MXPA99011673A - Ecp train line communications for railway freight car brakes - Google Patents

Abstract

Se proporciona un método para la comunicación por cable eléctrico de ferrocarril ECP (Neumático Eléctricamente Controlado) de baja energía, en donde el consumo de energía efectuado por el transceptor ECP a bordo de cada vagón de carga disminuye al mínimo de manera que puede ser energizado en forma indefinida por medio de una batería de locomotora estándar. El método de comunicación de baja energía normalmente incluye mantener el transceptor ECP de cada vagón en un modo de espera hasta que reciba una señal del controlador maestro de locomotora para alertarlo. La orden de alertar para el transceptor ECP puede ser sensible a la longitud del mensaje enviado por el Controlador Maestro. Métodos alternativos o adicionales para identificar un mensaje de alerta proveniente del Controlador Maestro pueden incluir el uso de la intensidad de señal del mensaje y hacer que la orden de alertar sea sensible al estado de energía del cable eléctrico de tren ECP. En elúltimo caso, la detección de cero energía en el cable eléctrico de tren es una señal para que el transceptor ECP se alerte.

Description

COMMUNICATIONS BY ELECTRIC CABLE OF ELECTRICALLY CONTROLLED PNEUMATIC TRAIN FOR RAIL CARGO WAGON BRAKES BACKGROUND OF THE INVENTION This invention relates in general to braking systems for ECP (Electrically Controlled Pneumatic) and, more particularly, to a method for implementing communications by electrical cable of low ECP train. energy with which the energy consumption is reduced to such a level that sufficient energy can be provided by means of a standard locomotive battery to power the ECP equipment indefinitely in each car. The AAR has defined rail industry specifications for Electric Controlled Tire (ECP) braking based on the use of the Echelon Lon Works, PLT-10A transceiver version remaining on the power line, as the means to communicate between wagons and the driving locomotive. The communication specifications, as currently defined, require the Echelon transceiver to be "on" at all times, so that it is ready to receive braking orders from the locomotive, as well as to respond to interrogation requests regarding the status of the vehicle.

P1748 / 99MX routine. The Echelon transceiver has a power demand of approximately 300 mW when in the receive mode and 2.5 W when in the transmit mode. The message lengths for transmissions are normally in the order of 20 ms long. The average car transmission task cycle is in the order of two times per minute (except for the last car on the train, which transmits every second). Therefore, the average energy demand associated with the Echelon transceiver is in the order of 320 mW. The AAR specifications allow an average power budget of 10 W per wagon. To provide this level of energy, it is necessary to supply a nominal 230 VDC train electrical cable, for a train of 160 wagons, with a length of 12,000 feet. This has resulted in the need for a power supply of 74 to 230 VDC DC-DC (Direct Current Volts) in a locomotive as a whole, with an energy capacity of 2,500 W, to provide enough ECP energy for 160 wagons and losses due to cable resistance. An emulation system of the low energy ECP system with an average power requirement budget below 500 mW in mode P1748 / 99MX "emulation" is set forth in the co-pending United States Patent Application Serially Owned Series No., entitled "RAILWAY EMULATION BRAKE ", granted on December 31, 1998, and which is therefore incorporated herein by reference, that system provides the energization of a" fully electric "ECP valve system that utilizes the 74 VDC from the locomotive, while emulates a conventional pneumatic service valve operation The energy budget for that system is based on the use of the Echelon transceiver only to report the alarm and to set the system.It does not allow the total ECP functionality of the electrically activated brake application and Graduated brake release The addition of approximately 320 mW associated with having the Echelon continuously on for full ECP functionality can not be sustained in a sufficiently low power budget to operate at 74 VDC. United States Patent Copendent, Commonly Owned, Serial No., entitled "RAILWAY LOCOMOTIVE ECP TRAINLINE CONTROL "presented as a reference on December 31, 1998. In a type of low-energy ECP train electrical cable system, the Echelon receiver can not be energized all the time, as in a P1748 / 99MX conventional system, since the Echelon receiver consumes too much power. A) Yes, it is necessary to provide a "Master Controller" ("MC" - Master Controller ") in the locomotive, ie the HEU, to tell each load wagon in the train to" turn on "its Echelon receiver so that the Master Controller It can issue orders to the freight cars Also, in a low energy ECP system, since the communications device, ie the Echelon transceiver, normally shuts down, it is necessary to provide that each car periodically reports its status to the MC. even, the failure conditions need to be handled safely, consequently, there is a need for a low energy ECP communication system where the Echelon transceiver is operated on an intermittent basis, as needed to reduce the average energy demand by below 100 mW, which at the same time provides the power supplied by the standard 74 VDC locomotive battery together with the safe handling of fault conditions.

