USER MANUAL
HCO-3931 |
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HCO-3931 12G/3G/HD Change Over with Clean Switch and ALC
Introduction
The HCO-3931 from Grass Valley is a 4x1 12G/3G/HD SDI change-over that supports 16 channels of embedded
audio and metadata. The card
can perform a video and audio “clean and quiet switch” between sources. In the event
of a power failure, the PGM signal is protected by a bypass circuit fitted on the rear panel, maintaining the integrity of
the selected MAIN or BACKUP signals at the output, and it is fully controllable via GPI. Two rear panels are available
with different bypass circuits, the HCO-3931-3DRP-H offers an active bypass that retains PGM signals for at least 48
hours while the HCO-3931-3TRP-HR uses 12G SDI rated bypass relays for extended protection.
At the core of the HCO-3931 versatility, a powerful automatic mode rules engine takes the guesswork out of
establishing which input will be routed to the outputs. By simply selecting which signal analysis probes to enable, con-
figuring the severity of each probe’s impact and optionally removing one or both Emergency inputs from the rules
engine’s consideration, you effectively instruct the card how to compute the relative health of each input based on its
weight and the probes statuses. This in turn enables you to effortlessly create a wide variety of failover mechanisms.
Change-over between inputs selection can also be performed manually, where any four sources can be selected from
the Densité controller, the iControl/GV Orbit software, or simply by using a GPI. A GPI can be connected to an
automation system or any simple GPI control panel. The GPI outputs give the status of the selected source, allowing
tallies to be triggered.
The HCO-3931 provides two 12G/3G/HD outputs: Program (PGM) and Preview (PVW). Each output is available on
two connectors (signal copy). The PVW output is user selectable to follow the main PGM output or any of four video
inputs.
Grass Valley’s next generation 16-channel automatic loudness control (ALC) option, HCO-3931-OPT-ALC, can
eliminate objectionable loudness variations between programs and commercials even better than with previous ALC
versions, thanks to the addition of an independent dynamic stage consisting of a fully configurable input compressor
and a new true peak output limiter with 1 ms buffer protection.
This new Densité card fully complements our line-up of 12G SDI products such as the HDA-3961 single/dual 12G DA
with optional fiber connectivity, MDX-3901 12G 16 audio channel AES/MADI embedder/de-embedder, XIP- 3901
SDI/IP agile processing platform and our other Grass Valley products.
Based on the proven Densité modular framework of over 100 cards, the flexible, space-efficient HCO-3931 is a 3 RU
card and is available with a two or three slots rear panel. With flexibility to configure up to 12 HCO-3931 change-over
cards per Densité 3+ FR4 frame with the two-slot rear panel, the Densité platform scales to a density of twelve 12G
SDI change-over cards in a 4 RU frame. This means space- and cost-efficient scaling for today and tomorrow.
The HCO-3931 is configured, controlled and monitored by GV Orbit from Grass Valley. It can also be configured and
controlled from iControl systems.
The HCO-3931 targets emerging needs to provide changeover with clean switch and optional Automatic Loudness
Control for single-stream 4K UHD signals using 12G SDI. The HCO-3931 is designed for a wide range of applications
where bullet-proof mission critical signal distribution is required for OB trucks, production studios and playout facilities
as shown here:
