Abstract: A method and apparatus for calculating the travel time of a vehicle as it transits through multiple locations. The method and apparatus includes a device for detecting a radio signal from a vehicle, attaching information to the radio signal, and transmitting a message packet with the signal and attached information to a central server. The central server stores the message packet. The central server compares the information in the message packet against other stored message packets received from multiple locations. When matching information is found, an algorithm is run to compute a vehicle travel time between two locations.

Abstract: A method and apparatus for calculating the travel time of a vehicle as it transits through multiple locations. The method and apparatus includes a device for detecting a radio signal from a vehicle, attaching information to the radio signal, and transmitting a message packet with the signal and attached information to a central server. The central server stores the message packet. The central server compares the information in the message packet against other stored message packets received from multiple locations. When matching information is found, an algorithm is run to compute a vehicle travel time between two locations.

Abstract: A context (112) of a communication received from a user in a vehicle is determined. The context (112) relates to a characteristic associated with the vehicle. An address of the communication is formed based upon the context (112) of the communication received from the user in the vehicle. The communication is transmitted to a recipient using the address.

Abstract: A controller for a relay controls the pull-in time of the armature of the relay by controlling the power applied to the relay coil. To determine the actual pull-in time, the time of closure of the contacts is sensed and the time at which power is applied to the coil is subtracted from it. The actual pull-in time is then compared with a stored value of ideal pull-in time to produce an error signal. The error signal corrects the level of power applied to the relay coil upon the next actuation of the relay, to make the actual pull-in time approximately equal to the ideal pull-in time. In some embodiments to control the level of power on the coil, a Gray-code counter samples a duty-cycle register in a micro-computer and produces a train of pulses that is filtered to provide a DC control signal. The DC control signal controls the duty cycle of a pulse-width-modulated oscillator that rapidly switches (modulates) the power to the relay coil.

Abstract: A membrane keyboard is provided having a first and second plurality of connectors extending therefrom. The first plurality of connectors is attached at one end to a number of switches on the keyboard and at the other end to a processing circuit apart from the keyboard. One end of the second plurality of connectors is also connected to the processing circuit. A third set of connectors is utilized to connect the ends of the second plurality of connectors on the keyboard in a manner to identify the keyboard to the processing circuit.

Abstract: An onboard unit consisting of a tape recorder, and associated data handling components utilized to provide records of vehicular operating information including speed, distance, power level, braking level, traction motor current and other control events. Each quantity is associated with an incremental distance and/or time which is fixed. In the case of a rail guided vehicle, location signals provided by ground mounted markers are also recorded. Summation of incremental distances as determined from each marker provides an exact location. A magnetic tape unit provides both data storage and operations instruction for a microprocessor based system, allowing convenient alteration or variations in unit function without internal modification. Each unit retains a unique non-volatile serial number which is transferred to each tape allowing convenient correlation of recorded tapes to onboard units.

Abstract: A locomotive is fitted with a transmit and a receive coil. Resonant circuits are packaged within a housing that is secured at a preselected point along a railroad track to serve as a position marker. When the locomotive passes the marker, a signal is coupled from the transmit coil in the locomotive to the marker resonant circuit and back to the receiver coil in the locomotive. Discrimination circuitry is connected to the receive coil for ensuring that the received signal has a minimum amplitude and a particular phase relationship with the signal in the transmit coil. Further, the received signal must maintain these amplitude and phase relationships for a preselected count. Upon proper discrimination, a "mark" signal is generated to an event recorder on board the locomotive.