SUMMARY OF THE INVENTION A communication method is provided by low energy ECP train electrical cable where the power consumption by the ECP transceiver on board each rail car, typically the P1748 / 99MX Echelon transceiver is minimized to a level where the system can be reliably and indefinitely energized by a standard locomotive battery, usually 74 VDC. As a result, it is not necessary to always provide a 230 VDC train electrical cable and all associated electrical equipment required to operate a train in an ECP environment. For versatility, ECP cargo wagons can be equipped to operate in dual modes. At the initial start of the train, each ECP cargo wagon can detect the power of the ECP train electrical cable that prevails. If detected from 100 to 230 VDC, the standard ECP protocol of the normal AAR with the high energy limits is implemented. However, if less than 100 VDC is detected, the ECP low energy communication mode of conformity with the invention is implemented. The low energy communication method includes placing the Echelon transceiver in a standby mode during normal operation and activating it when desired. The Locomotive Master Controller can control a device, or circuitry, in each ECP load wagon to put the Echelon transceiver on hold or alert. The control to alert the Echelon transceiver can be instituted by making the alert order sensitive to the length of the message sent by the MC. For example, routine status messages sent by the MC P1748 / 99MX to each car are usually in the order of 20 ms. Therefore, the warning order can be made substantially longer, for example 50 ms. Similarly, a series of shorter messages that occupy the 50 ms time period can also be used to issue the alert order. To return the Echelon to standby after it has been "turned on", the MC can issue a specific command to return the Echelon to wait. Alternatively, if no message is received after a period of time, for example 2 minutes, the device, or circuitry, in the cargo wagon can, automatically, return the Echelon to wait. Additionally, the signal strength of the message sent by the MC can be used to identify the alert order. Another alternative to control the wait / alert status of the Echelon transceiver is also to make the alert order, sensitive to the power status of the ECP train electrical cable. Specifically, the zero energy detection of the electric cable is a signal to activate the Echelon transceiver. The last type of control also provides a degree of protection in circumstances of failure. Other details, objects and advantages of the invention will be apparent from the following detailed description and the accompanying drawings of certain embodiments thereof.

P1748 / 99MX BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the invention can be obtained by considering the following detailed description in conjunction with the accompanying drawings, wherein: Figure 1 is a schematic of a currently preferred configuration of the on-board components of an ECP car; and Figure 2 is a logic diagram of a currently preferred mode of a low energy ECP operation.

DETAILED DESCRIPTION OF CERTAIN MODALITIES Referring now to the figures, there is shown in Figure 1 a presently preferred configuration of the components on board an ECP wagon, including a microcontroller 5 connected to an ECP battery 8. The microcontroller 5 governs a switch of energy 11 for selectively powering a transceiver 14. The microcontroller 5 also controls a power supply 17 for converting energy, which can be supplied by an electric train wire ECP 20, at a desired voltage, from about 30 to 250 VDC, nominal. It should be understood that, while referring to "100 VDC" or "230 VDC", these nominal voltages, and the voltage may vary depending on the P1748 / 99MX apparatus and operating conditions, which include: the transmission distance in trains of variable lengths. It will also be evident that other voltages could be used satisfactorily. The transceiver 14 is connected to the electric cable ECP 20 to send transmissions thereto. The microcontroller 5 also monitors a filter / peak level detector 23 connected to the electric cable ECP 20, which can identify that a transmission is being sent to that particular ECP wagon, and a voltage measuring component 26 (T / L) of electrical cable, also connected to the ECP 20 electrical cable, to monitor the voltage level and allow the microcontroller 5 to determine whether sufficient voltage is available for operation in the standard 230 VDC mode, or in the low power mode. Since the transceiver 14, typically an Echelon transceiver, is by far the largest source of power consumption in the ECP wagons, the main consideration is to control the operation of the transceiver 14 to minimize the average "on-time" of that device. . This includes two basic requirements: (1) supply on board the ECP wagon, controlled by the locomotive or by another wagon on the train, to normally maintain each ECP wagon transceiver in the "standby" mode, but which is capable of " alert him "and turn on the portion P1748 / 99MX receiver, and (2) system protocol design to minimize the average "firing" of the transceiver of each ECP car, while maintaining the same functionality as the AAR ECP specifications. As described in detail below, both work in conjunction with each other in a system according to the invention to minimize energy consumption.

