Level 2 Matlab S-Function

Hello,

I am working with a Matlab S-Function and I have problem with the OutputPort vector size.

The following error is printed : ''attempt to assign a vector of width 4 to a vector of width 0 ''

The only way I have is the following synthaxe : "block.OutputPort(1).CurrentDimensions = block.InputPort(1).CurrentDimensions"

But my Input port has a width of 1.

I want to make OutputPort vector that has width of 4 independantly from the input. Can someone help me to find a solution ?