This private exchange 8-port FXO module supports the D-link SPI (Serial Peripheral Interface) internal DVX-8010 bus and is designed to operate with PSTN POTS lines. It supports 100% electronic operation (no relays) based on solid-state DAAs (Data Access Arrangements). The module is electrically isolated, with a capacitive coupled line circuit. Built-in surge protection tested per FCC part 68. Voltages and currents (supplied by the E-main control module): Logic 3.3 VDC @ up to 0.2 Amp. The module includes eight RJ11 ports for line connection. Each port has two LEDs (Light Emitting Diodes). The green LED indicates port status: Solid Green = off-hook, engaged line Blinking green = ringing The red LEDs are used for special indications (on, synchronized, active) when the module is installed in the first (left-most) position in a D-link PBX chassis. Specifications: Environmental Operation Information Temperature: 0-40 degrees Centigrade Humidity: up to 95%, non-condensing Physical Dimensions 90×105 Millimeters Certifications FCC 47CFR part 15 subpart B TBR21 RoHS EC