setting step size for time response analysis

[bunnykins]

Hi NI Discussion Forums,

I am trying to configure or set the step size in Control Design (CD) Parameteric Time Response.vi for a step input size to be 40u(t) i.e. 40/s.  I have spent a lot of time searching the NI.com website, forums, etc. as well as consulting the supplied LabVIEW Control Design Toolkit User Manual however I cannot see how this is achieved and cannot see any examples other than accepting the unit (1) step size.  I also tried another method by attempting to multiply the system Closed-Loop Transfer Function (CLTF) with another TF (representing the input step signal) of 40/s and to then plot the time response however this wouldn't work due to mismatches in the signal (source/sink) types.

If anyone can assist or point me in the right direction it would be greatly appreciated.  Attached vi for reference.

Regards,

[Barp]

Since the model is linear, you can easily just scale the output signal with the specific offset and input gain. Here is the code that you could use:

On the other hand, if you are trying to get a more realistic simulation, I would suggest to use the "Control and Simulation Loop" and use step response in there. We allow you to use any step size. Also you can use the the "saturation" function between controller and plant to verify a more realistic control signal.

[RavensFan]

Barp,

Your image doesn't show up.

It points to http://nitalk.natinst.com/servlet/JiveServlet/showImage/102-11135-1-3387/Untitled.png which I bet that only NI employees have access to taht server.

[Barp]

ok... sorry for that... hopefully the snippet will even make it faster to drop on your code...