Overview
150-231-175-01, Revision 01
8
September 23, 1998
HLU-231 List 7E
Network Management Control Bus
The HLU-231 List 7E provides a Network Management Control Bus on pin 46 of the card-edge connector. This
allows the various PairGain Management System protocols to manage the HLU through the HMU-319 HiGain
Management Unit. Whenever the HLU-231 is under management, the
MNGD
message displays periodically on the
HLU-231 front panel display.
Fuse Alarm
Pin 32 on the card-edge connector is a Fuse Alarm that is driven to -48V through a 1000
Ω
resistor whenever the
onboard fuse opens.
System Alarm Relay Output
The normally open alarm contacts available across pins 20 and 21 (
) comprise the HLU-231
system alarm output. These alarm contacts close for any system alarms condition. This alarm contacts also close
if power is lost or removed from the slot, providing fail-safe relay output. See
for
further information about system alarms.
Some HLU-231 features are affected when it is under management. Consult the management
unit practice for further information.
