Method and apparatus for remote control of a locomotive throttle controller
First Claim
1. A method for controlling a locomotive from a remote host first computer, said locomotive having a throttle controller equipped with a second computer, said method comprising the steps of:
- (a) establishing two-way transmission of signals representing digital data packets between said first computer and said second computer;
(b) transmitting signals representing digital data packets representing engine control commands from said first computer to said second computer at time intervals no greater than a predetermined maximum time interval, each of said data packets including the following bytes disposed sequentially in time,(I) two bytes of data which serve as a start flag for said data packet,(II) one byte of data, which is reserved as an address for said data packet,(III) one byte of data, which is reserved to indicate different types of packet,(IV) two bytes of data, a first header byte representing the type of information represented by said data packet and a second header byte representing a version number, used to facilitate implementation with successive software versions,(V) at least one byte of information,(VI) at least two bytes representing integers calculated for a cyclic redundancy check, and(VII) two bytes which serve as an end flag for said data packet,wherein ambiguity between said at least one information byte in Step (V) and said end flag bytes of Step (VII) is eliminated by the following substeps,(A) using known numeric values for said end flag bytes,(B) selecting a first byte of said end flag bytes, and, whenever the numeric value of said first byte appears in the stream of bytes to be transmitted, transmitting its numeric value twice in sequence, and(C) in said second computer, interpreting said twice transmitted numeric value as a single byte of information, and not as an end flag;
(c) driving signals on trainlines via said throttle controller means based on said engine control commands; and
(d) responding to one of corruption of transmission and loss of transmission from said first computer.
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Accused Products
Abstract
A protocol is provided for bi-directional communication of control signals between a host unit and a slave unit. The protocol is particularly adapted to the control of a locomotive from a remote host computer.
The protocol provides for transmission of digital signals indicative of control commands from the host computer to the slave computer, and simultaneous transmission of digital signals indicative of diagnostic information from the slave computer to the host computer.
Information is transmitted in the form of data packets, and means are provided, in the receiving computer, for detecting corruption of transmission, or loss of transmission, and for providing a safe response to either of such conditions.
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Citations
24 Claims
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1. A method for controlling a locomotive from a remote host first computer, said locomotive having a throttle controller equipped with a second computer, said method comprising the steps of:
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(a) establishing two-way transmission of signals representing digital data packets between said first computer and said second computer; (b) transmitting signals representing digital data packets representing engine control commands from said first computer to said second computer at time intervals no greater than a predetermined maximum time interval, each of said data packets including the following bytes disposed sequentially in time, (I) two bytes of data which serve as a start flag for said data packet, (II) one byte of data, which is reserved as an address for said data packet, (III) one byte of data, which is reserved to indicate different types of packet, (IV) two bytes of data, a first header byte representing the type of information represented by said data packet and a second header byte representing a version number, used to facilitate implementation with successive software versions, (V) at least one byte of information, (VI) at least two bytes representing integers calculated for a cyclic redundancy check, and (VII) two bytes which serve as an end flag for said data packet, wherein ambiguity between said at least one information byte in Step (V) and said end flag bytes of Step (VII) is eliminated by the following substeps, (A) using known numeric values for said end flag bytes, (B) selecting a first byte of said end flag bytes, and, whenever the numeric value of said first byte appears in the stream of bytes to be transmitted, transmitting its numeric value twice in sequence, and (C) in said second computer, interpreting said twice transmitted numeric value as a single byte of information, and not as an end flag; (c) driving signals on trainlines via said throttle controller means based on said engine control commands; and (d) responding to one of corruption of transmission and loss of transmission from said first computer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An apparatus for controlling a locomotive from a remote host first computer, said apparatus comprises:
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(a) a throttle controller for driving signals on trainlines in said locomotive, said throttle controller having a second computer; (b) said remote host first computer through which said locomotive is controlled via said second computer; (c) means disposed in said first computer for receiving signals indicative of engine control commands, and for representing these commands as signals formed as digital data packets; (d) means for two-way transmission of signals formed as digital data packets between said first computer and said second computer at time intervals no greater than a known maximum time interval, said means for two-way transmission including a means for transmitting sequentially in time for each of said data packets, (I) signals representing two bytes of data which serve as a start flag for said data packet, (II) signals representing one byte of data, which is reserved as an address for said data packet, (III) signals representing one byte of data, which is reserved to indicate different types of packet, (IV) signals representing two bytes of data, a first header byte representing the type of information represented by said data packet and a second header byte representing a version number, used to facilitate implementation with successive software version, (V) signals representing at least one byte of information, (VI) signals representing integers in form of two bytes calculated for a cyclic redundancy check, and (VII) signals representing two bytes which serve as an end flag for said data packet, wherein ambiguity between signals representing said at least one information byte Item (V) and signals representing said end flag bytes of Item (VII) is resolved by the following subitems, (A) means for defining known numeric values for said two end flag bytes, (B) means for selecting a first byte of said two end flag bytes, and, whenever the numeric value of said first byte appears in the stream of bytes to be transmitted, transmitting signals representing its numeric value twice in sequence, and (C) means disposed in said second computer for interpreting said signals transmitted twice in sequence as a single byte of information, and not as an end flag; (e) means disposed in said second computer for receiving said signals formed as digital data packets, and for generating signals for driving the trainlines of said locomotive; and (f) means disposed in said second computer for responding to one of corruption of transmission and loss of transmission from said first computer. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification