1、 IEEE Standard for Communications Protocol Aboard Passenger Trains Sponsored by the Rail Transportation Standards Committee IEEE 3 Park Avenue New York, NY 10016-5997 USA 4 March 2011 IEEE Vehicular Technology Society IEEE Std 14732010 (Revision of IEEE Std 1473-1999) IEEE Std 1473-2010 (Revision of
2、 IEEE Std 1473-1999) IEEE Standard for Communications Protocol Aboard Passenger Trains Sponsor Rail Transportation Standards Committee of the IEEE Vehicular Technology Society Approved 8 December 2010 IEEE-SA Standards Board Approved 8 August 2011 American National Standards Institute Abstract: Comm
3、unications protocols to be used for inter-unit and intra-unit serial data communications between subsystems aboard passenger trains are defined by this standard. Minimum acceptable parameters for a network that can simultaneously handle monitoring and control traffic from multiple systems are set fo
4、rth. While the network is not vital, it is intended to be capable of carrying vital messages. Keywords: communications networks, communications protocol, commuter rail transit, IEEE 1473, light-rail transit, rail transit, train bus, vehicle bus The Institute of Electrical and Electronics Engineers,
5、Inc. 3 Park Avenue, New York, NY 10016-5997, USA Copyright 2011 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 4 March 2011. Printed in the United States of America. IEEE is a registered trademark in the U.S. Patent +1 978 750 8400. Permission to photoc
6、opy portions of any individual standard for educational classroom use can also be obtained through the Copyright Clearance Center. Copyright 2011 IEEE. All rights reserved. ivIntroduction This introduction is not part of IEEE Std 1473-2010, IEEE Standard for Communications Protocol Aboard Passenger
7、Trains. Rail vehicles are increasingly being built using pre-assembled modules that perform many different functions. More and more, these modules are communicating over serial data communication links for purposes such as traction control, diagnostics, and passenger information. Interoperability an
8、d interchangeability of these modules require adherence to standard communication protocols and common network management procedures. Rail vehicles may be coupled during operation to form trains. Trains typically consist of one or more basic operating units coupled in combinations of varying length.
9、 Train length may be changed frequently to suit service requirements. The serial data communications network is expected to maintain operation without manual intervention when two or more vehicles are coupled or when uncoupling takes place. To this purpose, the network needs sequential numbering, or
10、ientation, and self-identification of vehicles. Rail vehicles may be semi-permanently coupled into groups of vehicles not normally or readily separable during normal operation, i.e., a basic operating unit. In these cases, the network may be preconfigured to care for sequential numbering, orientatio
11、n, and self-identification. The IEEE Rail Transit Vehicle Interface Standards Committee established the Working Group on Communications Protocol Aboard Trains in 1996. It was chartered to specify the protocols for intercar and intra-car serial data communications aboard passenger trains. The working
12、 group has decided to reference three complementary technologies specified by other entities and to define the corresponding profiles for all vehicles and trains: Type L protocol, a general-purpose control networking protocol used for connecting equipment with its sensors and actuators, is defined i
13、n ANSI/CEA-709.1 and ANSI/CEA-709.3. Type T protocol, which addresses the real-time, availability, and integrity requirements of critical on-board train control functions and consists of a train and a vehicle bus, is as defined in IEC 61375-1: 2007. Type E protocol, which refers to the Ethernet tech
14、nologies defined in the IEEE Std 802.3 standards and addresses the needs for scalable architecture and high speed networking suitable for the implementation of modern application and multimedia services. Note that Type L, T and E protocols defined in this standard shall not be confused with other co
15、mmunications protocols that are called LTE (Long Term Evolution) as used in 4G (Fourth Generation) communications standards. These other LTE wireless protocols are defined in international performance and interoperability are not provided by this standard. Inter-unit communication refers to basic op
16、erating units linked through a train network, which is threaded from basic operating unit to basic operating unit, either through jumper cables or through automatic couplers. When train-line interoperability between basic operating units is not required, Type L, Type T or Type E protocol shall be us
17、ed as the train network. When train-line interoperability between basic operating units is required for compliance with the IEC 61375-1: 2007, Type T protocol shall be used as the train network. Table 1 provides the list of permitted protocol combinations. Each combination has specific requirements
