Keypad with audit trail for high density mobile systems

A control device for a mobile storage system includes a data entry device, such as a numeric keypad. The user enters an access code on the keypad, and the access code is compared against a data table including a list of security levels associated with access codes. If the access code entered is included in the data table, the user is permitted to control the mobile storage system according to the access rights granted by the security level associated with the access code. Each of the access codes and attempted commands entered in the numeric keypad are recorded in an activity log. The activity log is downloadable to a computer for later review.