Numeric Operations with transfer functions

[shank]

hi sir,
    sorry for the late reply but was on a short vaccation. yes i am doing it as a biomedical research. we dont need DAQ as such now , but maybe in future if we plan to do it online. also i did combione both the pages but now its giving some error. i dont know what it is. can you plese loook into this. i am ttaching u the complete one.

[shank]

i hope you will surely have a solution for this. plese help me with it.

thank you alot.

[Barp]

Shank,

The problem that you have is related to a parameter inside the "delay" block. You need to provide a "max delay" equal or bigger than the value you have. If you do that, you should be able to start the simulation.

However, on my side, I noticed that you lookup tables on the right side of your simulation are all quadratic and default. If you to run this simulation, it won't give you results consistent. You have to enter the correct values, otherwise the solver won't be able to integrate this simulation.

Hope this helps!

[shank]

yes. i noticed that now. i am ataching one with all the filled in values. maybe you can have a look now. sorry for the wrong one.

[shank]

Also i want to give the Sresp signal from the values i have and not from the signal generator, how to do that so that the simulation runs properly. i am attaching the file, you can open it in notepad.only important is the time and the values , the phase isnt so much important. how to make this work?

[shank]

sorry the file isnt attaching, but it is a xml doc. with 2 columns, time n amplitude basically. how to introduce an array for a fixed time then in this vi?

[shank]

hi
 i have modified my vi and now i am trying to read data from the ascii files i have. it shows properly the waveform when i configure the load ascii vi, but when i run the vi it gives 0 at the output. what must be the problem or is it that i am reading the data wrongly. i am attaching the vi, can anybody please help me with it.

[Barp]

Shank,

The problem is that inside the simulation loop, you have to treat each element as an execution point-by-point. The way you have right now, you will read the file each time the simulation does one step forward.

To fix that, just move the "Load from ASCII" block outside the simulation loop. After that, you have to access the Waveform datatype correctly and you can do that with the "indexer", in the "Simulation>>Utilities" pallette. This VI will read the waveform and will try to obtain each point accordingly.

Here is the picture of what I am trying to say.

Additional to that, notice that you should not have a vector (1D array) as wires. Please try to remove them since they were converted because you wired the waveform to the input.

Let me know if I was not clear...

Message Edited by Barp on 10-24-2007 08:36 AM

[shank]

thanks a lot for that tip. also it gives a error : -
"LabVIEW Simulation Module:  The ODE solver cannot meet the error tolerance using the minimum step size."
I want to adjust the minimum, maximum, initial step size and also the absolute tolerance to auto, but i could not find it. can you please help me with this. how to make them auto?
thanks once again for the help.

[shank]

also, is there any option to give initial values and desired values to a transfer function, as you can see in the block diagram attached earlier. also can you igure out what this integrator value is actually? i think it is the initial condition. but just want to confirm it with you.