Networking Solution for Rail Transit AFC (Automated Fare Collection) System

• The rail transit Automatic Fare Collection System (AFC) targets at the automatic processing of the whole course including fare selling, checking, billing, charging, statistics, classification and managing.
• Urban rail transit AFC is characterized by short construction cycle and long service hours, and it needs to run continuously, so it put forwards high demands for the running and maintenance capability of operators, and equipment quality of equipment manufacturers.
• Because of the special working environment of substations and the requirements of automatic system, the communication network in substation automation system must have fast real-time response capability, good electromagnetic compatibility, superb reliability and sound security features.
• The operating environment of rail transit system is very complicated, and equipments are scattered on the ground and underground. In some places, the system even operates in dust blowing or humid conditions, therefore the equipments need to be able to resist harsh working conditions and have high anti-interference capability.

Network Topology

• ISM 3018D series are used in the field to send data of automatic recharging machines and gates to the control center 
• ISM 3028U series are used in equipment room to form a redundant fiber ring, then gather the signals from the field and send them to the control center, therefore to realize fast and stable data collection

• ISM 3028U, modular rack mounting industrial Ethernet switch with 24+4G ports
• ISM 3018D, managed Gigabit industrial Ethernet switch with 18 ports

• InHand switch products are able to form a redundant fiber ring to safeguard communication reliability. When there’s a malfunction in the communication network, the network can switch smoothly to the redundant backup link. InSwitch ring protocol is international standard protocol ITU-T G.8032v2 based and highly compatible. InSwitch can hybrid network with equipments of other manufacturers, and its fast auto-recovery function enables a recovery time of whole ring for less than 5ms.
• InSwitch supports redundant power supply input, ensuring constant running of the system. When one power supply fails, the redundant power supply will be started to keep the whole system running. Meanwhile, multiple power supply status alarming functions are available, making the network maintenance easy.
• The industrial grade InSwitch is superbly reliable, and it can work steadily and reliably under different kinds of harsh environment. InSwitch has passed the industry’s highest level EMC test and qualified against IEC 61850-3 and state grid standard.
  - Operating temperature: -40~85 ℃
  - IP40 grade of protection
• The unique modular structure of ISM 3028U enables customers to flexibly choose and configure ports according to actual networking needs, and reduces capital cost for customers.
• InSwitch adopts aluminum alloy housing with fanless cooling technology, MTBF (Mean Time between Failures) reaches 35 years, adequately meeting the requirement of long term stability of network.
• InSwitch can work steadily in a relative humidity ranging 5% to 95%, and it is strongly resistant to the humid underground environment.