my program in Simulink is consists of three key block: the first block is packet input in order to to read the data of sensors by the serial port, the second block is my command (eg backstepping),and the the third block is sending pWM signals to the motors by the serial port using the packet output block of the Simulink.

there is anyone who worked with method?I have some questions to ask ?

or maybe anyone who did some real experiment using simulink can help me more. 

thank you