ACTIVATION WAITING CAPACITY The signal on the PLT-10 Echelon electric cable operates on a dispersion spectrum carrier, with frequencies over a band of approximately 125 to 450 KHz. The ECP equipment in each wagon includes a peak / filter level detector 23, which has a bandpass filter and peak level detector portions to provide independent and redundant ways to identify an individual ECP wagon in which it is being conducted. an Echelon transmission. This detected signal can be converted by means of a standard analog-digital converter and interfaced with a microcontroller 5 of very low energy. Alternatively, a gate array device (not shown) can be used in place of the microcontroller 5. Either of these devices could also be used to monitor the brake line pressure, if desired.

P1748 / 99MX If the carrier frequency is detected for a certain period of time, the Echelon receiving portion would be on and ready to receive messages in the normal way. The threshold time for a carrier signal to result in Echelon activation would be in the order of 50 ms. This allows routine status messages, which are in the order of 20 ms long, from each car, to be transmitted without causing all wagons in the train to turn on their Echelon transmitters. The driving locomotive, or any wagon, may choose to turn on all the wagons in the train by sending a long transmission, or a series of sequential transmissions, that exceed the defined threshold (over 50 ms). An additional time, in the order of 100 ms, is required for Echelon systems to turn on and be ready to accept messages after which normal message transmission may be received. The last train car could operate preferably, with the transceiver always on. When the "turn on" message is received, it would replicate with its own long message transmission replica (over 50 ms). In this way, wagons at the end of the train, which would have the lowest threshold level to detect, would be given a second "alert" call with a stronger signal, P1748 / 99MX compared to the signal received from the driving wagon. Another improvement for the design would be to automatically adjust in each wagon, the signal strength that is used to detect the "turn on" command. This can be done by periodically checking the signal strength of short routine messages, 20 ms, compared to the noise level. This adjustment can be software-based, as a function of signal strength after analog-to-digital conversion. Moreover, the same circuit used for the "alert" function can also be used to measure the Echelon signal strength and to establish the order of the car, by AAR specifications. Once the transceivers "on the wagons are turned on, a specific message can be sent to return them to the" standby mode. "If there are no Echelon messages for a certain period of time, nominally 2 minutes, the car systems will automatically return the Echelons. In the standby mode, as shown in Figure 2, each ECP wagon will know which operating protocol to use based on the voltage of the power cable.When powering up, the power of the power cable 20 is detected in block 30. If the voltage is over 100 VDC, in the range of 100 to 230 VDC, the "AAR" protocol P1748 / 99MX Standard "will be implemented in block 33, with the Echelon receiver" turned on "continuously as indicated in block 36. If the power to the power cord is subsequently turned off or drops below 100 VDC, the Normal ECP mode operation can still be maintained using the 8 ECP battery, as indicated in block 39. In the case where, when starting, the electrical cable voltage is below 100 VDC, the "energy saving" protocol ", as described in more detail below, will be implemented as indicated by block 42. In the initial energization of the electric cable, under 100 VDC, the voltage of the electric cable 20 is further verified to determine if it is at least 30 VDC If the voltage is due or 30 VDC, the ECP equipment shuts down, as indicated in block 45. However, if at least 30 VDC is detected, transceiver 14 will be turned off, in block 48, by a period of time, has nominally 2 minutes, waiting for a transmission, whose period of time extends with the transmissions received. The train test and the order of the wagon would be by standard AAR specifications. The wagon order information is retained by each car, and is used to define routine states that report time intervals. Following completion of standard AAR train test procedures and ordering of P1748 / 99MX wagon, the locomotive would send three redundant messages for the "low power" mode of operation, after each wagon put the Echelon 14 transceiver in a standby mode, as indicated in block 51. The locomotive would then start a series of "alert" messages, such as a long message, for example having a length of 750 ms, to alert each transceiver as indicated in block 42. Each wagon would then be interrogated to ensure that the circuitry of Activation is functional. Subsequent to this test, wagons would be returned to standby mode, in block 51 to summarize normal operations. The waiting mode would be imposed by a waiting message or by a "time out", that is, the expiration of the nominal time period of 2 minutes without received transmissions. As in the operation mode above 100 VDC, the voltage of the electric cable 20 is monitored so that if the voltage increases to above 100 VDC, as detected in block 30, the low energy mode can be changed to of standard ECP operation in block 33, with associated higher power limits. In the event that the "alert" function does not work on any of the wagons, the locomotive engineer could choose to disable the energy saving mode and operate with the Echelon all the time. For P1748 / 99MX achieve this, the energy would be cycled to the electric cable 20 and the ECP locomotive system would be ordered not to use the energy saving mode. This would be acceptable for trains of shorter lengths and fewer wagons, such as approximately 10,000 feet and 120 wagons, assuming that the 8 ECP battery of each wagon is fully loaded at the start. In each case, the locomotive ECP system can provide an engineer with the ability to train the train to maintain battery conditions 8 without being in the low power mode. _ _-; - Once in the "low power" mode of operation, the communications strategy currently preferred may be as follows: 1. Routine status messages, approximately 20 ms long, are sent by unconfirmed transmissions from each car, within a defined time interval, based on the order of the wagons. For example, with a maximum train length of 160 wagons, each car would turn on and send its message every 160 seconds, within the first quarter of a second of the allotted time interval of one second, and then return to standby mode. The status confirmation contained would be the same as the ECP specifications of the AAR. The standard specification is based on the sequential query of each P1748 / 99MX wagon by the locomotive head end unit ("HEU"). 2. The last car, or train end unit ("EOT" - end-of-train) would be allowed a higher energy budget to report to the HEU every second, as in the AAR specifications. The EOT would use the third quarter of the time interval of one second, using the first half of the time intervals of one second for the routine car report. These EOT messages would not be confirmed from the locomotive. 3. In the event that braking actions are not required, every hour the locomotive would send a long transmission to activate each car and issue an updated time synchronization message, in block 48 of Figure 2. Wherever there are actions of braking requiring Echelon 14 activation, followed by a close command to return to standby mode, time synchronization would be provided as part of the order message to return to standby. 4. Due to the message content scheme built into the Echelon system, the small message size and the relatively low message sending speed, even if several individual cars were operated outside their assigned time interval, the output speed of the message would still be relatively high.

