DS7457i Series Single Zone Input Modules includes the DS7457i and the DS7457iF. Each model has a supervised-input zone for connecting normally-open or normally-closed contacts. The DS7457i Series controls the contacts using 47 kilohm end-of-line resistors. Each model operates with compatible multiplex expansion modules and occupies one multiplex zone address on the system. The DS7457i is designed for intrusion applications while the DS7457iF is designed for fire applications.