18、or limitations, as identified in the following: a) The combination I is required for performance and interoperability in compliance to IEC 61375-1: 2007 and optionally to UIC 556. IEEE Std 1473-2010 IEEE Standard for Communications Protocol Aboard Passenger Trains Copyright 2011 IEEE. All rights res
19、erved. 9b) The combination II provides interoperability in compliance to IEC 61375-1: 2007 with Type T protocol for control and Type L protocol for the monitoring and diagnostic within the unit. c) The performance and interoperability requirements in combinations III and IV must be specified, verifi
20、ed, and validated by the authority having jurisdiction. d) If determinism is required in combination III, a separate Type L channel shall be used for the control applications. e) Where basic operating units are not normally coupled or uncoupled but are permanently or semi-permanently joined, a train
21、 network shall not be required. f) Combinations not addressed in Table 1 must be approved by the authority having jurisdiction. Table 1 Permitted protocol combinations Unit Network Combination Control Monitoring / Diagnostic Multimedia Train Network I Type T Type T Type T II Type T Type L Type T III
22、 Type L Type L Type L IV Type E/L/T Type E/L/T Type E Type E Table 1 lists four types of applications for the unit network. In the train context, control applications have time-critical functions that require a fixed bandwidth and deterministic behavior. Monitoring and Diagnostic applications are ev
23、ent triggered and have a small bandwidth requirement. The multimedia applications have large bandwidth and low latency requirements typical of systems such as CCTV and PIS. 4.4 Environmental conditions Components implementing this standard are subject to the authority having jurisdiction requirement
24、s for operating temperature, fire retardancy, shock and vibration test, and electromagnetic compatibility. 4.5 Safety considerations WARNING When used for safety-critical applications, safety shall be achieved through the system design. The integrity provided by the protocols in this standard may be
25、 insufficient for safety-critical applications IEEE Std 1473-2010 IEEE Standard for Communications Protocol Aboard Passenger Trains Copyright 2011 IEEE. All rights reserved. 105. Type L protocol 5.1 General This clause defines the profile for the Type L protocol and its physical layer specifications
26、. Type L protocol is a general-purpose, open, interoperable control networking protocol used to connect apparatus as specified in 4.3. Type L protocol is defined in ANSI/CEA-709.1 and ANSI/CEA-709.3. NOTEThe protocol provides a seven-layer stack that implements services at each layer of the OSI netw
27、orking reference model, including the physical, media access, data link, network transport, session, presentation, and application layers. A comprehensive set of network management services is built into the protocol to support the above networks, protocol, and interoperability requirements. 5.2 Pro
28、file The Type L protocol provides a 78 kb/s polarity-insensitive, twisted-pair, cable communications channel. It supports local or link power at each node, and free or bus wiring topology as shown in Figure 4. NOTE 1 The protocol supports both peer-to-peer and centrally controlled network configurat
29、ions, depending upon the application requirements. In general, a peer-to-peer system has higher performance and is easier to manage and maintain. Where deterministic operation is required, the centrally controlled configuration can be used. Further information may be found in Echelon B2. NOTE 2 The
30、network management capabilities along with the published interoperability guidelines as shown in B8 can be used for rapid network configuration and maintenance, as well as to provide apparatus interoperability. Figure 4 Type L free and bus topologies 5.3 Physical layer profile The 78 kb/s locally/li
31、nk powered twisted-pair, physical layer options are specified in ANSI/CEA-709.3. Further information on the physical layer may be found in Echelon B3 and B4. There shall be either one terminator (free topology) or two terminators (bus topology) on any given segment of the physical bus. The key chara
32、cteristics of the Type L protocol are summarized in Table 2. IEEE Std 1473-2010 IEEE Standard for Communications Protocol Aboard Passenger Trains Copyright 2011 IEEE. All rights reserved. 11Table 2 Type L Protocol characteristics Characteristics Description Topology Free Bus Maximum segment length 5
33、00 m (16 AWG) 2700 m (16 AWG) Termination Circuit Single circuit of 52.3 Two Circuits of 105 Addressing mode Unicast, Multicast, Broadcast Messaging Services Type Unacknowledged, Acknowledged, Repeated, Authenticated, Request/Response Link layer Protocol CSMA Number of nodes Up to 64 per segment, Da
