Parallax PING Ultrasonic Sensor with a Siemens S7-1200 PLC

I am trying to configure a PLC ultrasonic sensor with a PLC. The problem is that I have to send a pulse that is 10us in length to start it, but I have to receive the pulse through the same wire. Has anyone done or know of a way to achieve this?

What did they say at the Siemens S7-1200 PLC forum?
(apart from "we can't guarantee our code is Stuxnet-proof")