DETECTION
Devises used to recognize a locomotive or car is located or occupy a specific section of the railroad. Used for signaling, dispatching, grade crossing operation, turnout operation or any use needed to locate trains.
SIGNALING
Signaling devices and control systems like detection, manual or automatic. 
WHAT IS DIGITRAX TRANSPONDING?
* Proven technology for bi-directional layout control without the need for modifications to your existing DCC system investment.
* Know the detection section and/or zone location and identification of any specific locomotive or other rolling stock equipped with a transponding device. Yes, now your dispatcher will be able to know "who you are and where you are"!
* Data received by the system from mobile decoders can be used for display, automation, sound processing and much more.
* Transponding allows you to automate staging yards and other operations.
* You can use Transponding devices in rolling stock in conjunction with transponding detectors on industry tracks to display the location of your freight cars.