California-based Special Devices Inc., a relative newcomer to the mine/quarry blasting sector, says it is developing a product for commercial mining and blasting called the Electronic Detonator Blasting System. The EDBS comprises one to 1,600 programmable electronic detonators, a two-wire parallel bus with serial protocol, a connector for attaching the detonator to the bus, a logger and blasting machine. According to the manufacturer, the system is robust against ESD, RF, EMI, blast transients and mechanical shock, and provides programmable timing delays up to 10,000 ms in 1-ms increments.

The programmable electronic detonator comprises an Electronic Ignition Module, shell, primary and base charges, lead wires and end plug. An ASIC chip is contained within the EIM electronic board along with a firing/energy reserve storage capacitor, additional electronic components, a connection to each leg wire and a connection to the initiator bridge wire, the company reports.

The bus communications consist of a two-parallel-wire bus that is polarity-independent with serial protocol between the EIMs and a blasting machine. The bus protocol contains command, data bytes and CRC (cyclic redundancy check) for error checking. Communications from the blasting box may be in individual mode (particular to each EIM only) or broadcast mode, in which all EIMs receive the same command — usually charging and fire commands. Special Devices Inc.