Although the most popular methods of travel in the United States are by air and by highway, the railway system continues to be an easy and relevant choice for shipping industrial products. When managing rail-based transportation, systems need to handle both local and long-distance travel, and must be reliable and easily-maintained. The maintenance process could be greatly simplified with a finely-tuned technology that can automatically report problems.

Traditionally, rail conditions were detected using sensors connected to I/O modules. The I/O modules transmitted the information over copper RS-485 connections to control centers hundreds of miles away. Twenty-five years ago, this method was considered very advanced, and it fulfilled the immediate needs at that time. After about ten years, however, the copper cables began to deteriorate as they approached the end of their shelf life. Transportation agencies began to upgrade their communication infrastructure with new fiber-optic glass cables and IP-based technology. For better scalability and expansion, legacy networks needed to be adapted to work with Ethernet networks.

System Requirements
The client wished to employ a large-scale IP-based management system. Every field event needed to be sent to an SNMP trap center for data logging. Sensors needed to be able to issue instant warnings to the control room, so staff could immediately take the appropriate action. To meet these requirements, each substation would need to rely on I/O modules with the following features:

• SNMP-enabled IP-based communication
• Ability to send instant warning messages

System Diagram

System Description
Many devices in the field were already IP-enabled and established remote connections to the control center over the client's existing network of microwave towers. For legacy devices that had no Ethernet functions, the client used ioLogik E2210 I/O servers to connect to the network. Each ioLogik was assigned its own IP address and accepted physical signals from the legacy device as digital inputs. SNMP was used to report status changes to IP-based hosts at the control center. Since Active Ethernet I/O made it possible to use a report-by- exception approach, precious bandwidth was saved. Configuration of the ioLogik was simple due to its user-friendly Click&Go interface, and it operated seamlessly within the railway's existing IP and SNMP architecture. Overall, the ioLogik made it easy and cost-effective to convert physical data from legacy devices into IP-based data.

Why Moxa
		Event-triggered I/O architecture
		Easy-to-use I/O design
		SNMP I/O
		Instant TCP messages

Conclusion
Active Ethernet I/O can be implemented with no programming and little or no technical training. Implementation time and effort is drastically reduced, resulting in higher productivity. The Active Ethernet I/O server enables automatic transmission of data when user-specified conditions are met, making programming easier. Users can also receive automatic reports of I/O events by SNMP, with data saved on the trap server. Projects can be completed in far less time and are much easier to maintain, modify, and expand.

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