Comtech EF Data UT-4514F Spezifikationen PDF herunterladen (Seite 27)

UT-4500A Series Upconverters Revision 1

Introduction MN-UT4500A

1–3

1.2.1 Applications

The upconverter operates over the RF frequency range with a typical gain of 35 dB. The RF

output level is +10 dBm at 1 dB compression allowing the capability for longer cable runs to

compensate for splitting networks without adding options such as external line amplifiers.

The phase noise performance exceeds the Intelsat phase noise mask for IBS and IDR services by

more than 9 dB. This allows high capacity earth stations to add more demodulators and still

meet transmission standards. The close-in phase noise is also very low. This makes the

upconverter ideal for low bit rate digital circuits such as used in DAMA hub earth stations.

A selectable EIA-232C or EIA-485 remote control serial communications connector interface is

provided on the rear panel of the upconverter. All configuration control, status retrieval and

adjustments are available as ASCII commands through the serial interface, or as local operator

input command to the upconverter.

A detachable Input/Output Module (IOM) can be mounted in the rear of the upconverter chassis

for switching the RF output for single thread operations, or for testing the output of the unit.

The connectors for the IOM are located on the rear panel.

In applications where upconverters are "Daisy Chained" together to provide distributed online

protection switching to a backup upconverter, the IOM is replaced with a detachable Transmit

Switch Module (TSM). The TSM contains RF and IF transfer switches. Type N connectors are

provided for the RF loop, and 50 or 75 ohms BNC connectors are provided for the IF loop.

The "Daisy Chain" configuration is designed to chain the IF input and RF output of up to twelve

(12) online upconverters together through TSMs terminating in a backup upconverter. When a

fault occurs in an online upconverter, the TSM in the upconverter with the fault is commanded

to switch to the backup upconverter.

The backup upconverter performs the fault detection, self-reconfiguration and the logical

switching functions. If the backup upconverter has a fault, it will not attempt to perform the

protection-switching task. If the backup upconverter does not have a fault, it will assume the

frequency and attenuation of the faulted online upconverter, and compensate for the chain

losses.

The backup upconverter in the "Daisy Chain" communicates with the online upconverters

through a high speed (data interface) bus (HSB). When faults are detected, the backup

upconverter re-configures itself to replace the online upconverter with the fault. The backup

upconverter also uses the HSB to monitor configuration changes made to the online

upconverters by either remote control or front panel command inputs.

Changes in frequency, attenuation or polarity are entered into the backup table as they are

made, as well as information from new online units. The HSB does not interfere with the remote

control communications link for access to any of the converters in the "Daisy Chain".

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Comtech EF Data UT-4514F Spezifikationen Seite 27