From the information given there could be a few possibilities for the error. More information is needed but here are a couple things to investigate:
- The Target_Ratio1 "signal" is unnamed in the model. Target_Ratio1:1 is a synthetic name created by concatenating block name with port index (BlockName:1, for example). This is Simulink's naming convention for unnamed signals.
- The Excel sheet specifies Target_Ratio1 as the signal name (which doesn't match the empty signal name in the model) in the top row of the sheet
- 2 workarounds: 1. Name signal in model to be the same name as the block, or 2. Update name in Excel sheet to include the port index. The top row would change from ["Target_Ratio1", "Actual_veh_spd"] to ["Target_Ratio1:1", "Actual_veh_spd:1"]
