Some model parameters may be accessible in the connection manager and may be tunable in the desktop simulation case (i.e. when the model is running in Simulink) but NOT tunable in the real-time code. This results from how the Mathwork's Realtime Workshop generates its C code. Generally, parameters that are not tunable in RTW generated code are parameters that are not used directly in the C code; such a parameter is operated on at code generation time to produce a secondary item that is actually used in the C code.
