A need exists for a controller that senses and controls locking engagement between a locking mechanism having a female member and a male member when a portion of the locking mechanism is attached to a device, particularly a safety device where locking engagement must be tightly controlled to avoid safety hazards. Such a control system is particularly useful in the determination of when a portion of a locking mechanism that is attached to a human worker may safely be detached and safely held, or “docked,” until safety conditions allow for reengagement.