How can I use FRD objects with the LTI System block in Simulink 7.9 (R2012a)?

I have converted a Simulink 7.9 (R2012a) model to an FRD object using the FRESTIMATE command. I would then like to use this object in an LTI System block (or equivalent) back in Simulink for part of a simulation.

Is this possible?

Answer 1

[MathWorks Support Team]

The LTI System block only supports SS, TF and ZPK objects because these are time-domain objects and Simulink is a time-domain simulator. FRD objects, which are in the frequency domain, therefore are not compatible with Simulink.

The best way to work with FRD objects is to use the System Identification Toolbox to estimate time-domain systems for these FRD objects. The following examples describe how this can be done:

 <http://www.mathworks.com/help/releases/R2014a/ident/examples/index.html>