P1748 / 99MX 5. The locomotive would need to lose 2 status messages before taking an action to activate all the wagons, and specifically to interrogate the missing wagons. If the missing cars still do not respond, they would be declared defective and the train would return to standby mode. 6. The braking actions would be initiated by sending repeated messages to cover the activation time (50 ms nominal) and the ignition time (100 ms additional). The last carriage of the train, or the EOT unit, responds both to the confirmation ignition and to the acknowledgment of the message of the braking order. 7. While the brake cylinder pressure is being loaded, up or down, the Echelon system remains energized. When there are no order changes from the locomotive for two minutes, the locomotive would send a "return to standby" order. 8. Even if the wagons are in the activation mode, any braking orders would operate as if the wagons were in the standby mode, ie, long messages with repetitions. 9. While in activation mode, the routine wagon status report would revert to the standard AAR defined registration scheme, relocating the automatic low energy report at assigned time intervals.

P1748 / 99MX 10. In addition, the distributed power control ("DPC") of remote locomotives could still be carried out by means of the ECP power cable while in the low power mode. The same method of time intervals would be used, with the sending of short messages. The second and fourth quarters of each one second time interval would be reserved for the DPC. The message lengths would be shorter than the 50 ms required to activate the wagons. A low energy ECP electrical cable communication system, as described above, can provide various advantages. For example, the average power usage of the Echelon 14 transceiver (PLT-10A and Neuron chip) when operating continuously, as in the standard AAR protocol, is approximately 320 mW. In comparison, in the described low energy system, which assumes an average of 2 braking actions (apply and release cycles) per hour, the average energy consumption is reduced to below 100 mW. Of this, approximately 50 mW are consumed by the Echelon 14 transceiver and the others approximately 50 mW are used by the signal level detection circuit 23. Generally, in accordance with the invention, such a low-energy system can P1748 / 99MX provide functionally equivalent ECP operation while using a 74 VDC 20 electric cable instead of the 230 VDC power cable as in the AAR specifications. However, this requires that the average energy consumption per car be below 1 W, with a closer to 0.5 W desirable to allow margins for charged batteries, as well as future options for car moni oreo. If the Echelon 14 transceiver needed to be on full time, there would be little or no margin to operate reliably with 160 cars, especially in low temperature conditions where more energy is required to maintain the charge of the 8 ECP battery. In addition, there would be insufficient energy budget to increase other monitoring functions that may be desired. The overall result is that it is unlikely that there would be sufficient energy budget margin to allow the use of energized ECU systems of 74 VDC on a routine basis if the Echelon 14 transceiver had to be energized all the time. There are several advantages to being able to operate ECP trains on electric cable 20 of 74 VDC as compared to electric cable 20 of 230 VDC specified under the AAR standard. Some examples are listed below, but the list is not intended to be exclusive. 1. Elimination of the need to equip P1748 / 99MX power supplies from 74 to 230 VDC in the locomotives. 2. Lower levels of risk to personnel in relation to the coupling and uncoupling of wagon, as well as maintenance. 3. Potential to eliminate the need to equip a separate ECP 20 electric cable in locomotives, thus supporting the ability for ECP trains to operate without any modification to the trailer unit locomotives. This also supports the development of portable locomotive units with a minimum of locomotive wiring. The third point, related to the elimination of a separated train electrical cable for locomotives, is made easier by going to a 74 VDC operation system, but it also requires other devices not specifically covered by this exposure. In this regard, however, the co-pending United States Patent Application Serial No., entitled "Railway Locomotive ECP trainline Control", hereinabove incorporated by reference, discloses an apparatus for interfacing a UM cable of standard locomotive with the electric cable ECP cable so that only the driving locomotive in a multiple locomotive train would need to be equipped with ECP. The ECP order signals from the locomotive of P1748 / 99MX would be transmitted through the locomotives without ECP equipment by means of a locomotive MU cable to the ECP train electrical cable line. This could be achieved, as set forth in the aforementioned incorporated patent application, providing an adapter for interfacing the ECP train electrical cable line and the locomotive MU cable. Preferably, in addition to the protocol described above, the system can also use control over the power of the electric train cable ECP to communicate with the ECP wagons. This can also add a degree of protection safe from failure for the normal operating system protocol. All systems of the ECP train electrical cable type must have a provision that enables the Master Controller ("MC"), usually part of the locomotive HEU, to turn on and off the power of the train ECP 20 electrical cable. This is required because the power must be turned off whenever the wagons are connected or disconnected from the train. The power is turned off both for safety reasons and also to avoid damage to the connectors. In accordance with the invention, the standard hardware that is already in place is used by the MC to send a signal to the ECP system in each car to "turn on" its Echelon receiver.

