US Patent 7617775 Multiple slave logging device

A multiple slave logging device, or “logger” for use in a system such as an electronic blasting system. The logger is able to communicate with multiple slave devices connected to it, and preferably also is able to communicate with a slave device connected individually. The logger preferably utilizes current modulation-based talkback from the slave devices, and optionally may also be adapted to detect the presence of inappropriate slave devices connected to the system.