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Versatile, Durable, and Extendable Train Systems


On mainline passenger trains, train computers must support a wide variety of automated services and applications over a widely distributed infrastructure. Taken together, communications with wayside stations and control centers, Wi-Fi access and services for passengers, NVR/CCTV, operator logistics, and passenger ticketing subsystems are all as likely as the other to be found on any mainline passenger train, making versatility, modular extensibility, and serial-to-Ethernet optimization key features for a master train computer.

Because these ancillary services do not serve the vital role that automated signaling and control systems do, their engineering may be more loosely applied. Nevertheless, with the harsh vibrations, power fluctuations/EMI, and potential for wide temperature extremes, strict engineering standards cannot be neglected. Hardware and software reliability are foremost concerns. Train computers have specific requirements, and among those are versatility, durability, and extensibility.

Power Centralization

As the EN 50155 standard indicates, computer hardware for mainline trains require strongly engineered EMI protection against both intermittent failures and power surges. The standard sets protections that represent the absolute minimum any computer should meet before being considered for use on a train. The first thing to look for in a train computer is EN 50155 compliance.

Yet these power features are internal; what the standard does not take into account is that externally, these computers form nodes in a system distributed across the entire train consist. Every carriage will likely be equipped with its own computer cabinet, and these may include a wide variety of IT and IA devices. Consequently, without a consolidated power control, shutting down a full mainline train system would be a burdensome and time consuming process of going into every car, opening the cabinets, and powering down the stations (and perhaps even devices) one by one.

Power redundancy and centralized controls are therefore important features for on-board systems, particularly in a mainline train. Basic consolidation of control may be achieved by means of I/O switches linked over a serial interface; however, where universal power supplies (UPS) may be used, a superior solution is available. By pairing cabinets with a UPS, the train computer may be configured (again using its serial interface) to receive instructions from the UPS about when shutdowns and powering up should be initiated. In that way, whenever central power is cut—whether because of system failure or operator commands— the UPS will be available to maintain the power status as it initiates a safe shutdown procedure. Indeed, using SNMP or a control logic, it is a relatively simple matter to set up graded, intelligent responses to a variety of power events.

Stock TC-6110 train computers are compliant with the strictest EN 50155 EMC requirements, and ship with an independent power interface for configuring remote power controls. All models are fanless designs with conformal coating, and feature the SafeGuard™ suite of hardware and software optimizations for strong protection against temperature and vibration extremes.

Communications Systems

Outside of signaling and control systems, the first responsibility for computers aboard mainline trains will be to maintain communications links with the control center and wayside stations. Both cellular and Wi-Fi modules will be imperative.

Additionally, however, cellular or Wi-Fi trunking may be required to provide adequate bandwidth and reliable wireless services to their passengers. Thus, modular extensibility of wireless connectivity is an important feature.

Stock models of the TC-6110 all ship with built-in GPS and Wi-Fi modules. Extension modules adding Wi-Fi and 3G clients will be released soon.

Passenger Logistics

Passenger logistics and accounting is a cornerstone of automated passenger trains; it encompasses a potentially huge class of subsystems that may involve CCTV, card readers, Wi-Fi (both WAN and LAN), cellular clients, localized automation, passenger analysis software, and passenger safety applications. Some of these subsystems will involve intricate software suites that integrate video, audio, RFID, Wi-Fi, 3G, and perhaps also more traditional automation interfaces such as serial, or digital I/O. Passenger ticketing systems, for instance, may range from the extremely simple—involving little more than a database and a human intermediary—to the very complex, integrating fully automated wireless systems that reference or track RFID cards and communicating in real time with the remote control center. To ensure reliability and security, a powerful, modularized base system that can be easily extended to serve a variety of IA and IT interfaces is a core requirement.

The TC-6110 features a total of 7 standard interfaces including serial, USB 2.0, and Ethernet.

Video Systems: CCTV and NVR

On-board video systems complement both passenger and operator logistics, and serve such an important role that they must be considered independently. An NVR system for a long-haul train will need to be capable of managing scores of CCTV stations (both external and internal), and must be capable of integrating this data with security systems, sensors, and automated alarms and controls. To handle the huge bandwidth that video data creates, a strong, fast CPU with access to large storage media and a high speed network will be needed. To protect these storage devices, strong anti-vibration measures like shock absorbers, vibration sensors, and custom software applications will be required to protect against environmental strain.

A stock TC-6110 train computer ships with an Intel Atom D525 1.8GHz CPU and two storage modules, each accepting up to two 2.5” SATA storage drives. Combine the TC-6110 with the MxNVR-N04 NVR system and our EN 50155 certified VPort cameras to build a fully EN 50155 certified on-board CCTV system. If more storage space is needed, additional drives may be added using the TC-6110’s extension slots.

Operator Logistics

As train automation shrinks crews to fewer and fewer members, the need for centralized operator control and awareness of onboard logistical issues grows. Operator logistics will be wholly distinct from the information gathering and analysis involved in passenger logistics. These operations subsystems will employ both independent and integrated hardware and software, possibly monitoring things like plumbing and HVAC systems; intrusion detection and network tools for IA and IT systems; the stock taking of vended supplies like food, reading materials, souvenirs, and other knick-knacks; potable and non-potable water supplies; crew schedules and information services; the ticketing system backend; plumbing, lighting and electrical monitoring; and so forth. These services, sensors, and actuators, so distributed throughout the train, will require a control application through which they may all be conveniently monitored and maintained.

Moxa offers a full line of EN-50155 I/O and gateway devices that may be integrated with the TC-6110 to provide optimized train computing systems; these include the NPort 5000AI series of serial-to-Ethernet gateways, the modular ioPAC 8020 RTU controller, and the ioLogik E1500 series of remote I/O devices.

Passenger Infotainment

One of the key systems that has become a requirement on every current long-haul, mainline passenger train is a passenger information and entertainment system. These systems vary widely, and can incorporate public screens, private in-the-seat screens, and digital signage like carriage marquees or scrolling LED/LCD screens that inform or remind passengers of arrival/departure times, delays, weather conditions, and other events of interest. These systems may also serve passengers with links to the train crew, internet connections, or entertainment like movies, music, and games. For long-haul trains, these systems will need to be built to serve highly available, high-bandwidth connectivity with security measures strong enough to support monetary transactions.

Moxa’s TN series of EN 50155 train-optimized switches feature PoE+, Gigabit fiber interfaces, and a wide range of port densities. Match them with the TC-6110 train computer to build high speed, highly available networks to securely deliver passenger entertainment and information at lightning fast speeds.

Generally speaking, while mainline train systems do require significantly higher durability standards relative to commercial systems, because of their distributed architecture and relatively mild operating environments the hardware requirements are less strict than for other trains. The biggest challenge that computers on long haul passenger trains will need to address are the extensive software and automation subsystems they must manage or integrate, and the consolidation and centralization of operator controls. Extensibility and reliability are the keys to effective train systems, with EN 50155 certification representing the bare minimum operators should ask for.

To read more about the requirements for auxiliary automation computers on board trains, download our white paper, Engineering One Computing Platform for Any Class of Train. For a quick summary and an overview of how Moxa SafeGuard technology suite brings value and security to NVRs and other train automation platforms, visit our latest train computing microsite. To learn more about Moxa’s entire line of EN 50155 approved rail products, visit our new Railway Solutions site.

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