Teledyne HPAC-2005, Operation Manual

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60 205356 REV T 3 RU SSPA Chassis Operations Manual
If the Master Module develops any kind of major fault condition, it delegates its Master
privileges to the unit which is next in N+1 ranking and becomes a slave unit. This type
of control architecture eliminates a single point of failure and achieves true N+1 system
redundancy.
The Master Module is designated with a lit Online indicator and VFD display showing
the overall system state. See
Figure 2-15
.
The Online indicators of the Slave units are always turned off and the VFD displays the
message shown in
Figure 2-16
.
Any unit that develops a major fault condition will be automatically muted to avoid any
side effects of the faulted unit on overall system performance.
The Master Module offers two extra informative menu screens for displaying system
level information such as: System forward and reflected power levels, system wide
gain or attenuation, amount of faulted SSPA chassis in the system, etc.
To avoid control conflicts, slave units are forbidden to gather system-wide information,
therefore these system wide information screens always hidden on N+1 Slave units.
2.4.2 Controlling System Operation
The N+1 system is under the control of the Master Module at all times. Any system-
wide settings changes (local or remote) need to be performed on the Master Module. If
a setting is adjusted on a Slave unit, the Master Module will erase and override it with
the current system setting.
Some settings are not controlled by the Master Module because they are used for unit
identification or required for local adjustment during maintenance. Settings such as the
SSPA Network Address, N+1 Address, and IP Address are not enforced by the Master
Module and need to be set individually at every SSPA chassis.
The setting for enabling/disabling/sizing the N+1 system is also not controlled by the
Master Module. This setting allows the user to virtually remove individual SSPA units
from the N+1 control array for maintenance and troubleshooting.
Figure 2-16: Front Panel Display, Slave Unit (Online Indicator Dark)
Figure 2-15: Front Panel Display, Master Unit (Online Indicator Illuminated)