System Introduction
With the rapid economic development in recent years, rail transit, as an important component of urban traffic system is developing very fast. Urban rail transit is a kind of safe, comfortable, rapid, punctual, environmentally-friendly transportation with high passenger carrying capacity. EVOC industrial PCs are widely used in the applications of PIDS (Passenger Information and Direction System), AFC (Automatic Fare Collection), Main Control, Carriage Surveillance and so on. Among them, AFC system is the most important component, representing the informatization level of rail transit.

AFC Components
Based on computing, communication, networking and automation technology, AFC is a system which realizes automation of the whole process including ticket vending, ticket checking, fare calculation, fare collection, statistics, clearing, management and so on. Such AFC systems have been highly developed and widely applied for urban rail transit. Smart cards can be widely used in the traffic system.

The AFC system comprises five hierarchical levels, i.e., tickets, terminal equipment of the station, computer system of the station, central computer system and clearing system. This hierarchical structure is divided according to the characteristics of rail transit. The functions of and requirements on each level are described as follows:

The 1st Level: The ticket is the proof of payment held by the passenger. The physical properties, electrical specifications, file organization and safety mechanism are stipulated for prepaid cards and single tickets.

The 2nd Level: Terminal equipment is installed in each station hall and provides ticketing service to passengers. The technical requirements for terminal equipment and its operation are stipulated for this level.

The 3rd Level: The main function of the station computer system is to monitor the status of the terminal equipment on the 2nd level and acquire the ticketing data and audit data of the station. The technical requirements for system data management, operation management and system maintenance are stipulated for this level.

The 4th Level: The main function of the railway line central computer system is to acquire the ticketing data and audit data of the AFC system of this railway line, and transmit the data to the clearing system of the urban rail transit for reconciliation. The technical requirements for ticketing management, operation management and system maintenance are stipulated for this level. The 5th Level: The main function of the clearing system is to unify all the operating parameters of the AFC system, acquire ticketing data and audit data of the AFC system for clearing and reconciliation, and connect the AFC system to the smart card clearing system. The technical requirements for ticketing management, operation management and system maintenance are stipulated for this level.

System Principle
The AFC system is a total solution integrating automatic charging, settlement and account sharing. EVOC industrial PCs are primarily used in Automatic Gate Machine (AGM) and Ticket Vending Machine (TVM). Multiple serial ports are required in AGM system, including ticket entrance, contactless IC card, message screen, block controller, central controller and alarm. Network interfaces, USB interfaces and system terminals are also needed for information communication.

Multiple serial ports are required in AGM system including ticket entrance, contact-free IC card, screen for messages, controller for block equipment, central controller and alarm. LAN ports, USB interfaces and system terminals are also needed for information communication.

System Configuration
1) Ticket Vending Machine: ERC-1004
2) Ticket Checking Gate: MEC-5006

Summary
As metro and light rails are developing very fast across the world, the AFC system is highly recommended for the transformation of rail transit systems into automated and information-based ones.