Openvox FXS401 Single CH Quad Port FXS Module for A810 A1610 A2410Overview The FXS401 single channel Quad FXS module allows OpenVox Analog A810 A1610 A2410 series cards to terminate four analog telephones per module. Because of the modular design, users can activate additional ports at any time with more modules. The FXS401 module passes all the call features any standard analog telephone line will support. Functions: FXS Foreign Exchange Station FXO Foreign Exchange Office An FXS device initiates and sends ringing