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31-513: The MVB connects individual nodes within a vehicle or closed train set. Unlike the WTB, there is no single connector standard for the MVB – instead, there are 3 defined media and connector classes: The plugs and sockets are the same as used by Profibus , with 2 x DE-9 sockets per device. For OGF, the media sources are connected by repeaters (signal generators) being joined on a central star coupler. A repeater

62-539: A Manchester II code and a HDLC frame protocol with proper voltage balancing to avoid DC components in the galvanic isolation transformers. The Manchester decoder uses a phase/quadrature demodulation (not RS-485 , that operates with zero-crossings) which allows to span 750 m under worst-case conditions, especially when only the two extremity vehicles are equipped, as is the case with multiple traction for freight trains. No repeaters are foreseen since vehicles in between can have discharged batteries. A unique property of

93-716: A car radio was likely the only electronic device in an automobile, but now almost every component of the vehicle has some electronic feature. Typical electronic modules on today's vehicles include the Engine Control Unit (ECU), the Transmission Control Unit (TCU), the Anti-lock Braking System (ABS) and body control modules (BCM). An electronic control module typically gets its input from sensors (speed, temperature, pressure, etc.) that it uses in its computation. Various actuators are used to enforce

124-622: A bus is simply a device that connects multiple electrical or electronic devices together. Special requirements for vehicle control such as assurance of message delivery, of non-conflicting messages, of minimum time of delivery, of low cost, and of EMF noise resilience, as well as redundant routing and other characteristics mandate the use of less common networking protocols. Protocols include Controller Area Network (CAN), Local Interconnect Network (LIN) and others. Conventional computer networking technologies (such as Ethernet and TCP/IP ) are rarely used, except in aircraft, where implementations of

155-517: A duplicated shielded twisted pair cable, which runs in the UIC cables between the vehicles. The connector between the vehicles is the 18-pole UIC connector. Since connectors are exposed and can oxidize, a current pulse is applied at connection establishment to evaporate the oxide layer , called fritting . The standard connector for the WTB nodes is a DIN 9 pin connector. The physical level uses RS-485 levels at 1 Mbit/s data rate . The encoding uses

186-399: A sequential address. Vehicles without WTB node ("c onduction vehicles ") are not counted. The frames have a maximum payload of 1024 bits. The WTB operates cyclically to provide deterministic operation, with a period of 25 ms, used mainly for the traction control. The WTB also supports sporadic data transmission for diagnostics. The content of the periodic and sporadic frames is governed by

217-581: A very similar behavior in respect to the application. Despite the similarities, no rail-manufacturer has considered FlexRay , since they valuated a common solution higher than a multitude of better busses. Conversely, in 1999, the automotive industry evaluated MVB (in an extended 24 Mbit/s version), but dropped it because of the costs, which should be unreasonably low for the mass-market of millions of vehicles. The wire train bus has been designed for international passenger trains with variable composition, consisting of up to 22 vehicles. The medium consists of

248-469: Is also used for the transition between mediums. There is no inauguration, the addresses are statically allocated. The number of addressable devices depends on the configuration of the vehicle bus – there may be up to 4095 simple sensors / actuators (Class I) and up to 255 programmable stations (Class 2, with configuration slots). The physical level is using transmissions at a 1.5 Mbit/s data rate using Manchester II encoding . The maximum distance

279-605: Is being introduced into train sets (according to the EN 50155 profile). Still all the alternate vehicle buses are connected to the Wire Train Bus. MVB is similar to FlexRay , both have the "process data", which is called "static segment" in FlexRay , and "message data", which is the "dynamic segment" and are driven by a fixed TDMA scheme. Running FlexRay with 2.5 Mbit, an RS-485 physical layer and only one "coldstarter" would lead to

310-482: Is determined on the restriction of a maximum allowed reply delay of 42.7 μs (where for longer distances a second mode is used that allows up to 83.4 μs with reduced throughput, in case MVB is used for switchgear on the track side) while most system parts communicate with a response time of a typical 10 μs. MVB was derived from the P215 bus developed by Brown Boveri Cie , Switzerland (now ABB ), incorporating