P1748 / 99MX 14. The ECP system in each car will include an apparatus, or circuit, such as, for example, the voltage measurement component T / L, shown in Figure 2, to detect a "power off" condition of the vehicle. train power cord 20. Whenever the MC wants to "turn on" all Echelon 14 transceivers, the MC will "turn off" the power of the train's power cord 20 for a prescribed minimum amount of time, usually 50 ms, and then return it to light. Since the electronic ECP of the wagon has backup battery power 8, the interruption of 50 ms of power will not be sequential. The fact that the Echelon 14 transceivers "turn on" automatically when a shutdown condition is detected in a train electrical cable 14, as opposed to when the power is turned on again, is neither capricious nor insignificant. It is more by design, as will be described in more detail below. After the transceivers 14 are turned on, the MC is in control and will order the appropriate action which could be a brake command or a shutdown command. In this scheme, each car will periodically report its status to the MC. After the transceiver 14 of each car, normally the Echelon, has been turned on, the MC will consult each car in sequence. The particular sequence is determined by means of the MC. This order of inquiry will tell the wagon to P1748 / 99MX will zero or synchronize its clock and will also tell that particular wagon the number of seconds after which that particular wagon will "turn on" its receiver during a subsequent periodic MC query. After this consultation the wagon will "turn off" its transceiver 14 until the number of seconds ordered by the MC has elapsed, at that moment the wagon will "turn on" its transceiver 14 and wait for the MC query. In a typical train of 160 wagons, this method will result in the transceiver 14 of each wagon being de-energized for approximately one second of every 160 seconds, assuming that the MC interrogates at the speed of one wagon per second, as in the specifications AAR Consequently, there is an energy saving of 1/160, which is a very significant reduction. Also the MC is always in total control. Security considerations against failure are also a vital part of any operation system. The ECP train electrical wire system of the conventional AAR uses periodic interrogation messages (every second) from the MC to the EOT and from the EOT to the MC to verify the integrity of the communications network. If three consecutive messages are lost by any device, the operational device assumes that there is an error and initiates the actions P1748 / 99MX appropriate. Since in the proposed low energy ECP system, the functionality of both the EOT and the MC is not affected, the method described above to verify the integrity of the network can be used even without any degradation. The ECP electrical cable system of the existing AAR also requires that each car monitors the periodic MC messages (once every second) and that each car take appropriate action if three consecutive messages are lost. In the described low energy ECP system, the transceivers 14 for communication of the wagon, are normally turned off, in this way the previous requirement can not be achieved, at least not in the same way as in the conventional ECP system of the AAR. However, in accordance with the invention, certain other safety precautions against failure can be carried out so that each wagon takes appropriate action in possible failure circumstances, such as when MC messages for some reason can not be received by a passenger. wagon. As described in detail below, the following precautionary measures against failure are in general, equivalent in effect, to the precautions against failure intended to be provided by the AAR specification that each car monitors MC messages and takes appropriate action if three messages are lost There are basically three cases of failure that P1748 / 99MX can eliminate the ability of the MC to activate or "turn on" the Echelon of a car: (1) a failure of the train's electric power cable controller; (2) failure of the MC; and (3) a brake condition in one, or brake in more than one. In each case, together with the manner in which each case is handled, they are described below: In the case of a failure of the electric cable power controller, it is assumed that the power driver of the electric cable may fail in the condition of "turn on". Two additional precautions can be used to solve this problem: (1) the power controller of the electric cable can be designed so that its safety mode against failure of the fault is with the disconnection of the electric cable; and (2) the EOT may have the ability to shorten the electrical