Nortel DMS 100 Series Maintenance Manual page 20

2-4 Maintenance overview
Alarm circuit
following alarm inputs activate:
•
•
•
The alarm circuit provides two light-emitting diodes (LED) as visual
indicators of the FRAMEFAIL and FANFAIL signals. The alarm circuit uses
a connector interface to drive two additional external LEDs.
Maintenance
features like jacks for operating, data and ABS. These features provide for
interoffice communication and data transmission.
The following figure shows the relationship of NTRX41AA circuit card
functional blocks.
Figure 2-1 NTRX41AA functional blocks
ABS
Fuse modules
Cooling unit 1
Cooling unit 2
Inverter
297-8223-550 Standard 04.02 November 2000
The alarm circuit consists of transistor logic that the
battery-input voltage that triggers a FRAMEFAIL signal for an inverter
alarm, talk battery module alarm, or fuse module alarm
battery-return voltage that triggers a FRAMEFAIL signal for a converter
fail alarm
battery-input voltage that generates a FANFAIL signal and triggers an
alarm for the cooling units
The NTRX41AA circuit card provides many maintenance
NTRX41AA
Alarm circuit
Visual
indicators
Maintenance
Breaker
modules
Visual
indicators
Office alarm
Remote alarm
circuit