01-04-2012 11:46 AM
I am going to achieve impedance in labview. For development work, I will work with a 6220 DAQ and a small RC circuit, generating the voltage from the DAQ, and recording the output voltage in the inputs of the DAQ.
Therefore, I am looking for a network analyser vi.
Does anyone have something I could start with?
01-05-2012 08:37 AM
Thanks for your post. I have a few questions to help you get started with your application.
- What sort of RC network filter are you working with?
- What have you got working so far in LabVIEW?
- What specific hardware are you using to input AC to your circuit?
I believe that you would not be able to output an AC voltage to your circuit from an NI-6220 card, as it does not have an analog output channels. A good place to start reading voltages from your DAQ card would be in the LabVIEW example finder. This can be found by opening LabVIEW, and on the labVIEW getting started page » click on Find Examples. Alternatively within a LabVIEW VI click on Help » Find Examples. This will open up the LabVIEW example finder. Under Hardware Input and Output » DAQmx » Analog Measurements » Voltage. In here there are a large amount of examples of reading in analog voltages using DAQ vi's.
01-05-2012 09:17 AM
This part of the project is just development, the main part is impedance on fuel cells with Labview (electrochemical devices generating voltage and current).
1) RC : I don't have it yet, but I think a simple 10kohm resistor with a 0.1microF capacitor. This circuit is ONLY for development work, to develop the network analyser.
2) I have a vi (not finished though, I don't have the DAQ yet), generating a sinwave (see file attached), which will generate the AC component. Why can't I use this signal as an output signal? (my expertise in electronics is not huge, but growing...)
My idea was to send this signal to the DAQ. As it is for development work, I am choosing the simplest option possible.
- For the project, I have a load unit Agilent 6060B, and GPIB cable (to control the AC and DC compenent) of the current. And I will record current and voltage input with the DAQ card. Using the network analyser to have the frequencies with different amplitude, and generate nyquist.
Does this make sense to you?
01-05-2012 09:20 AM
I haven't purchased the DAQ yet, will next week btw, so, in case you think of something better than 6220, but in the same sort of price (development phase of the work), let me know
01-05-2012 10:39 AM
The Sound and Vibration Toolkit has the Example of a Swept SineFRF (DAQmx) is an example that can be used for this application. While under the Sound and Vibration toolkit exampls, this works with a DAQmx and has frequency limitis based on the sample rate (Nyquist Limit) for the DAQmx card. This can easily be modified to be used for a swept sive wave stimulus/response of a network analyzer and includes harmonic analysis and a couple other features.
01-09-2012 07:43 AM
Thanks for your post. With the PCI-6220 you will be able to read in the voltages from the RC circuit, however if you are planning to output your sinewave to your RC circuit from this 6220 card. You will not be able to as this particular card does not feature analog outputs. If you wish to output an analog signal from the National Instruments DAQ card, you could use the PCI-6221, which feature 2 analog outputs which can output at a maximum 833 KHz.
However if your AC component output is not coming from the National Instruments DAQ card, then the 6220 will work for you.
Let me know if you have any other questions.
03-01-2012 10:17 AM
Sorry for late update on that topic.
I am using the following vi from that toolkit. Is this a network analyzer or not?
You said that needed some modification, isn't it?