516 NT8D02 and NTDK16 Digital Line cardsEach digital telephone line terminates on the NT8D02 Digital Line Cardat a TCM loop interface circuit. The circuit provides transformer couplingand foreign voltage protection between the TCM loop and the digital lineinterface circuit. It also provides battery voltage for the digital telephone.To prevent undesirable side effects from occurring when the TCM loopinterface cannot provide the proper signals on the digital phone line, thecard microcontroller can remove the ±15 V dc power supply from theTCM loop interfaces. This happens when either the microcontroller gets acommand from the NT8D01 controller card to shut down the channel, orthe digital line card detects a loss of the 1 KHz frame synchronizationsignal. The ±15 V dc power supply signal is removed from all 16 TCM loopinterface units at the same time.Each TCM loop interface circuit can service loops up to 3500 ft. in lengthwhen using 24-gauge wire. They support a maximum ac signal loss of 15.5dB at 256 KHz and a maximum dc loop resistance of 210 ohms.Card control functionsControl functions are provided by a microcontroller and a Card LAN link onthe digital line card. A sanity timer is provided to automatically reset the cardif the microcontroller stops functioning for any reason.Control functions are provided by a microcontroller and a Card LAN link onthe digital line card. A sanity timer is provided to automatically reset the cardif the microcontroller stops functioning for any reason.Control functions are provided by a microcontroller and a Card LAN link onthe digital line card. A sanity timer is provided to automatically reset the cardif the microcontroller stops functioning for any reason.MicrocontrollerThe NT8D02 Digital Line card contains a microcontroller that controls theinternal operation of the card and the serial card LAN link to the controllercard. The microcontroller controls the following:• reporting to the Call Server through the card LAN link:— card identification (card type, vintage, and serial number)— firmware version— self-test status— programmed configuration status• receipt and implementation of card configuration:— programming of the digital line interfacesNortel Communication Server 1000Circuit Card ReferenceNN43001-311 01.04 StandardRelease 5.0 23 May 2008Copyright © 2003-2008, Nortel Networks.
