Nortel Circuit Card Installation Manual page 535

Card control functions
Control functions are provided by a microcontroller and a Card LAN link on
the digital line card. A sanity timer is provided to automatically reset the card
if the microcontroller stops functioning for any reason.
Microcontroller
The NT8D02 Digital Line card contains a microcontroller that controls the
internal operation of the card and the serial card LAN link to the controller
card. 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 interfaces
— enabling/disabling of individual units or entire card
— programming of loop interface control circuits for administration of
line interface unit operation
— maintenance diagnostics
The microcontroller also controls the front panel LED when the card is
enabled or disabled by instructions from the NT8D01 controller card.
Card LAN interface
Maintenance data is exchanged with the common equipment Call Server over
a dedicated asynchronous serial network called the Card LAN link.
Sanity timer
The NT8D02 Digital Line card also contains a sanity timer that resets the
microcontroller if program control is lost. The microcontroller must service
NT8D02 and NTDK16 Digital Line cards
Circuit Card
Page 535 of 906
Description and Installation