cable, thus forcing a disconnection condition. These two precautions provide independent and redundant ways of achieving the desired result. In the second case, a failure of the MC, it is assumed that the power of the electric cable could be either connected or disconnected, depending on the nature of the failure of the MC: Two complementary precautions can also be used to handle this problem: (1) the design of the MC and the communication link between the MC and the controller Power cable P1748 / 99MX can be such that failure of the MC will result in the power cord being turned off; and (2) the EOT may have the ability to shorten the electrical cable. As the first case, these precautions also provide independent and redundant ways of achieving the desired result. The latter case, a brake in two, or more, will result in the wagon transceiver 14 being "disconnected". This is so because, by design, the signal to "turn on" the tranceptor 14 of the car is the condition of "disconnecting" the electric cable. In this way, any brake in two, or any other problem of the electric cable 20, for example, either a short circuit of the electric cable 20 or a failure of the connector, will necessarily produce the desired result, mainly that the transceiver 14 will "turn off" " The low energy communication system according to the invention must also operate in a 74 VDC ECP emulation operation mode. The low energy ECP emulation mode is different from the ECP low energy communication operation mode described above, in which, in the ECP emulation mode there are no ECP braking commands. Instead, the braking order is pneumatic and is derived by the car ECP system from the brake line pressure level. In this way, the P1748 / 99MX most of the low energy communication mode described above, is still applicable to a low power ECP emulation mode of 74 VDC, assuming a certain minimum set of hardware. The minimum hardware could be, for example, a 74 VDC power controller and an Echelon node for a MU Box for train electrical cable. This level of functionality would be relatively simple and inexpensive to aggregate, and it would probably be necessary in any way to achieve the desired level of integrity system. With this functionality, the system could operate in a similar way to the regular ECP mode where the brake commands are electrically communicated to each car via the ECP 20 electrical cable. Either the EOT and the MU Box would turn on the MC function and they would be in constant communication (once per second) with each other, thus ensuring the integrity of the network. Each wagon would be interrogated sequentially as described above. This minimum hardware would also allow the implementation of an electrical cable disconnect feature. That is, to provide the operator with the ability to turn off the power of the electric cable 20, for example by means of a button switch to press, either from the EOT or from the MU Box. This may be a necessary feature in any case, while the wagons would still need to be either P1748 / 99MX connected (increased) or disconnected (subtracted) while in ECP emulation mode of 74 VDC. Either the EOT or the MU Box, or both, could provide communications with the operator, that is, with the engineer, via the locomotive EOT LCU. Of course, if the MU Box is to be used for this purpose, the appropriate radio transceiver would have to be added. The main advantage of communications MU to LCU box is that due to the proximity of the MU Box, this would be a very robust communications link, which is a significant benefit in this type of system. By taking the system additionally still towards the full ECP functionality, the full MC functionality could be added together with an additional Echelon node to the MU Box. This would allow the MU Box to communicate with a simple locomotive device that could generalize the braking order. This locomotive device could be part of an EOT locomotive LCU, or it could be a stand-alone device. Alternatively, this functionality could be part of the Electronic Locomotive Brake, as for example, the "EPIC" system. In effect, this would then be, essentially, a complete ECP system. Finally, although they have been described in P1748 / 99MX details certain embodiments of the invention, it will be appreciated by those skilled in the art, that various modifications to those details could be developed in light of the overall teaching of the exhibition. Accordingly, the particular embodiments set forth herein are intended to be illustrative only and not to limit the scope of the invention to which the full scope of the following claims and any and all embodiments thereof must be conferred.

