Harris Constellation, Installation & Maintenance

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Harris Corporation Constellation™
System Features 1-17
INTRODUCTION
System Features
Protection Switching
The Constellation Radio can be configured with the following protection
system.
•
Transmitter Assembly
•
Receiver Assembly
•
Power Supply
•
Modem
•
High Level Mux
•
M12 Units
The primary set is operating, while the other set is operating in a monitored hot
standby (MHSB). When one of the units in the radio shelf fails, the SPU
Controller implements an automatic switching algorithm. Switching is
nonrevertive; that is, when a failed unit is replaced by a working one, an
automatic switching from the standby unit to the working unit does not occur.
The exception is the M12 Unit protection, whose nonrevertive or revertive
mode can be selected through the Keypad.
All units except the M12 Units are 1+1 protected. M12 Units are 1:N protected.
If one (or more) T1 channel fails on an online M12 Unit, all 4 of those channels
are switched to the standby M12 Unit. This switching action causes a
momentary disruption of traffic on all 4 of the T1 channels.
The HLM provides errorless switching for the receive paths. Although errorless
switching is provided on all MHSB radios, its primary purpose is for space
diversity receivers. Switching several times a day is normal for space diversity
receivers. Receiver switching is errorless with up to 200 ns of delay between
receivers.
Automatic Transmitter Power Control (ATPC)
ATPC
Full ATPC functionality is a supported feature of Transmitter Assemblies,
Model 3 and higher, and has a guaranteed 10 dB range. ATPC is not supported
for Model 1 and Model 2 Transmitter Assemblies.
Refer to Appendix E for identifying the model numbers.