DK-Technologies explores the separation of client and server for all incoming signals.
As more and more broadcast facilities look for ways to reduce cost without compromising quality, DK-Technologies has been studying its own area of the industry to see if changing the way people monitor audio and video might help them achieve these twin ambitions.
Looking at the methods employed by broadcasters, we realized that although audio and video technologies are moving inexorably closer, broadcasters' working practices have not changed. They still install multiple meters, and they still use expensive router ports to achieve multichannel metering on a single meter. Seeing these complex installations, we realized that what broadcasters needed was a practical system that could deliver the same results more simply and more cost-effectively.
Exploring the options
Initially we thought about providing a basic remote but rejected the idea almost immediately as we felt it was not sufficient to meet users' needs. A simple remote might allow full interrogation of the host metering or monitoring device, but ultimately it reflects only the last button push. This can cause major headaches (and substantial delays) if the engineer requires the host device to check a problem but the operator needs it to carry on doing something else while the problem is fixed.
Instead, we came up with a system that allows engineers in one location to operate the host device (the server) as they wish and see all the information they require on the built-in display. (See Figure 1.) At the same time, in a separate location, another engineer can use a specially designed remote client unit to access the same system but see different information on the display. (See Figure 2.) This means both ends of a link have independent control over what is shown.
To achieve this, the meters now have DVI or DVI-over-Ethernet connections so users can easily connect to external devices, local area networks or remote controls. With this new system, we have used a DVI multiplexer interface, which allows the user to install multiple HD/SD video channels and associated audio in a central technical area while also providing the ability to measure those signals somewhere else in the facility via the DVI link. Through the use of a simple selection panel, the user can monitor and display any of the incoming signals at the remote master control room. Taken to the limits of the existing system, the maximum number of HD/SD video signals is 32 with up to 128 audio channels.
The entire system is based around the PT0700 series waveform monitors, which provide a self-contained platform for analyzing and monitoring video and audio signals. (See Figure 3.) The signal interface is modular and provides means for accepting multiformat digital video signals (SDI), digital audio signals (AES), analog audio signals and analog timing reference signals (blackburst or trilevel). An extensive range of real-time analysis tools are provided for validating the monitored signals, ranging from multichannel video waveform displays, vectorscopes and timing measurement to audio loudness levels, surround-sound visualization, Dolby decoding and much more.
Due to its highly scalable design, the PT0700 series server units can service two independent control surfaces. Each control surface can operate on a shared pool of input sources and provide simultaneous analysis and control. When operating the server unit, the user can select which control surface to assign to the server front panel. Furthermore, the assignment of control surfaces can be changed dynamically, enabling the operator to toggle between the control surfaces by simply pushing a button.
Attaching a PT0700R client panel to the PT0700 series server unit introduces a whole new dimension of flexibility. The client panel is essentially a hardware unit containing the user-interface part of the PT0700 series unit; in other words, it has a similar display and front panel. The client panel must be connected to a server unit to work, since it relies on the signal sources and processing resources in the server unit. In this type of server/client system, the control surfaces can be assigned independently, which means two operators can use the server user interface and client user interface simultaneously — almost as if they had two separate units fed with the same input signals. The connection between the server unit and the remote client unit is a Digital Visual Interface (DVI-D), known from computer displays, etc. To attach a client unit to a server unit, all the engineer has to do is connect a standard DVI-D cable. By using this interface, it is also possible to separate the client and server units by several hundreds of meters using just standard DVI extension solutions that are readily available on the market.
The separation of the client and the server unit makes it possible to install the server unit in an equipment room and the client unit in an operator room. This can simplify the cabling in the case of many signal sources, since the server unit can be installed in proximity of the signal sources, having only a single DVI-D cable run to the client unit at the operating position.
Richard Kelley is director of sales and marketing for DK-Technologies.