Features Specifications:Fast Optical Modem  Product Features:  E1 G.703 Interface  E1 Signal Jitter/Wander Attenuation   E1 AMI/HDB3 Codes  Local Loopback and Remote Loopback   Automatic Alarm Signaling on both Line and Fiber   18 dB Typical Optical Link Margin  Multiple Link status Indicators Product Description:  The FHC-4030 is designed to provide fiber connection for E1 equipment. It includes a E1 Line Interface Unit that provides E1 line driver/receiver, data/clock recovery, jitter attenuation, AMI/B8ZS/HDB3 encoding, AIS (Alarm Indication Signal) detection, BPV (Bi-Polar Violation) detection, and loop back mode. It offers two modes of Loopback for testing the connection integrity. In the Local Loopback mode, the modem loops back the received E1signal. In the Remote Loopback mode, the modem sends loopback codes to cause the far-end modem to loop back the received optical data. Product Specifications:   Electrical InterfaceE1 G.703 Interface Data Rate 2.048 Mbps +/- 50 ppm Impedance75 Ohm balanced 120 Ohm balanced ConnectorBNC-female, unbalanced DB-15 female, balanced Line CodeAMI/B8ZS Optical Wave Length 802 nm/1300 nm multimode 1300 nm single mode Link Margin 18dBm (min.) multimode @ 62.5mm 15dBm (min.) single mode @ 9mm ConnectorST/FC Configurations: The VLM-100 includes a dipswitch that provides the following configuration selections: DSX-1 Cable Length 5 different impedance selections to match DSX-1 cable at length from 0 to 655 feet E1 Line Coding FormatAMI/HDB3 for VLM-100E1Local Loop BackEnabling Local Loopback ModeRemote Loop BackEnabling Remote Loopback ModeT1/E1 Line AISEnabling the alarm signal to E1 lineFiber Link AISEnabling the Alarm Signal to the Fiber Physical Dimensions-8.9(L)in x 6.5(W)in x 1.6(H)in Weight-1 lb System Power Supply -9 to 12 VDC @ 300 mA Humidity-5% to 95% non-condensing Temperature  Range -0 to 60 - Operating -10 to 85 - Storage Order Info :  FHC-4030G: E1 Fiber Optic Modem