According to link distance, it provides different SFP with various input sensitivity. Each input has a bypass relay which is responsible for routing input signal to the output in case of a power failure. The EOD- 3902 features “Change over” and “Recover” capabilities. When the “Change over” is enabled, if one of the input signals is lost, its corresponding outputs are fed by the other input. In this case, when the lost input is retrieved, the signal won’t be connected to its outputs. However, if the “Recover” mode is enabled, the retrieved signal will be automatically switched back to its outputs again. All adjustments and controls can be applied directly by onboard DIP switches and web interface remote control. LED Indicators on the front edge of the card, inform the user about operational status of the module.