Hello, Navin.
Welcome to the forum.
The Maestro does not support changing channel modes through TTL serial commands or the script commands. Also, please note that the Maestro accepts digital or analog 0V to 5V signals, and some ultrasonic sensors (like the Parallax PING))) Sensor) output variable width pulses, which the Maestro cannot read directly.
If you are trying to use an ultrasonic sensor that does not have a simple digital or analog output, another forum member posted about his solution for using the HC-SR04 range finder with the Maestro (that involved a simple low-pass RC filter) that you might find helpful. If you are looking for an ultrasonic sensor that has a more appropriate signal that the Maestro can handle directly, you might consider the Maxbotix sensors found in the “Sonar Range Finders” section of our website
-Brandon