Is it possible to recognise and record the amplitude values from a signal??

Is there any function in MATLAB code or a block in Simulink which could recognise and display the amplitude values of a signal?

[Walter Roberson]

Would this just be like directing the signal to a scope? Signals in Simulink basically _are_ just amplitude values (with some timing information attached.)

[Lakshman]

Scope just displays the amplitude plot from which we need to observe amplitude values at different time intervals. But what I need is a block which identifies and records the amplitude values at different time intervals on itself when a analog or discrete signal is fed to it as input. These recorded values are to be fed to further blocks of my simulink model as input for some processing.

Answer 1

[Johnston]

Can you be more specific Mr.Lakshman? Do you know the signal which you give as an input... and do u want to implement it in MATLAB or simulink?

[Lakshman]

Sir, I need to recognize and record the amplitude values of a (any)signal at some random points of time, so that I could feed those values to the further blocks of my simulink model which gives an estimate of the whole signal that I'm actually applying. A minimum of two amplitude values are to be recorded.

[Johnston]

Ok. There is Data Acquisition toolbox in MATLAB/Simulink with which you can perform such operations like acquiring and extracting. This might be helpful to you. Try this out once.

[Lakshman]

Thanks for the information, but as far as my knowledge Data Acquisition Toolbox could be used only to acquire data from hardware. I need to perform the same only in simulink without using any external hardware.

Answer 2

[Walter Roberson]

That sounds sort of like a Buffer Block.

Or perhaps what you want is Data Logging? http://www.mathworks.com/help/toolbox/physmod/simscape/ug/bsgpq8n.html

http://blogs.mathworks.com/pick/2011/04/08/log-and-inspect-simulink-data-quickly-with-simlog/

[Johnston]

Data Logging is to display the data. But Mr.lakshman wants to record and feed the same data as input. Can that be done using Data Logging?

[Walter Roberson]

I am not certain. I have read some postings about Data Logging in passing, but I have never worked with it myself. I have had the _impression_ that logged data can be recalled and used later, in some configurations.

Perhaps would would be appropriate would be something like using a triggered subsystem around a buffer. Or is that not suitable for analog signals? On the other hand, the bit about "recognizing" the signals is hinting to me that if an analog signal is fed in, then an A/D convertor-equivalent to "read" the signal would be suitable; the then-digital signal could be buffered.