Arduino UNO R3 Data Type and Simulink via MATLAb 2012a

Hello everybody in forum, I am getting a problem for Arduino UNO R3 in combine with ADXL335 accelerometer to make simulink block in Matlab 2012a. For example, I have used Arduino Analog Input block and run it. The command was showing that the model downloaded successfully. Now my question is, did i able to read the Arduino UNO board? If yes means what should I do now? Please guide me any of you. Also another question is, how should i calibrate G value from the output data if data type is unit8 (49 51 53)?

rgds Anam