341-518: Is not due to the communication technology: most devices implement the MVB protocol machine in a small area of an FPGA which is today anyhow present, and the costliest component remains the connector. But railways certification is costly and not always needed for uncritical applications such as comfort and passenger information . When total cost of ownership is considered, the cost of the hardware elements can easily be outweighed by additional engineering costs in

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372-642: Is possible). The paradox situation is that the IEC 61158 field bus and MVB physical layer were developed by the same persons in IEC TC 57 . The difference came from the fieldbus physical layer which assumes a phase-locked loop to decode the Manchester data, requiring a preamble to synthonize the decoder, while MVB operated principally with optical fibres where this method is useless, MVB's decoding relies on zero-crossing detectors and Manchester pattern recognition. However most of

403-786: The ARINC 664 such as the Avionics Full-Duplex Switched Ethernet are used. Aircraft that use Avionics Full-Duplex Switched Ethernet (AFDX) include the Boeing 787 , the Airbus A400M and the Airbus A380 . Trains commonly use Ethernet Consist Network (ECN). All cars sold in the United States since 1996 are required to have an On-Board Diagnostics connector, for access to the car's electronic controllers. The main driving forces for

434-537: The UIC 556 standard. Since frame size is limited, a version of TCP with reduced overhead was used for message segmenting and reassembly, that at the same time allows to cope with changes in composition, called RTP ( Real-Time Protocol ). The WTB was derived from the German DIN bus developed by ABB Henschel (now Bombardier ). It benefited from the phase/quadrature decoding provided by Italy and from an improved train inauguration provided by Switzerland , based on

465-465: The publisher/subscriber principle from early field busses ( DATRAS ). Back in 1984, IEC TC 57 defined the requirement specifications for busses to be used in electrical substation in collaboration with IEC SC65C . MVB presents many similarities with the FIP field bus (originally from French " Flux d'Information vers le Processus ", relabeled as Factory Instrumentation Protocol or some references also use

496-549: The Phase/Quadrature decoding was used instead. The TCN is used in most of the modern train control systems usually connecting the vehicles with an 18-pin UIC 558 , including: IEC 61375 is a suite of standards. The contents of the corrigendum of December 2015 and October 2016 have been included in this copy. a) select the wireless network on the basis of QoS parameters requested by the application; b) allow TCMS and/or OMTS applications, installed on-board and communicating on

527-411: The WTB is the train inauguration (In German: Zugtaufe ) in which the newly connected vehicles receive an address in sequence and can identify the vehicle side (called port and starboard like in the marine) so that doors open on the correct side. Up to 32 addresses can be dynamically allocated. When two train compositions join, the addresses are reallocated to form a new composition of vehicles with

558-407: The actions determined by the module (turn the cooling fan on, change gear, etc.). The modules need to exchange data among themselves during the normal operation of the vehicle. For example, the engine needs to tell the transmission what the engine speed is, and the transmission needs to tell other modules when a gear shift occurs. This need to exchange data quickly and reliably led to the development of

589-573: The development of vehicle network technology have been the advances made in the electronics industry in general and government regulations imposed, especially in the United States, in order to make the automobiles environmentally friendly. With stringent emission standards for automobiles, it became impossible to attain the required degree of control without the help of on-board computing devices. On-board electronic devices have also contributed substantially to vehicle performance, occupant comfort, ease of manufacture and cost effectiveness. At one time,

620-594: The experience with the FSK multiple traction bus of ABB Secheron , Geneva used in the SBB freight trains . The physical layer of WTB shows similarities with the WorldFIP field bus ( EN 50170 part 4 ) - its "voltage mode" did use 1 Mbit/s and a maximum of 32 stations on the bus with a maximum length of 750 meters, the use of FIP transceivers was studied early in the TCN evaluation, but

