Page 204 of 290
NT8D02 Digital Line Card
553-3001-105
Standard 5.00
June 1999
To prevent undesirable side effects from occurring when the TCM loop
interface cannot provide the proper signals on the digital phone line, the card
microcontroller can remove the ±15 V dc power supply from the TCM loop
interfaces. This happens when either the microcontroller gets a command
from the NT8D01 controller card to shut down the channel or the digital line
card detects a loss of the 1 KHz frame synchronization signal. The ±15 V dc
power supply signal is removed from all 16 TCM loop interface units at the
same time.
Each TCM loop interface circuit can service loops up to 3500 ft. in length
when using 24-gauge wire. They allow for a maximum AC signal loss of
15.5 dB at 256 KHz and a maximum DC loop resistance of 210 ohms.
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 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 CE CPU via 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
Summary of Contents for NT1R20
Page 2: ......
Page 4: ...iv 553 3001 105 Standard 5 00 June 1999 iv ...
Page 12: ...xii Contents 553 3001 105 Standard 5 00 June 1999 ...
Page 76: ...Page 52 of 290 Description 553 3001 105 Standard 5 00 June 1999 ...
Page 154: ...Page 130 of 290 NT5D11 Line side T1 Interface Card 553 3001 105 Standard 5 00 June 1999 ...
Page 276: ...Page 252 of 290 QPC452 Basic 500 2500 Analog Line Card 553 3001 105 Standard 5 00 June 1999 ...
Page 306: ...Page 282 of 290 List of terms 553 3001 105 Standard 5 00 June 1999 ...
Page 314: ...Page 290 of 290 553 3001 105 Standard 5 00 June 1999 ...
Page 315: ......