Why does DLINMOD return an error regarding the C2D function in Simulink 6.1 (R14SP1)?

When the DLINMOD function is used to linearize a model in Simulink, it sometimes returns an error. For example running the following code:

   [a b c d]=dlinmod('testmdl')

Leads to the following error:

 ??? Error using ==> dlinmod

 Error using ==> get_param

 Error in 'testmdl/Subsystem': Initialization commands cannot be evaluated.  MATLAB error message: Error using ==> simulink\private\c2d

 Not enough input arguments.

Answer 1

[MathWorks Support Team]

There is a bug in Simulink 6.1 (R14SP1) that causes the DLINMOD to produce an error in certain situations.

The error is generated because DLINMOD calls the private C2D function instead of the LTI object functions such as SS and TF.

There are three things you can do to work around the issue:

1. Make sure the initialization section of the mask is properly set.

     Initialization section can be reached by right-clicking on the subsystem, then click on      view mask and go to Initialization tab.

2. Use the LINEARIZATION function in the Simulink Control Design.

3. Use the Simulink model discretizer.