How do you create a set of user defined data vauues and input the vauues to a discrete state space module?

[hrh1818]

I have been trying to use the discrete state space module found in the Simulation Toolkit to duplicate results obtained with Matlab.  So, far the exercise has been rewarding.  However, I have not yet found a way to create a set of user defined values and input the values to a discrete state space module. If you have found a solution to this problem please pass it on?

Howard

[Barp]

Howard,

I am glad for your interest in using the Simulation Module. Just to be on the same page, what is the version of that you are using? Before LabVIEW 8.5, we had the Control Design Toolkit and the Simulation module separate as two different packages and now we merged creating the Control Design and Simulation Module 8.5.

If you have the old one, then you could create a Symbolic Transfer Function that you can parameterize like " a^2/(b/m*z%2+c)" where a, b, m , c are elements that you can modify. To create it as discrete, just enter a value of the sampling time. After that, you can use the "Discrete Transfer Function" to implement this.

Let me know if you need more assistant. If you provide me with the version that you have, I can send an example....

[hrh1818]

Barp,  Thank you for your reply.  I am using the Control and Simulation module that comes with  Version 8.5 of Labview.

After I asked my question I found a method to create a finite set of numerical values for use as input to a discrete state space simulation model.  The method uses a chain of unit delays and adders. The output of a unit delay is connected to one input of an adder and the output of an adder is connected to the input of the next unit delay in the chain. The output of the last adder in the chain is connected to the input of the discrete state space model.  The output of a discrete filter is connected to the input of the first unit delay in the chain and the output of a discrete filter is connected to the second input of each adder.  The input to each discrete filter is a numeric constant.  The discrete filters are configured as differentiators and will produce an impulse at their output.  The magnitude of the impulse is proportional to the numeric value applied to the input of a discrete filter.

I am also using a some what similar method to display the (n-1), (n-2), (n-3) ... numeric values of the  discrete state space model's output. The method consists of a chain of unit delays with a numeric indicator connected to the output of each unit delay.

These two methods are adequate for my purposes.  However, if you can suggest some methods that don't take up as much real estate in a block diagram please pass them on.

Thank you once again for your reply.

Howard