Nortel NT1R20, Description

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Page 254 of 290 QPC578 Integrated Services Digital Line Card
553-3001-105 Standard 5.00 June 1999
Physical description
The ISDLC circuitry is contained on a 31.75 cm by 25.40 cm (12.5 in. by
10 in.) printed circuit board. The faceplate of the card (see Figure 72) is
equipped with a red light emitting diode (LED) that lights only when the card
is disabled.
The ISDLC is housed in NT8D13 Peripheral Equipment (PE) Modules (up to
10 cards per module) and QSD65 and QSD80 PE shelves. The following
guidelines define the maximum number of ISDLCs allowed for QSD65 and
QSD80 PE shelves:
— One PE shelf houses up to six ISDLCs if the remaining slots are used.
— One PE shelf houses up to eight ISDLCs if the remaining slots are not
used.
— One QPC82 Power Converter supports up to 18 ISDLCs, provided no
other circuit cards require power from this power converter.
— If the QPC82 Power Converter supports other PE cards, the following
formula defines the total number of ISDLCs where D, an integer, is the
maximum number of ISDLCs allowed and X is the number of other
circuit cards (QPC451, for example) associated with the same power
converter:
D = 3/4 (24 – X)
Note: When ISDLCs serve M3000 Touchphones, this restriction does
not apply because M3000 Touchphones receive power locally.