P1748 / 99MX

Claims (32)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property; A communication method for an electrically controlled pneumatic load train (ECP) brake system having an electric train wire line ECP, a locomotive with a head end unit including a master controller, a plurality of ECP load wagons each including a transceiver to communicate with at least one of the master controller and different transceivers to the ECP load wagons by means of the ECP train electrical cable, the method comprising: a. place the transceiver in a standby mode during normal train operations; b. detect messages sent via the ECP power cable; c. periodically alerting at least a portion of the transceiver's receiver to at least receive messages sent via the ECP power cable; d. return the transceiver to standby mode after receiving the messages; and. alert the transceiver in response to the alert order sent by means of the P1748 / 99MX electric cable ECP; and f. return the transceiver to the standby mode after the alert order. The method according to claim 1, wherein periodically alerting in step (c) further comprises alerting a transmitter portion of the transceiver to respond to messages with wagon status messages. The method according to claim 2, further comprising alerting the transceiver in step (e) in response to an alert order issued by the master controller. 4. The method according to claim 1, further comprising maintaining in a "on" state the transceiver of a last in-line wagon of the plurality of ECP load wagons. The method according to claim 4, further comprising alerting the transceiver in step (e) in response to an alert command issued by the transceiver of the last on-line ECP cargo wagon. The method according to claim 1, further comprising returning the transceiver to the standby mode in step (f) in response to a wait command from at least the master controller. The method according to claim 1, wherein returning the transceiver to the standby mode in at least one of steps (d) and (f) further comprises that the transceiver is returned to the standby mode in P1748 / 99MX response to the passage of a certain amount of time during which no message is detected. The method according to claim 1, wherein the routine messages and the wagon status messages each have a first message length in the order of approximately 20 ms long and further comprising: a. determine the length of detected messages; b. keep the transceiver in standby mode in response to messages corresponding to the first length; and c. alert the transceiver in response to messages that have a second length greater than the first length. The method according to claim 8, wherein the second length is in the order of approximately 50 ms. The method according to claim 2, wherein alerting the transceiver in step (e) further comprises: a. determine a message signal strength of the detected messages; b. comparing the intensity of the message signal with a predetermined signal strength that is indicative of an alert order; and c. alert the transceiver in response to the intensity of the message signal corresponding to P1748 / 99MX the default signal strength. The method according to claim 10, wherein the wagon state messages and messages have a second signal strength and further comprises: a. periodically comparing the second signal strength with a noise level in the ECP train electrical cable through which the messages are transmitted; b. determine a signal strength adjustment factor; and c. adjust the predetermined signal strength by means of the signal strength adjustment factor to record the noise level. The method according to claim 1, further comprising: a. detect a voltage that prevails in the ECP electrical cable; and b. alert the transceiver in response to detecting zero voltage on the ECP power cable. The method according to claim 1, wherein periodically alerting in step (c) is implemented at predetermined time intervals initially communicated to the transceiver by means of at least the master controller during a train start-up procedure. The method according to claim 1, further comprising: P1748 / 99MX a. initially, to alert the transceiver in each of the plurality of ECP wagons during a procedure to start the train via an alert command issued by the master controller via the ECP power cable. b. communicating to the transceiver in each of the plurality of ECP wagons, a time slot allocated for periodic transmission of wagon status messages to the master controller; c. periodically transmitting the wagon status message from the transceiver in each of the plurality of ECP wagons to the master controller in the allotted time slot, and d. returning the transceiver in each of the plurality of ECP wagons to the standby mode after each status message is periodically transmitted to the master controller. 