"Multiple-try" discriminators could be reset remotely. A single-try strong link might have an event sequence of 24 events, whereas a multiple-try device would have more: the MC2969 had 47..
Remote resetting was feasible for "multiple-try" discriminators. Single-event strong links usually contained an event sequence of 24, whereas multiple-try devices might have extended sequences; the MC2969 demonstrated this with a sequence of 47 events.