Modular Train Communication System
Railtec Systems GmbH, located in Hergiswil/Switzerland, specializes in providing services for transport enterprises and suppliers in all areas of control engineering and software development for rolling stock.
With introducing more and more multimedia services for customers and passengers in the transportation sector, demands on communication systems in trains are increasing, while the space available for electronics is often limited. In addition, many multimedia and void software packages are available for Linux and ix86 platforms. To satisfy the need for performance in demanding applications and to close the gap to commonly known ix86 platforms, SYS TEC electronic recently developed a 19" rack mountable communication platform. The system was optimized for use in rolling stock applications and comprises a CPU module, Backplane, Power Supply module as well as an I/O module. The system is EN50155 Class Tx compliant and allows for operation at temperatures from -40°C to +70°C without the need for active cooling. Besides the electronic design, heat management issues turned out to be challenging. Dedicated heat spreading and heat sinking concepts were developed and implemented to allow for a safe operation within the specified operating conditions.
The CPU Module is based on an ECUcore-E660 system on module with a 1.3GHz Intel Atom E660T MCU and a Linux Board Support Package. It features two Gigabit Ethernet ports, a CAN port, two RS485/RS422 ports, RS232 as well as USB. The module provides a basic memory configuration of 4 GiB on-board SSD and up to 2 GiB DDR2-800 SDRAM. A vibration protected microSD card slot and one lockable SATA port are available to extend the system with external mass storage configurations. The ECUcore-E660 was optimized for reliable operation in an industrial environment. A separate on-board system diagnostics controller on the ECUcore-E660 performs essential monitoring tasks, such as temperature surveillance and power-on management to ensure recovery from critical states, performs continuous supply voltage monitoring and provides a secondary watchdog timer.
The I/O Module provides 8 digital inputs, 2 fast counter inputs, 8 digital outputs and 2 analog inputs. All I/O channels are galvanically isolated and brought out on an industrial grade DIN 41612 compliant 48 pin block connector. The digital input and output channels support an ultra-wide range input voltage from 24V DC to 110V DC including user-configurable filtering options, reverse polarity and overload protection. The analog input channels support input signals types from ±10V, ±20mA, 0…10VDC and 0...20mA. Besides the I/O circuitry, comprehensive intelligent on-board diagnostic functions provide means for precise in-application failure detection, long term diagnostic surveillance and consistently ensure a reliable operation. The module's firmware is in-system upgradable via backplane. Thus, a system-wide firmware upgrade can be handled by the CPU module centrally without the need to remove any component from the rack. In applications that require a long system lifetime and typically come with short repair windows, these enhanced diagnostics and update functions are cutting-edge features to reduce the overall system downtime significantly.
The Power Supply Module is an intelligent digital ultra wide-range power supply that supports an input voltage range of 24V DC to 110V DC. It provides VME bus compliant to 5V DC and 12V DC voltage levels with up to 95W output power to the backplane. The module is based on a microcontroller-operated booster and a full-bridge converter. On-board buffer capacitors cover temporary power fail events for 10ms at full load. To ensure a clean system shutdown of the CPU module the PSU provides an output of 10 watts for further 250ms. VME-bus compliant signals as well as system-specific power fail event information are provided to the CPU module. Extensive on-board diagnostic circuitry continuously monitors the health status of the buffer capacitors as well as all voltage and current levels on the backplane. In addition, the CPU module can continuously monitor the system's power consumption for error detection or statistical purposes. An integrated inrush-current limitation, as well as over-current and over-voltage protection prevents the module from internal damage.
Although the developed modules can work with standard VME32 backplanes, their best performance is revealed with the Backplane that was developed specifically for this Train Communication System. It provides optimized heat-spreading and heat transfer characteristics and allows for use of standard VME power supply units. Multiple CANopen-based bus lines on the backplane support an extreme high level of flexibility and modularity regarding system structure and module placement within the rack.
SYS TEC electronic designed all modules for specifically for Railtec Systems. The serial production is scheduled at SYS TEC production facility in Reichenbach/Germany. All components are covered by the SYS TEC obsolescence management process.