Abstract: A system and method of communicating via digital radio between a train and a device positioned at the wayside of a railway system, wherein the device detects defects at the wayside and information related to the defects is transmitted from the wayside to the train for display in the locomotive cab. A communications unit having a microprocessor control circuit and a transceiver is electrically coupled, preferably by serial connection, to the defect detector along the wayside. The transceiver of the communications unit is in radio communication with an existing transceiver in the head-of-train (HOT) unit located in the locomotive cab at the head-end of the train. The head-of-train unit has a microprocessor control circuit that drives a display which is preferably alphanumeric, for the purpose of displaying messages related to the defects detected by the defect detector at the wayside, and subsequently transmitted between the transceiver of the communications unit and the transceiver of the HOT unit.

Abstract: Overheated railroad journal bearings, wheels, and other wheel components on a moving or stationary railroad train are detected by amplifying the current signal from an infrared radiation sensor comprising a pytoelectric cell. A reference temperature is sensed by chopping the incident infrared radiation with an asynchronous shutter that momentarilly closes at successive time spacings of shorter duration than the scanning period of the sensor. The amplified signal is converted to a digital signal and processed by a microcontroller and associated hardware and software. The detector automatically and periodically calibrates itself and compensates the temperature signals for any temperature difference between the ambient external temperature and the temperature inside the detector housing. The output signal may be digital or analog.

Abstract: Overheated railroad journal bearings, wheels, and other wheel components on a moving or stationary railroad train are detected by amplifying the current signal from an infrared radiation sensor comprising a pyroelectric cell. A reference temperature is sensed by chopping the incident infrared radiation with an asynchronous shutter that momentarily closes at successive time spacings of shorter duration than the scanning period of the sensor. The amplified signal is converted to a digital signal and processed by a microcontroller and associated hardware and software. The detector automatically and periodically calibrates itself and compensates the temperature signals for any temperature difference between the ambient external temperature and the temperature inside the detector housing. The output signal may be digital or analog.

Abstract: Overheated railroad journal bearings, wheels, and wheel components on a moving or stationary railroad train are detected by amplifying the current signal from an infrared radiation sensor comprising a pyroelectric cell. A reference temperature is sensed by chopping the incident infrared radiation with an asynchronous shutter that momentarily closes at successive time spacings of shorter duration than the scanning period of the sensor. The amplified signal is converted to a digital signal and processed by a microcontroller and associated hardware and software. The software comprises a free-running loop Main Program which is subject to several interrupts. The output signal may be digital or analog and is transmitted to remote signal processing equipment for further processing.