Embodiments of the present invention are directed to systems and methods for monitoring a status of a plurality of a merchandise display devices for displaying items of merchandise at respective display positions. For example, the method includes monitoring for a change in a preselected characteristic of a circuit defined by an electrical connection between the security devices and a plurality of nodes and between the nodes and an alarm unit. The method also includes determining whether an item of merchandise has been added to or removed from a respective display position based on a change in the preselected characteristic.