Detonator roll call

摘要

A detonator roll call method wherein each detonator is assigned a unique identifier and, at each detonator, in response to an enquiry signal to all the detonators a count is incremented and compared to the roll call identifier and, if the comparison is positive, a reply is sent by the detonator.

主权项

1. A method of conducting a roll call of a plurality of detonators (12) which includes the steps of:
1. providing a respective roll call counter (36) for each detonator (12); 2. assigning to each detonator a respective roll call identifier (34) which is unique to the detonator (12); 3. generating a command which contains a start signal (44), and at least one parameter, which specifies a detonator status; 4. transmitting the command (44) to all of the detonators (12); 5. at each detonator (12), in response to reception of the start signal (44), setting the respective roll call counter (36) to a respective first specific value (49); 6. polling the detonators (12) by transmitting an enquiry signal (50), by reversal of a voltage applied or transmitted to the detonators (12), to all the detonators; and 7. at each detonator (12): a) in response to reception of the enquiry signal (50), changing the respective first specific value (49) in the roll call counter (36) to a respective second specific value (54); b) comparing (58) the respective second specific value (54) to the respective roll call identifier (34) for the detonator (12); and c) if, at least, the comparison in step b) is positive, and if said detonator status prevails at the detonator (12), causing the detonator to transmit a respective reply signal.