To use input data in a Stateflow chart from other charts or Simulink blocks, the symbol (variable) for the data must be resolved as input data type. This can be done in the Symbols Pane of the Stateflow chart.
The issue you are facing is because of the typo ‘Previous_satge’ instead of ‘Previous_stage’. This would have created another symbol in the Symbols Pane and will be treated as another input to the chart with a default value of zero.
