Simulink variable signal size

I am trying to implement a logic, were i would have a variable signal size data with me.

Whenver the simulink model is executed then the there would be new set of data received, this data either needs to be updated in the existing values in the variable size signal or needs to be appended to the existing variable signal size.

I am not sure quick how to acheive this, i tried using the below pattern, where newData is getting appended to the prevData, but it does not work, as to get the previous data i am using a delay block, which gives me error as the size of the delay block cannot be propogated. Here i am just appending the data without any condition, but ofcourse in the real world i would make sure that the DataOfInterest is having max bound of some number and not take newData later.

Answer 1

[Benjamin Thompson]

You cannot change the size of signals during a simulation run. That is what your MATLAB function is doing, trying to add new data on each function call.

[vivek patel]

Can you please explain then why in the sldemo_varsize_basic, we can use switch, so the size of the b is changing during a simulation run isn't it ? Then why it is okay but not what i am trying to do ? I think i am missing some silly thing when we say "size of signals during a simulation run" cannot be changed.