Recently, some railroads have begun using locomotives from different railroads that have compatible distributed power operating systems but may also have duplicate road numbers. Consequently, it may be possible to have locomotives with duplicate road numbers capable of communicating with each other within a railway fleet. In most cases duplicate road numbered locomotives will not cause problems with distributed power operations due to the built in safeguards. For example, the distributed power system may prevent linking when a duplicate road number is attempted to be entered at either a remote locomotive or a lead locomotive. However, the present inventors have identified certain cases when duplicate road numbers may cause problems during a communications linking procedure. For example, when a lead locomotive attempts to link with a first remote locomotive having the same road number as a second remote locomotive of a train, both remote locomotives may link, but only the first linked remote locomotive will be recognized by the lead locomotive.
In another problematic situation recognized by the inventors, when first and second trains operating within each other's range of communication include respective lead locomotives having the same road numbers, and the first train includes a remote locomotive having the same road number as a remote locomotive of the second train, communication linking may be compromised. If both trains are set up to link, and the first train links first, the lead locomotive of the first train will link to the remote locomotives in both trains because they have the same road number and are both configured to link to the same lead road number. The lead locomotive of the first train may then have control over both remote locomotives of the first train and the second train and may inadvertently operate the remote locomotive in the second train contrary to commands from the lead locomotive of the second train. Furthermore, if the lead locomotive of the second train attempts to link to its remote locomotive, the remote locomotives of both trains may unlink from the lead locomotive of the first train and relink to the lead locomotive of the second train, which may result in a communications lose indication provided to an operator of lead locomotive of the first train. To remedy such situations, the inventors have developed an innovative technique for controlling communications linking among locomotives so that duplicate road number conflicts among the locomotives are limited.
In an exemplary embodiment, a method of controlling communications linking among locomotives may include identifying, during a communications linking procedure among locomotives, at least two of the locomotives having duplicate locomotive identifiers. The method may also include controlling an operation of at least one of the locomotives responsive to the identification of locomotives having duplicate locomotive identifiers.
In an aspect of the invention, one or more processors 24 may be configured for performing the above described method. The steps necessary for accomplishing the method may be embodied in hardware, software and/or firmware in any form that is accessible and executable by processor 24 and may be stored on any medium that is convenient for the particular application. Processor 24 may take any form known in the art, for example an analog or digital microprocessor or computer, and it may be integrated into or combined with one or more controllers used for other functions related to the locomotive operations.
Accordingly, another exemplary communications linking control method may include ensuring, after being linked, that a remote locomotive responds only to its assigned lead locomotive responsive to a re-linking command. The method may include establishing a communications link between the first train lead locomotive 32 and the first train remote locomotive 36 desired to be controlled by the first train lead locomotive 32. The method may then include receiving, at the first train remote locomotive 36, a communications link request from a second train lead locomotive 38 within communications range. The link request may be encoded with a primary identifier of the second train lead locomotive 38, such as a road number that is the same as a primary identifier of the first train lead locomotive 32. The link request may also be encoded with and a secondary identifier of the second train lead locomotive 38, such as a unique processor address code, different than a secondary identifier of the first train lead locomotive 32.
The link request may be intended for the second train remote locomotive 40 assigned to the second train lead locomotive 38, but may be recognized by the first train remote locomotive 36 due to the primary identifier encoded in the request being the same as the first train lead locomotive's primary identifier to which the first train remote 36 is already linked. The method may then include determining, at the first train remote locomotive 36, that the secondary identifier of the second train lead locomotive encoded in the communications link request is different than the secondary identifier of the first train lead locomotive 32 to which it is currently linked. The first train remote locomotive 36 may then ignore the communications link request from the second train lead locomotive 38 because the linking request has been issued from a locomotive different from the second train remote locomotive's assigned lead locomotive 32.
Based on the foregoing specification, the invention may be implemented using computer programming or engineering techniques including computer software, firmware, hardware or any combination or subset thereof, wherein the technical effect is to control communications linking among locomotives having duplicate road numbers. Any such resulting program, having computer-readable code means, may be embodied or provided within one or more computer-readable media, thereby making a computer program product, i.e., an article of manufacture, according to the invention. The computer readable media may be, for instance, a fixed (hard) drive, diskette, optical disk, magnetic tape, semiconductor memory such as read-only memory (ROM), etc., or any transmitting/receiving medium such as the Internet or other communication network or link. The article of manufacture containing the computer code may be made and/or used by executing the code directly from one medium, by copying the code from one medium to another medium, or by transmitting the code over a network.
One skilled in the art of computer science will easily be able to combine the software created as described with appropriate general purpose or special purpose computer hardware, such as a microprocessor, to create a computer system or computer sub-system embodying the method of the invention. An apparatus for making, using or selling the invention may be one or more processing systems including, but not limited to, a central processing unit (CPU), memory, storage devices, communication links and devices, servers, I/O devices, or any sub-components of one or more processing systems, including software, firmware, hardware or any combination or subset thereof, which embody the invention.
While various embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions may be made without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.