Subways have been one of the main transportation arteries of major cities for many years, and creating automated subways is a key part of keeping this type of mass transportation system running smoothly. In order to cope with the huge volume of passengers, it is essential to automate the traditionally manual operations of ticket vending, collecting, and validation.

The company highlighted in this story uses a Unix-Ware PC that is installed with MOXA C218Turbo and connection option Opt8J to connect each entrance and exit gate with an RS-485 communication interface. Ticket validation is done automatically when the passenger inserts a ticket into the slot at the gate. The computer, located in the central control room, uses the information stored on the ticket to calculate the distance traveled and corresponding fare in real time, and then instructs the gate to open and let the passenger pass, or remain closed and sound an alarm for assistance.