NC-AD300E Manual- 6 -Internal structure of the diagram is as fllows:Back interfaceFront indicator partsPower moduleLink strem power(2)(1)((((4))))((((3333))))((((6))))((((5))))((((8))))((((7))))0-3 8-11 16-19 24-274-7 12-15 20-23 28-31moduleAD300E can set up two kinds of modules: FXO and FXS card, each card has four lines. Themaxium of a single device can be set up eghit cards, totally 32 lines.the sequence of FXS\FXOcards are as shown from (1) to (8), and the number 0 to 31 is the sequence of analog lines..2.2 Interface descriptionInterface to the back of the device:TheTheTheThe backbackbackback ofofofof 300E300E300E300E asasasas shownshownshownshown::::Power: 220V AC;PCM interface:provide the corresponding number on-demond, and it can supportE1 and T1 currently.E1 is the ITU-T developed by the European Association of Postal andTelecommunications (CEPT) digital transmission system named after a group of (ie, PCM30)standard, from 32 64kbps way through the words of the PCM time-multiplexed to form, itstransmission rate is 2.048Mbps . Usually 30, then road transport of voice and other userinformation, the other two telephone channels as the system overhead, transmissionMainControlBoard