Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: method name
OSC_BOOL_VALUE_METHOD_NAMEParameter: set
OSC_BOOL_VALUE_SET_METHOD_NAMEParameter: value
OSC_BOOL_VALUEParameter: value
OSC_BOOL_VALUE_PORT