Reading Serial data from arduino? ( But reads wrong values)

Hi,

I am using an arduino for system identification, so i made some basic simulink process that sends voltage from arduino and reads voltage from arduino. So far the voltages i am sending out as a pwm are coming out fine ( i can read it from a multi-meter), but when i try to serial read i am reading noise and nothing useful. I have attached my file, one runs on arduino and other runs on host.

Can you please take a look into this and give me feedback as where i'am going wrong.