Marconi OMS 1200
Technical Product Description
221 02-ZAP 701 25/1 Rev C 2006-08-04
© Ericsson AB 2006
03PHB00004AAV-CUA
Commercial in confidence
23 (136)
2.3.2
OMS 1260 Shelf and Cards
The basic subrack structure is illustrated in Figure 2-5.
Figure 2-5: Example of a Basic OMS 1260 Subrack
Fan Tray/
Blanking Plate
63x2Mbit/s LTU
Generic LTU
Power LTU
STM-1/4
CoreCard
Aux/Sync/
Ancillary LTU
Generic Trib
2.3.3
Cooling the OMS 1260 Subrack
The OMS 1260 subrack design incorporates two forced-air cooling fan enclosures in
which two, one or no fans may be fitted according to local configuration options and
operating conditions. Any unused fan slots must be covered with EMC blanking plates
supplied in the core SE.
2.4
Power Supply Architecture
The OMS 1200 equipment requires telecommunications industry standard DC power
supplies as defined in EN 300 132-2 and described in the “Safety Guide” handbook. A
variation is applied in that the
rated voltage range
of the OMS 1200 equipment is
extended to -38.4Vdc at the low end, and to -75Vdc at the high end.
Two power input ports are provided, giving 1+1 protection of the power feeds.
Each power feed is connected to a power LTU, which then supplies the power to the
backplane. Both power feeds are distributed through the backplane to the plug-in card
slots that require them. The power is then combined by diodes on each card and fed
to a DC-DC converter that produces the low-voltage rails required by the card. All card
types other than generic tributary cards and 2Mb/s LTU cards use this power
architecture.
