Smart sensor line alarm system

A merchandise security system comprising:

• a plurality of security devices, each of the security devices corresponding to a respective display position for an item of merchandise;
• an alarm unit electrically connected to a plurality of nodes, each of the nodes electrically connected to at least one security device,
• wherein the alarm unit is configured to monitor a change in a preselected characteristic of a circuit defined by the electrical connection between the security devices and the nodes and between the nodes and the alarm unit, and
• wherein the alarm unit is configured to determine whether an item of merchandise has been added to or removed from a respective display position based on a change in the preselected characteristic.