US 4,619,425 AGranted

Pulse code system for railroad track circuits

AssigneeAmerican Standard Inc.

InventorHarry C. Nagel

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Abstract

An alternating current code, alternately transmitted in each direction through the rails of a railroad track section, includes a selected number of pulses of alternately positive and negative polarity similar to a bi-polar DC code. Data is transmitted by pulse length, with long and short pulses representing binary digits 1 and 0, respectively. The code pattern, polarity and pulse length, is balanced to eliminate code distortion by track energy storage. The code pattern transmitted is determined, and received pulses are decoded, by a microprocessor with associated memory (PROM) which processes local input and output data. The processor also checks the operation of the associated apparatus, including input and output circuit and hardware integrity through monitor devices and feedback signals. A unique check signal output is produced only when the various monitor networks determine all operation is proper and that the various elements are free of faults. The generation of operating energy for the associated apparatus by a power supply unit is dependent upon its continued reception of this check signal from the processor. Absence of the check signal indicating apparatus fault or operational failure shuts down the system operation at that location.

Claims14

Dependent claims

A pulse code system for transmitting in each direction through the rails of a section of railroad track data representing wayside conditions and controls associated with that section, comprising,

(a) transmitter/receiver means coupled to the rails at each end of said section for transmitting and receiving through said rails an alternating current code having selected pulse characteristics,
(b) a data processor means coupled to each transmitter/receiver means for selecting, in accordance with applied input data, the pulse characteristics of each code transmitted through the rails to the receiver at the other end of said section and for decoding the data carried by the code pulses received through the rails from the transmitter at said other end,
(c) an input network coupled to each processor means for supplying wayside input data for transmission to said other end,
(d) an output means coupled to each data processor means for outputting the data decoded from received code pulses,
(e) a power supply means coupled to each output means for providing operating energy,
(f) a first monitor network controlled by each data processor means and coupled for dynamically checking the operation of the associated output means and responsive for supplying monitor signals to said processor means when correct operation of the associated output means and said first monitor network is detected,
(g) a second monitor network jointly controlled by each data processor means and associated input network and coupled for checking the integrity of the associated input network and completeness of the input data supplied,
(h) each data processor means responsive to monitor signals from the associated first monitor network and to the integrity check of the associated second monitor network for generating a check signal, and
(i) each power supply means coupled to the associated processor means for receiving said check signal and enabled for providing operating energy to the associated output means only when said check signal is present.

6 more elements

In a pulse code data transmission system for a stretch of railroad track, at each location common to adjacent insulated track sections into which said stretch is divided, the combination comprising,

(a) a pair of transmitter/receiver means, one coupled to the rails of each section for transmitting or receiving a selected pulse code through the rails between that location and the other end of the corresponding section,
(b) processor means coupled to both transmitter/receiver means for selecting the codes to be transmitted through the rails in accordance with input data applied for each section and for decoding the data included in the codes received from the other end of each section,
(c) an input network for each section coupled to said processor means for applying input data designating condition and controls in the corresponding section,
(d) an output means coupled to said processor means for separately outputting the decoded data received by each receiver means,
(e) a power supply means coupled for normally providing operating energy for said output means,
(f) a first monitor network controlled by said processor means and coupled for dynamically checking the operation of said output means by comparing the output data with the corresponding received code,
(g) a second monitor network controlled by said processor means and coupled for checking the integrity of each input network to assure transmission of correct input data for each section,
(h) said processor means responsive to the operation of said first and second monitor networks for generating a check signal only when the operation of said output means checks proper without fault and the integrity of both input networks is assured, and
(i) said power supply means is further controlled by said processor means and is responsive for providing operating energy to said output means only when said check signal is generated.

6 more elements

Dependencies are inferred from the claim text.