The alarm could be transmitted by a variety of methods, including a distribution SCADA system, a substation wide area network, or a simple auto-dialer alarm system. While some utilities have SCADA covering all distribution breakers, some have no permanent communications to any distribution substation. The extent of any existing alarm type communication, and the cost and feasibility of adding communications where none exists, will have a significant bearing on the decision to apply a HIF detector to trip or to alarm.