Verilink 2000 (34-00182) Product Manual - Manual (Page 26)

2-14 I NSTALLATION
Chassis
Network
Management
The operation of the EM8000 and the 8100A unit in the 12-slot chassis is similar
to the stand-alone operation. Within the chassis, each element is physically
connected to the next element in a daisy-chain fashion. Signals from all modules
are gathered and presented on consolidated 6 -pin modular connectors on the rear
panel, labeled NMS IN and NMS OUT. The front panel SUPV port operates in the
same fashion as in the stand-alone unit.
When used in the chassis, the communications bus is automatically tied into each
unit, allowing single point interfacing to the chassis. Cards may be inserted and
removed from the chassis without rewiring the communications bus.
Communications are restored by shorting contacts on the backplane when a slot is
vacant.
Alarm
Connection The stand -alone unit and the chassis modular unit provide rear panel alarm relay
contacts. These dry (isolated) alarm contacts permit connection to a remote
indicating device.
Stand-alone
Unit
The connection for the stand-alone unit is made on pins 5 and 6 of the
Power/Alarm connector as shown in Table 2-12.
Pin 5 is configured to operate in either a normally open (NO) or normally closed
(NC) mode as determined by the setting of the alarm relay jumper shown in
Figure 2-8. This jumper is located on the circuit board.
NO and NC refer to the contact’s relationship to the common contact under a no
alarms condition. Move the jumper to NC for normally closed operation (opens on
alarm) or to NO for normally open operation (closes on alarm). Make connections
to the contacts using 20 -gauge stranded wire (or similar). Contacts are rated at 0.3
amperes AC or 1.0 ampere DC.
Internal Audible Alarm
The CSU is equipped with a piezo buzzer that indicates an alarm condition. This
feature is particularly useful for sites where the unit is used in a stand-alone
application and is not supported by a management system. A simple continuous
Table 2-12 Power/Alarm Connection
Pin Function
1 48 VDC return
2 Signal Ground
3 -48 VDC
4 Frame Ground
5 Alarm Contact
6 Alarm Common
NO
NC
Alarm Relay
Figure 2-8 Alarm Relay Jumper