Specify that an input port expects zero-based indices
void ssSetZeroBasedIndexInputPort(SimStruct *S, int_T pIdx)
Use this macro in mdlInitializeSizes to specify that port pIdx expects zero-based index values. By setting this macro, the Simulink® engine runs a diagnostic when it updates the diagram to check if the S-function input port expecting zero-based indices is connected to a block that is producing one-based indices. The engine signals an error if it detects that the signal connected to this block is one-based. Simulink blocks that can produce indices include the For Iterator and S-function blocks. If neither this macro nor ssSetOneBasedIndexInputPort is invoked, The engine does not run this diagnostic, even if the input port is connected to a block that produces indices.