Nortel DMS-100 Series Maintenance Manual page 53

Star Remote System hardware 2-33
U-interface line card (NTBX27AA)
The NTBX27 line cards are located behind the IDC in 3 rows of up to 10 line
cards in each row. A fourth row of slots at the top is empty. The three rows
are arranged into two groups, each containing 15 slots, but supporting up to 14
line cards to form the LSGs. The left group forms the even-numbered LSG and
the right group forms the odd-numbered LSG. Unit 0 of the control shelf
controls the even LSG and unit 1 controls the odd LSGs.
Both the LSGs and the individual line cards in the LSGs are numbered. LSG
numbers in a Star Hub range from LSG-00 through LSG-35. ILD-R line card
numbers range from 00 through 13. Using these numbers, the line cards are
uniquely identified and inventoried in the DMS switch central control (CC) by
their line equipment numbers (LEN), as shown in the table titled "Parts of LEN
for a Star Hub" presented earlier in this chapter.
Point-of-use power supply (NTBX71AA)
The ISDN point-of-use power supply (PUPS) is a dual slot card in the ILD-R
drawer. The PUPS provides +5 V power to the ILD-R line cards in the line
drawer. The NTBX71 samples the output voltage and checks for an over
voltage condition. If an over voltage condition is detected, the PUPS sends
back a signal to the pulse width modulator to power down the NTBX71AA.
To reset the card, the power supply must be removed and installed again.
See the following figure for a functional block diagram of the Star Hub with
ILD-R. All the components of this figure are described in this chapter.
DMS-100 Family NA100 Star Remote System XPM15 and up