Ross 4500DR-204-03, Руководство пользователя

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ACO-4500 User Guide (v3.0) Before You Begin • 13
Before You Begin
The ACO-4500 is designed for high reliability Master Sync operations where two SRG-4500 units are provided as
a fail-safe Primary and Backup pair. The ACO-4500 provides automatic fail over to the wide range of SRG-4500
reference signals.
The ACO-4500 provides user-selection of reference sources. Automatic changeover may occur upon fault detection
in any active source.
The ACO-4500 is an in-line device without internal buffers. Switching for all channels is by mechanical relay. The
ACO-4500 also provides internal termination for unswitched BNC inputs.
The ACO-4500 includes 12 channels in a 1U rack. Each BNC channel consists of a Primary Input, a Backup Input,
and an Output. All BNC channel relays switch in unison upon fault detection in any active BNC channel,
front-panel command, or remote command.
In conjunction with the BNC channels, there are a number of unmonitored secondary channels available on
Molex® connectors. All secondary connector channel relays switch in unison upon fault detection in any active
BNC channel, front-panel command, or remote command.
The ACO-4500 uses signal amplitude as the basis for error checking. You can configure each BNC channel to
check for a different type of input. There is a selection of predefined checking levels relating to the various signals
that are supported:
• No Measurement
• Color Black (no ancillary signals present, i.e. only Sync and Burst)
• Color Black + VITC (with one or some ancillary signals present)
• 600mV Tri Sync
• SD SDI - LOS
• HD SDI - LOS
• 3G SDI - LOS
• 1V 10MHz
• 1V Sub-carrier
• 1V AES
• 2V Pulses - LOS
• 4V Pulses - LOS
For the common signals, a fault is reported when the input signal level falls below a predetermined ratio of the
nominal peak value. Visual fault indications appear on the front-panel display for signals from both the Primary and
Backup SRG-4500s. These indications remain on until cleared by the operator.
For other signals, a simple “Loss Of Signal” (LOS) detection is performed.
The signal reference amplitudes used for fault detection are programmed during factory calibration. The ACO-4500
includes dual power supplies, which provide power supply failure redundancy.