US Patent 6966262 Current modulation-based communication from slave device

Current modulation-based talkback in a system in which the background noise in the level of current draw is minimized such that the talkback is effected with a desirably high signal-to-noise ratio, such as by the master device holding the system voltage low such that the slave devices will not be performing tasks that would cause the current draw on the system to have an undesirable level of background noise, or, in an electronic blasting system, by preventing all other detonators from performing tasks that would create an undesirable background current draw when a particular detonator is talking back.