Error:Error in port widths or dimensions. Output port 1 of '<hidde​n_inserted​_signal_sp​ecificatio​n_block&gt​;' is a one dimensional vector with 1 elements.

Answer 1

[Shlok]

Hi Pratik,

I get that you're running into an error about port widths or dimensions. This usually happens when there's a mismatch between signal dimensions such as feeding a vector into a block that expects a scalar. In your model, the "Mux" block is outputting a 1×3 vector by combining three scalar signals, but the downstream block appears to expect a scalar or a 1×1 signal. Simulink tries to resolve this mismatch automatically by inserting a hidden signal specification block, but in this case, it fails, leading to the error.

To fix this issue, you can:

• Modify the downstream block to accept a 3-element vector, if that’s the intended behavior.
• Use arithmetic or logical expressions to compute a single scalar output instead of combining all signals into a vector.

Refer to the following MATLAB Answer to learn more about the error involving a hidden signal specification block:

https://www.mathworks.com/matlabcentral/answers/452574-why-do-i-get-an-error-about-hidden-signal-specification-block-and-signal-object-properties-in-simu