Hello,
To my understanding it looks like you are trying to feed an array to stateflow input. The array when fed to a stateflow fiagram will result in an boolean array.
For example
SOC=[20 40 60 120];
ans= SOC >= 40
The output will be [0 1 1 1] rather 1 or 0. That is why you are getting this error. You need to make the stateflow input a scaler with respect to time steps.
Hope it helps