34、ta rate 78 kbps 5.3.1 Network data bus wiring requirements Type L protocol may use several types of cable. When selecting a cable different than specified in B1, the following cable characteristics shall be used. Resistance unbalance 5% maximum Impedance 100 8 , 64 kHz to 1 MHz Attenuation 2.2 dB/km
35、 (0.67 dB/1000 ft) maximum at 78 kHz Propagation delay 5.6 ns/m (1.70 ns/ft) maximum at 78 kHz Mutual capacitance 55.9 nF/km (17.00 nF/1000 ft) maximum Shield If used, connected to link power source ground through a 470 k (10%) 0.25 W metal-film resistor to prevent static build-up Jacket Where requi
36、red, material shall be specified by the authority having jurisdiction 6. Type T protocol 6.1 General This clause defines the profile for Type T protocol, which addresses the real-time, availability, and integrity requirements of critical on-board train control functions. Type T protocol consists of
37、a WTB and an MVB. Type T protocol is defined in IEC 61375-1: 2007. IEEE Std 1473-2010 IEEE Standard for Communications Protocol Aboard Passenger Trains Copyright 2011 IEEE. All rights reserved. 12Table 3 lists the main characteristics of Type T protocol profiles for a train and for a unit/vehicle co
38、nfiguration. Table 3 Type T protocol characteristics 6.2 Profile 6.2.1 Train bus The WTB defined in Clause 4 of IEC 61375-1: 2007 shall be used as a train bus to connect basic operating units into trains that may change composition during normal operation. The basic operating units may be connected
39、by automatic couplers or by hand. 6.2.2 Vehicle bus The MVB defined in Clause 3 of IEC 61375-1: 2007 shall be used to connect on-board apparatus in train control applications within a basic operating unit. Characteristics WTB: Train Bus MVB: Vehicle Bus Topology Open bus860 m (wire) Closed bus300 m
40、(wire) 2000 m (optical fiber) Media Access Control Master/slave Master/slave Mastership Master selected at startup, backups Rotating master, backups Configuration Variable, reconfigurable at each train com-position change Fixed, factory preconfigured Addressing mode Relative to Master, assigned duri
41、ng inauguration Absolute (physical or logical), assigned by design Node orientation Right/left, front/rear No orientation Number of nodes Up to 32, one or two per vehicle Up to 256 in the same vehicle Medium Twisted shielded pair Optical fiber /Twisted Shielded Pair Connectors 4 9-pin sub-D TSP: 2 9
42、-pin sub-D Optic: ST (BFOC/2.5) Redundancy Line always duplicated Line duplicated by default Data rate 1.0 Mb/s 1.5 Mb/s Response time 100 ms typical 10 ms typical Hamming distance 4 4 (8 on optical fiber) Medium access Cyclic (n 25 ms) and sporadic Cyclic (n 1 ms) and sporadic Link control Source-a
43、ddress broadcast Source-address broadcast Device classes Intelligent node Intelligent and simple devices IEEE Std 1473-2010 IEEE Standard for Communications Protocol Aboard Passenger Trains Copyright 2011 IEEE. All rights reserved. 137. Type E protocol 7.1 General This clause defines the profiles fo
44、r Type E protocol, which specifies the Internet Protocol (IP) communication as per IETF RFC 791, over a 10 / 100 BASE-T Ethernet network based on IEEE Std 802.3. Two Type E profiles are defined. The unit network profile handles the network communication in a basic operating unit and the train networ
45、k profile handles the inter-unit and train level network communication. Type E protocol characteristics are listed in Table 4. Table 4 Type E protocol characteristics 7.2 Unit network profile The unit network profile specifies the characteristics and the requirements for communication of Ethernet ba
46、sed End Station (ES) within a basic operating unit assembled from one or more vehicles, in a fixed configuration, as shown in Figure 5. Figure 5 Unit network architecture with a ring topology The unit network consists in one or more Vehicle Switches (VS), that forward and manage the Ethernet traffic
47、, zero or more Cabling Switches (CS) to provide additional connection points, zero or more Gateways CharacteristicsUnit NetworkTrain NetworkNetwork TopologyStar / ring, full duplex linkStar / Daisy-chain full duplex linkNetworking technologyEthernet 10/100 BASE -TEthernet 10/100 BASE - TNetwork Cabl
48、eCat 5e (IEC 61156 -6)Cat 5e(IEC 61156 -6 )Device Co nnectors4 pins D coded M12 female4 pins D coded M1 2 femaleMax segment Length100 m100 mRedundancy Between vehicle switchesBetween train switchesVSGWESCSType L / T devicesESVSESES ES ES ES ESESVS VSIEEE Std 1473-2010 IEEE Standard for Communication
49、s Protocol Aboard Passenger Trains Copyright 2011 IEEE. All rights reserved. 14(GW) to connect Type T or Type L networks and the End Stations (ES) which are the devices that communicate on the Ethernet network. The unit network shall implement a redundant, 10/100 BASE-T, full duplex link between the vehicle switches. The vehicle switches shall manage the redundancy to maintain the unit network communication in case of a failure of a switch or a link. The cabling switch is an optional component that may be added to provi
