Page460 of 544 NTRB21DTI /PRI/DCHTMDI card
553-3011-100 Standard14.00 January 2002
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Power requirements
The DTI/PRI obtains its power from the backplane, and draws less than
2 amps on +5 V, 50 mA on +12 V, and 50 mA on -12 V.
Foreign and surge voltage protection
Lightning protectors must be installed between an external T-1 carrier facility
and the Option 11C cabinet. For public T-1 facilities, this protection is
provided by the local operating company. In a private T-1 facility
environment (a campus, for example), the NTAK92 protection assembly may
be used.
The NTRB21 circuit card conforms to safety and performance standards for
foreign and surge voltage protection in an internal environment.
Table 1 43
NTRB21 LED states
LED State Definition
DIS On (Red) The NTRB21 circuit card is disabled.
Off The NTRB21 is not in a disabled state.
ACT On (Green) The NTRB21 circuit card is in an active state. No alarm states
exist, the card is not disabled, nor is it in a loopback state.
Off An alarm state or loopback state exists, or the card has been
disabled. See the other faceplate LEDs for more information.
RED On (Red) A red-alarm state has been detected.
Off No red alarm.
YEL On (Yellow) A yellow alarm state has been detected.
Off No yellow alarm.
LBK On (Green) NTRB21 is in loop-back mode.
Off NTRB21 is not in loop-back mode.