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Snell's Centra

Significant economic pressures to reduce costs and to do more with less have pushed broadcasters to establish centralized multichannel facilities with an increased channel count per operator. To institute control and monitoring that covers the entire workflow and effectively reduces on-air errors, broadcasters traditionally have invested heavily in ongoing customized development. Shrinking budgets, however, are demanding that broadcasters now consider off-the-shelf packages capable of approaching a similar level of integration at a reduced cost.

Ideally, a single control and monitoring system gives operators the highly customized tools they need for scheduling day-to-day tasks — as well as for rapid identification and resolution of unexpected issues — while remaining simple to maintain and configure in house. Snell's Centra control and monitoring system takes advantage of today's technologies to make this possible and offers operators the functionality they need, when they need it, regardless of where the broadcast systems involved are located.

A comprehensive suite of tools that together comprise a vendor-agnostic control and monitoring system, the system represents many years of development of broadcast system control and network management monitoring systems, covering the full spectrum of broadcast and IT devices. The suite delivers systems covering four critical areas: configuration, system monitoring, system control and content monitoring. (See Figure 1.)

Integration and interoperability

A comprehensive control and monitoring system demands that a full-featured system interface directly with third-party vendor-specific protocols over serial and IP links, as well as allow more traditional monitoring via SNMP and GPI/Os. This approach is critical because, though it has been widely adopted as the way to achieve third-party integration, SNMP was never designed to be a control protocol. Even for monitoring purposes (as with broadcast), there remain issues in that key types of status extraction are still unique to each manufacturer — and even unique among different product lines from a single manufacturer.

The system solves this challenge through a combination of generic configurable translators that can be scripted to work with a wide range of protocols and full-featured implementations of native protocols. The system's resulting scalability and its ability to integrate with broadcast, IT and other key devices allow it not only to grow incrementally along with the technical and business needs of the broadcaster, but also to present the information in a broadcast-centric way to suit the particular user.

The system can be completely configured and delivered either by Snell staff, a systems integrator or by the user. A combination of an initial deliverable, engineered by Snell or the systems integrator, with ongoing maintenance by the user is often the ideal. This approach provides a balance that offers initial efficiency and the reduction of ongoing customization costs by giving the user the ability to upgrade and modify the system.

Flexible control and monitoring interface

The interface can be configured to show the same information to different users in different ways that are specific to their tasks. Whereas an in-house engineer may be relayed full system information in a physical rack layout with functional connections, playout operators will be provided with just the channels and the parameters (e.g., specific router destinations, aspect ratio converter, etc.) over which they actually have control. The system allows combinations of controls to be grouped onto a single screen. Without this capability, the operator frequently has to switch applications or PCs to achieve the same result.

Through this interface, it is possible to configure the satellite positioning to point the dish to the correct signal, and then process the feed through the correct channels of an IRD before routing the SDI signal through the facility. (See Figure 2.)

One of the features of the system is its ability to hide the complexity of routing from an operator. Typically, a user must know the source and destination numbers of a given device to route it into the signal path. The system, however, allows some back-end configuration of the system to be programmed in at the configuration stage (using a graphical representation of the system). The operator GUI then presents the devices in groupings (e.g., upconversion, ARC, logo insertion) determined at the configuration stage so that the user can quickly search through and find an unused device and complete the routing path in a simple operation. This relies on the devices being connected to the router from both input and output.

Single button presses can replace one device in the chain with another. The same screen can be set up to provide access to a subset of full controls for the actual devices that have been routed, allowing the user to set his or her parameters. Together, the simplicity and functionality of the user interface save time and reduce the risk of error.

Extended control and monitoring capabilities

While many other systems monitor only the health of power supplies or tally information, Centra can look at the actual content of the picture and the metadata, in turn providing the user with much more powerful feedback. By using information available from a playout schedule such as the expected genre of program content, number or type of audio channels, aspect ratio, and presence and location of logo, different settings may be applied at different times to ensure the correct settings are applied for processing devices and that optimal monitoring can be enabled at each point in the schedule. This approach can significantly reduce false alarms and improve notification of genuine problems, preventing costly mistakes from being aired.

The system allows the user to program powerful rules that enable the automatic setting or correction of conditions. In many broadcast chains, the final point of the trasmission path consists of a failover 2 × 1 switch. With Centra, there are different ways of ensuring the signal continuity including intelligent rules within the hardware module itself, using the Hyperion or intelligent Snell router inputs to detect the signal content through any device. Hyperion can be configured to detect and alarm on a number of different failure modes, including complete black and picture too dark, full freeze or motion level too low, loss of audio, or wrongly assigned tracks. (See Figure 3.) When incorporated into Centra, this information will not only alarm and indicate the error, but also automatically switch to the backup signal path. This reduces the time spent transmitting corrupted or missing information to viewers, thus minimizing penalties and providing time for resolution of the problem.

The rules engine may be configured for any number of simple or more complex operations depending on a combination of conditions. For example, if a router input is required to be HD, but the external modular device (or the router itself) finds the input to be SD, the system — if it is connected to known inputs and outputs of the router — can automatically insert an upconverter into the path and adjust video input parameters to the correct values. This can ensure optimal usage of expensive converters in a system by using them when they are required rather than requiring their permanent installation on every chain.

To aid remote and/or centralized analysis, using the combination of Hyperion and Centra allows low-resolution streaming of video and audio proxies — along with the metadata measured from the remote signals — across WANs and LANs. The video with the error status allows the operator to see both the control settings and the impact of those settings within a single view. The system serves as the primary and, ultimately, the only operator interface with equipment. It alerts the operator of any problems across the broadcast chain immediately and provides the interface through which to put things right.


Centra's intelligent control and monitoring capabilities reduce the total cost of ownership and downtime while increasing productivity. It allows more channels to be monitored, focusing operators' efforts on true areas of concern. The real-time system does so by addressing and simplifying not only configuration of Snell devices across the workflow, but also operational control of the broadcast chain and enterprisewide monitoring of signal paths and all equipment. Providing a comprehensive third-party driver library, the system brings a new unified approach to controlling media technology.

Kirsty Aldridge is product manager for control and monitoring at Snell.