Method of communication
AssigneeDetnet South Africa (Pty) Ltd
InventorIan William Guest
Life of this patent
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Abstract
A method of communicating in a blast system which includes the steps of transmitting timing signals from a master transceiver to a plurality of local transceivers, in response, at each local transceiver, defining a succession of micro-slots and calculating a size of a respective bin which is associated with each micro-slot, transmitting a packet from the master transceiver, at each local transceiver calculating a uniform random value, identifying the bin in which the uniform random value is located and during the micro-slot which is associated with the identified bin, if no transmission of a reply signal from any other local transceiver is detected, in response to the packet transmitting a reply signal from the local transceiver to the master transceiver.
Claims7
A method of communicating in a blast system (10) which includes a blast site (12), a blast controller (22), a master transceiver (24) which is operable under the control of the blast controller (22), and a plurality of detonator assemblies (20) which are respectively deployed at the blast site (12), each detonator assembly (20) respectively including a processor (36), a unique identifier (38) which is stored in memory associated with the processor (36), and a local transceiver (34) which is operable under the control of the processor (36), wherein the method comprises the steps of:
- (a) transmitting timing signals (50) from the master transceiver (24) to the local transceivers (34) thereby to define a succession of frames (52) each of a known time duration (T2−T1) and to synchronise operation of the local transceivers (34) of the plurality of detonator assemblies (20) with the operation of the master transceiver (24),
- (b) dividing each frame (52) into a plurality of slots (56) each of which has a respective predetermined duration (TS), each slot (56) including a respective plurality of micro-slots each of which has a respective defined duration,
- (c) for each slot assigning a respective value (T) to each of a number of micro-slots (66) selected from said plurality of micro-slots in the slot,
- (d) calculating a size (BS) of a bin (B) which is respectively associated with each selected micro-slot (66), wherein the bin size (BS) is dependent on the value (T) assigned to said selected micro-slot,
- (e) transmitting a packet (74) from the master transceiver (24) to one or more local transceivers (34), wherein said packet (74) includes data, information or commands which are linked to at least one local transceiver (34) whereby said local transceiver (34) is prompted to send a respective reply signal (90) to the master transceiver (24), the reply signal (90) including the unique identifier (38) of the respective detonator assembly (20), and
- at said local transceiver (34),
- (f) using a uniform random number generator (78) to calculate a uniform random value (76),
- (g) identifying a bin (B) in which said uniform random value (76) is located,
- (h) identifying the micro-slot (66) which is associated with said identified bin (B),
- (i) during a defined interval (84) in the duration of said identified micro-slot (66), enabling the respective local transceiver (34) to be operative to detect transmission of a reply signal from any other local transceiver, and
- (j) if the detection in step (i) is negative, transmitting said reply signal (90) responsive to the packet (74) from the respective local transceiver (34) to the master transceiver (24).
Dependencies are inferred from the claim text.