Ultrasonic sensor (Receive Transmitte R+T - two functions in one module)

I use the Ultrasonic sensor (Receive Transmitte R+T - two functions in one module),

[+] connect to the A0

[- ] connect to the GND

in the grasshopper I connect the timer[200ms] to the UNO Read,but the Signal of A0 did not response to the distence only had random value(0~150).

I have no idea what’s going on,plese help me. thanks very much~

This is the senser:

http://www.192.1.myday.com.tw/a_myday/product_description.php?apina...