The American Fibertek 82SL multiplexes 16 channels of dry latching contact closure on one singlemode fiber. A user selectable feature allows the contact status to be maintained unchanged or reset through power-cycle and loss-of optical-power. A reset button is available to clear all contact status to the default state. Individual channel LEDs on the transmitter and the receiver units indicate the channel status. These systems require no field adjustments at installation or additional maintenance thereafter. Diagnostic indicators provide a quick visual indication of system status.