Okay, some more work done shows I was wrong about the data format. Each frame in fact contains the sensorID (0 to 3) and the reading indicating distance to object. Works quite well, easy enough to decode.

My question is, can this type of an ultrasonic trasducer ( https://www.google.co.in/search?q=au...ient=firefox-a ) be used in an 24x7 application? In its native purpose, it would be used just a couple seconds each day. Would the transducer degrade/fail if its pinging all the time?