15. The method according to claim 14, wherein a last on-line car among the plurality of ECP wagons transmits the wagon status message once per second. 16. The method according to claim 14, wherein the wagon status messages are not recognized by at least the master controller. The method according to claim 14, wherein the assigned time interval is a one second interval based on the order of wagons according to P1748 / 99MX is determined by the master controller that sequentially interrogates each of the plurality of ECP wagons. The method according to claim 17, wherein the allocated time slot is a time interval of one second and the transceiver transmits the wagon state message within a first quarter of a second of the time interval of one second. The method according to claim 14, wherein the load train includes a train end unit and further comprising: a. the train end unit that transmits status messages to the master controller once per second; b. transmit status messages during a third quarter of every second; and c. reserve a first half of the second for wagon status messages transmitted to the master controller. The method according to claim 19, wherein the messages coming from the train end unit are not recognized by the master controller. The method according to claim 3, wherein no alert order is issued by the master controller for a period of one hour, further comprising: a. issue an alert order to the P1748 / 99 X transceiver from the master controller; and b. issue an updated time synchronization message, simultaneously with the alert order. 22. The method according to claim 6, further comprising issuing an updated time synchronization message, simultaneously with the wait command. 23. The method according to claim 2, further comprising that the master controller: a. detect periodic wagon status messages; b. issue the alert order in response to the failure to detect at least two wagon status messages from any of the plurality of ECP wagons; and c. individually interrogate each wagon of the plurality of ECP wagons by which at least two status messages were not detected. The method according to claim 23, further comprising: a. declare the wagon that does not respond, from among the plurality of ECP wagons, as defective; and b. issuing a waiting order to return to the transceiver in each of the plurality of ECP wagons, to the standby mode. P1748 / 99MX 25. The method according to claim 8, further comprising initiating braking in each of the plurality of ECP wagons emitting from at least the master controller, repeated messages exceeding the second length, to alert the transceiver. 26. The method according to claim 25, wherein the second length comprises approximately 50 nominal ms. The method according to claim 250, further comprising issuing the messages repeated for an additional period of time beyond the second length to accommodate a turn-on time of the transceivers. 28. The method according to claim 27, wherein the additional period of time comprises approximately 100 nominal ms. 29. The method according to claim 25, further comprising emitting, from the transceiver in a last on-line wagon from among the plurality of ECP wagons, a braking order recognition message for the master controller. 30. The method according to claim 29, further comprising issuing, from a train end unit, a braking command recognition message for the master controller. The method according to claim 1, further comprising keeping the transceiver in an "on" state during changes in pressure P1748 / 99 X of the brake cylinder in the plurality of ECP wagons. The method according to claim 14, wherein all the transceivers are in an alert mode which further comprises implementing the wagon status report in the standard AAR interrogation scheme defined, instead of the periodic low energy report in intervals of allocated time. P1748 / 99 X