 

Run the program and output a Bode plot of amplitude and phase over frequency

Reconfigure the filter and run another plot

Pretty much how you'd do it with real components and equipment or how you'd do a simulation of it in Spice. The one part that seems to be missing in LabVIEW is the filter block functions. Is this correct?

Thanks, Mike

[wondering]

Hi Mr. Monroe,

 

I've been reading through the introduction manual that came with the evaluation CD and doing the examples all day. I'm still trying to figure out if it's possible to run a Bode plot of a filter design like you'd do in Spice and I'm thinking it's not possible because there aren't any filters you can put in the block diagram as a standalone function that I've been able to find. What I wanted to do is:

Wire a signal generator block capable of sweeping a selected frequency band to a standalone filter block which is configurable

Tape off the signal generator output as the reference input to the VI network analyzer

Take the output of the filter as the test input to the VI network analyzer 

Run the program and output a Bode plot of amplitude and phase over frequency

Reconfigure the filter and run another plot

Pretty much how you'd do it with real components and equipment or how you'd do a simulation of it in Spice. The one part that seems to be missing in LabVIEW is the filter block functions. Is this correct?

Thanks, Mike

[Dennis_Knutson]

That's not true at all. Look at the Signal Processing>Filters palette. Or, on the Express>Signal Analysis palette, there is a Filter function. If you do not have these palettes, then you are using the base version of LabVIEW. I have no idea what is on this evaluation CD but a fully functional version of LabvIEW can be downloaded.

[wondering]

Thanks Dennis,

I do have a fully functional evaluation version and I'll look where you suggested. 

Thanks, Mike