Page 160 of 906 NT1R20 Off-Premise Station Analog Line card553-3001-211 Standard 3.00 August 2005Functional descriptionThis functional description of the NT1R20 Off-Premise Station (OPS) analogline card is divided into two parts. First, a description of the card’s control,signaling, and power interfaces is given, followed by a description of how thecard itself functions. See Figure 22.Figure 22OPS analog line card – block diagramInput/outputinterfacecontrolCodecPCMMicro-controllerDS-30Xinterface5.12 MHzclockTx PCMAsync cardLAN linkFrontpanelLEDCard LANinterfaceTipLine interface units 0–3RingCodecPCM Analoghybrid XFMRSignaling relays(ringing, batteryreversal)Line interface units 4–7Line interface unit powerRx PCM1 kHzframe syncControllercardLinesignalinginterfaceControllogicRegSignalingand statusAddress/data bus553-6193Powersupplies+5 V dcanaloghybrid±15 V dcanalogpower+8.5 V dc +5 V dc logic powerRinging– 48 V dcbatteryRsyncAnalogtelephonelinesTipRingAnalogtelephonelinesLoop current/dialpulse detectAnaloghybrid XFMRSignaling relays(ringing, batteryreversal)Loop current/dialpulse detectCard slotaddressBackplane
