Discrete to continuous- Problem with signal dimensions

Hello:

I had a system being simulated as discrete. Now I have changed every discrete operator (derivatives, integrals and so on) to continuous ones but some error have appeared with no clue to solve:

Error in port widths or dimensions. Invalid dimension has been specified for output port 2 of ....

Some blocks have the dimension of the input signals ok but it reaches a point in the diagram where some question marks appear as it does not recognize it. I have not changed anything except discrete operators.

Could the memory blocks be the problem?

Thank you in advance

[Kaustubha Govind]

Which block is the error coming from, and what are the input dimensions to it?

[Javier Guiterrez]

It is a demux block that was working perfectly in previous simulations. It has 1 input signal and 4 output signals.

[Kaustubha Govind]

What is the second output of the block connected to? Perhaps that block (or one of its downstream blocks) is telling the Demux block that it needs a signal size that is not possible. Simulink determines this by performing back-propagation.

Answer 1

[Kaustubha Govind]

I would recommend replacing the connection to the block connected to the second output of the Demux block with something like an Inport block. Then turn on Format>Port/Signal Displays>Signal Dimensions, and update your model (Ctrl+D) - see what dimensions the downstream blocks are expecting. Does this signal dimension make sense as an output of the Demux block?