Hi César,
"In Simulink, there are some blocks, do not enable you to set the Sample time parameter by default. However, you can see and set the Sample time parameter for these blocks in an existing model if the sample time is set to a value other than the default of -1 (inherited sample time). The Sample time parameter is not available on certain blocks because specifying a sample time that is not -1 on blocks such as the Gain, Sum, n-D Lookup Table, Discrete Filter, Discrete FIR Filter, and Discrete Transfer Fcn causes sample rate transition to be implicitly mixed with block algorithms. This mixing can often lead to ambiguity and confusion in Simulink models."
However in the learning course, since it's inheriting the block parameter value is set to -1, hence it must be not be accepting your solution. As a workaround, for you to make this option visible you have to set this value to something other than -1.
You can do this from the Matlab Command window as follows:
- Select the "Discrete Transfer Fcn" block in Simulink window.
- Go to the MATLAB window and run the following command in the Command Window, to set the parameter.
set_param(gcb,'SampleTime','2');
Now you can double click the "Discrete Transfer Fcn" block, and you would see the field to change the SampleTime for the block.
You can find more information about this on the following documentation page.
Thanks
Gyan
