Abstract: The invention relates to a blasting apparatus for activating a plurality of electrical detonators after predetermined time delays. The blasting apparatus includes a plurality of remote electrical delay devices. Each device is linked to a detonator, and is arranged to be serially programmed with a timing signal, which originates from the central control unit and which determines the time delay. A bidirectional signal harness, having ends which terminate at I/O ports in the control unit, serially links the delay devices to the control unit. In the event of a fault of discontinuity occurring in the harness prior to programming of the delay devices, the discontinuity is detected and the direction of programming along the bidirectional harness is reversed so that those delay devices which, due to the break, cannot be programmed in the initial direction, are programmed with timing signals travelling along the signal line in the opposite direction.

Abstract: A communication system comprises a control station and a number of remote stations connected to the control station by a multi-conductor harness. The control station houses a computer and supplies the remote stations with electrical power, as well as communicating bidirectionally with the remote stations, via the harness. At each remote station, a sensor or other functional module is plugged into an interface. Communication circuitry receives data from and sends data to the control station. The remote station includes an identification device for storing a first code allocated to the remote station by the central computer which identifies the relative location of the remote station, as well as a second code generated at the remote station which identifies the function of the sensor or other functional module.

Abstract: The invention relates to a blasting apparatus for activating a plurality of electrical detonators after predetermined time delays. The blasting apparatus includes a plurality of remote electrical delay devices. Each device is linked to a detonator, and is arranged to be serially programmed with a timing signal, which originates from the central control unit and which determines the time delay. A bidirectional signal harness, having ends which terminate at I/O ports in the control unit, serially links the delay devices to the control unit. In the event of a fault of discontinuity occurring in the harness prior to programming of the delay devices, the discontinuity is detected and the direction of programming along the bidirectional harness is reversed so that those delay devices which, due to the break, cannot be programmed in the initial direction, are programmed with timing signals travelling along the signal line in the opposite direction.

Abstract: The invention relates to a blasting apparatus for activating a plurality of electrical detonators after predetermined time delays. The blasting apparatus includes a plurality of remote electrical delay devices. Each device is linked to a detonator, and is arranged to be serially programmed with a timing signal, which originates from the central control unit and which determines the time delay. A bidirectional signal harness, having ends which terminate at I/O ports in the control unit, serially links the delay devices to the control unit. In the event of a fault of discontinuity occurring in the harness prior to programming of the delay devices, the discontinuity is detected and the direction of programming along the bidirectional harness is reversed so that those delay devices which, due to the break, cannot be programmed in the initial direction, are programmed with timing signals travelling along the signal line in the opposite direction.

Abstract: System for the electrical sequential initiation of explosions comprising a series of initiating modules connected to one another and connectable to a power supply, and a corresponding series of electrically actuable initiators. Each initiating module is connected to an initiator and embodies a non-latching switch for actuating the initiator associated with that initiating module. The non-latching switch comprises a solid state electronic device having an emitter, a gate and a collector, and comprises a short circuit between the gate and the emitter for holding the device in an "off" state to a voltage applied to the collector. The device also comprises an open circuit between the gate and the emitter for turning the device "on" to a voltage applied to the collector, while a diode integrated on the device blocks a reverse supply voltage. The non-latching switch of each initiating module save the first in the series is connected to the initiator associated with the preceding initiating module in the series.