A logger for safe logging of electronic detonator data, comprising: an electrical interface (104, 105) allowing electrical connection of an electronic detonator to the logger to send and receive electrical signals to and from an electronic detonator, but incapable of providing sufficient energy to fire the electronic detonator; a user interface (106, 110); an electronic memory operative to store a plurality of unique detonator serial ID numbers and corresponding delay values; and at least one processor operatively coupled with the electrical interface (104, 105), the user interface (106, 110), and the electronic memory; characterised in that the at least one processor is programmed to operate the logger in an automatic logging mode in which the logger: (i) transmits one or more read request messages via the electrical interface (104, 105) without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110), (ii) awaits responsive messaging from a single connected electronic detonator without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110), and (iii) upon receiving responsive messaging from only a single connected electronic detonator: obtains electronic detonator data including at least one of a serial ID number, a programmed detonator ID, and/or a delay value from the responsive messaging without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110), and stores the electronic detonator data in the electronic memory without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110), and thereafter (iv) repeats (i), (ii) and (iii) for a subsequently singly connected electronic detonator without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110); wherein the at least one processor is programmed to provide an indication to the user via the user interface that the connected electronic detonator has been logged during operation in the automatic logging mode without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110). an electrical interface (104, 105) allowing electrical connection of an electronic detonator to the logger to send and receive electrical signals to and from an electronic detonator, but incapable of providing sufficient energy to fire the electronic detonator; a user interface (106, 110); an electronic memory operative to store a plurality of unique detonator serial ID numbers and corresponding delay values; and at least one processor operatively coupled with the electrical interface (104, 105), the user interface (106, 110), and the electronic memory; (i) transmits one or more read request messages via the electrical interface (104, 105) without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110), (ii) awaits responsive messaging from a single connected electronic detonator without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110), and (iii) upon receiving responsive messaging from only a single connected electronic detonator: obtains electronic detonator data including at least one of a serial ID number, a programmed detonator ID, and/or a delay value from the responsive messaging without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110), and stores the electronic detonator data in the electronic memory without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110), and thereafter obtains electronic detonator data including at least one of a serial ID number, a programmed detonator ID, and/or a delay value from the responsive messaging without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110), and stores the electronic detonator data in the electronic memory without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110), and thereafter (iv) repeats (i), (ii) and (iii) for a subsequently singly connected electronic detonator without transmitting any programming messaging to the connected electronic detonator and without requiring user interaction with the user interface (106, 110);