Nortel DMS-100 Series General Description Manual page 80

3-12 Ringing in Series II peripherals
Also on each shelf is a control complex made up of a power converter,
processor, and digroup control card; the term unit is used to describe this
control complex. When both units are in-service, unit 0 supports the
even-numbered logical drawers in the LCM. Unit 1 supports the
odd-numbered logical drawers.
The LCM ringing operation is provided by two ringing generators, RG 0 and
RG 1, located at the top of the LCE frame shown in Figure 3-4, "LCE frame"
on page 3-13. The ringing generators provide ringing to both LCMs in an LCE
frame. Under normal operations, the frequency generator circuit in RG 0
supplies ringing frequency to the even-numbered LCM in the frame (LCM 00
in Figure 3-4, "LCE frame."). Similarly, RG 1 supplies ringing frequency to
the odd-numbered LCM (LCM 01 in Figure 3-4, "LCE frame."). The LCM is
also capable of switching ringing generators. A single ringing generator can
supply ringing frequency to all line drawers in the LCE frame.
The ringing generator also contains an ANI/coin circuit that provides four
voltages for ANI/coin operations. The ANI/coin circuit in RG 0 serves unit 0
of both LCMs. The ANI/coin circuit in RG 1 serves unit 1 of both LCMs. If a
failure occurs in either one of the ANI/coin circuits, both LCMs are switched
to the takeover mode of operation. In takeover mode, the remaining ANI/coin
circuit is capable of serving both LCMs in the frame.
Ringing input is fused at the RA and RB fuses located in the baffles above each
LCM shelf (see Figure 3-4, "LCE frame.""). Each fuse controls all the even-
or odd-numbered logical drawers in an LCM shelf. The following table
identifies the fuse associated with each grouping of even or odd logical
drawers.
Table 3-9 RA and RB fuse connections
Logical drawer grouping
Even drawers
Odd drawers
297-1001-131 Standard 06.01 October 2000
LCM 0 LCM 0
Shelf 04 Shelf 21
RA RB
RB RA
LCM 1 LCM 1
Shelf 38 Shelf 55
RA RB
RB RA