651-527: The hybrid "Flux Information Protocol") that was developed in the French NFC 46602 standard series . Since both stemmed from the same IEC TC 57 specifications. This explains why MVB and FIP have similar operation (cyclic and event-driven), only the arbitration method in case of multiple access differs, as MVB used a binary bisection mode relying of collision detection while FIP piggy-backed a "look-at-me" bit over periodic data. Efforts to merge FIP and MVB failed at

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682-550: The modern development and test equipment can equally communicate WTB/MVB frames as well as Profibus frames on the line as the telegram structure similar to Profibus . The WorldFIP connectors found usage in train equipment in France and North America (by Bombardier ) until a joined effort on a common UIC train bus was started (with Siemens and other industry partners) that led to the WTB/MVB standard in late 1999. The MVB standard

713-538: The on-board communication network, to have a remote access to applications running on ground installations; c) allow applications running on ground installations to have a remote access to the TCMS and/or OMTS applications installed on-board. Vehicle bus A vehicle bus is a specialized internal communications network that interconnects components inside a vehicle (e.g., automobile, bus, train, industrial or agricultural vehicle, ship, or aircraft). In electronics,

744-445: The other modules as necessary, using a standard protocol , over the vehicle network. Networks were not new, but their application to the vehicle was. The networks for the vehicles called for: Although the vehicle network made modest demands on data throughput , the demand for more on-board computing is continuing to drive changes to these networks to provide higher-speed communication between modules. The control area network include

775-590: The railways market with its small series. In the USA , the IEEE RTVISC evaluated both MVB and LON as vehicle and train bus. The IEEE finally decided to standardize both in IEEE 1374 , with a clear separation of tasks: Additionally more and more components are added to rail vehicles that need far more bandwidth than any field bus can provide (e.g. for video surveillance ), so switched Ethernet IEEE 802.3 with 100 Mbit/s

806-676: The receiver and transmitter for the host to controller transmission and interlinking between the computers There are several network types and protocols used in vehicles by various manufactures. Many companies are encouraging a standard communication protocol, but one has not been settled on. Common vehicle buses protocols include: Some examples of physical transmission media use in vehicle networks: Additionally, many major car manufacturers use their own proprietary vehicle bus standards, or overlay proprietary messages over open protocols such as CAN. Commercial class vehicles have Type-I or Type-II connectors that support CAN based communication per

837-411: The stubbornness of the two parties. MVB, Profibus and WorldFIP were proposed as a substation bus in IEC TC 57 , but to avoid parallel solutions, IEC TC 57 decided that none will be used and favored Ethernet as a common denominator. The MVB frames are not compatible with IEC 61158-2 fieldbus frames as it omits most of the preamble synchronization (which is not required if zero-crossing detection

868-467: The vehicle network, as the medium of data exchange. The automotive industry quickly realized the complexity of wiring each module to every other module. Such a wiring design would not only be complex, it would have to be altered depending on which modules were included in the specific vehicle. For example, a car without the anti-lock brake module would have to be wired differently than one that included anti-lock brakes. The industry's answer to this problem

899-415: Was introduced to replace the multitude of field buses in the train equipment. Despite the advantages of the MVB field bus, many vehicle buses are still built from CANopen , WorldFIP (in France ), LonWorks (in the USA ) and Profibus components. While the WorldFIP , CANopen , Lonworks and Profinet are controlled by international manufacturer associations targeting a wide range of application, MVB

930-444: Was tailored to the rolling stock application, with the goal of plug-compatibility, and therefore allows no options. This was intentional as the fight between the field busses raged in the 1990s and the decision of the IEC that any of the eight field busses was a standard did not help plug-compatibility. MVB modules are more expensive than for instance CANopen or LonWorks components. This

961-473: Was to create a central network in the vehicle. Modules could be 'plugged' into the network and would be able to communicate with any other module that was installed on the network. This design was easier to manufacture, easier to maintain and provided the flexibility to add and remove options without affecting the entire vehicle's wiring architecture. Each module, a node on the vehicle network, controls specific components related to its function and communicates with

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