February 11, 2005

Flight Test Control Room Video Distribution

Often the requirements for flight test control rooms include video distribution systems.

Video from both inside and outside the control room is distributed throughout the control room. The video signal from each computer workstation and each outside video source is sent to a central video distribution switch. The output of the video distribution switch is routed to large video display screens and to monitors located at locations throughout the control room.

An RGB matrix video distribution system for a control room with 40-50 users may cost more then half a million dollars.

And the costs for video distribution systems in control rooms have continued to climb even higher….

Computer workstations today output multiple video channels (dual monitors per workstation) so this means the video system has to support additional inputs then the past. Or you get into a confusing situation of which monitor from the computer is going into the video distribution system and which one is not.

Costs rise even higher if a digital high definition video distribution system is used in the control room. During the last several years the broadcast industry has moved from analog to digital high definition video switching systems. RGB matrix systems can be used to distribute high definition video as analog signals.

But if you move to a digital high definition distribution system, then the RGB video output of each computer needs to be converted to a digital format. The output of the video switch then has to be converted back to analog for display on most computer monitors. The costs for a video distribution system like this can rise close to a million dollars. This is because in addition to the cost of the matrix switch, each channel of video requires a conversion box to convert from RGB video to digital high definition from the computer (two if you have two outputs). Another conversion box is required to convert the high definition from the switch back to RGB. These conversion boxes cost several thousand dollars.

The question is are you distributing video to support flight-testing or are you building a big home theater system!

And do we still need a large video distribution system like this anymore in flight test?

Can we get by with something smaller and cheaper?

You bet.

If you can host the same display software like the Symvionics IADS software on most computers in the control room you do not need a large video distribution system.

If the same software is available on each workstation then any user could bring up any display available in the control room.

This is a service the video matrix switch provided in the past. In the past we used RGB matrix switches to provide content for the user’s “second monitor” Now every workstation built today has a graphics card capable of driving two monitors locally so driving the second monitor with the video switch is no longer needed.

I know your saying what about that one special computer that needs it’s video distributed around the control room?

So go ahead and buy a smaller video switch like the Pesa Premiere matrix switch.

In a downscaled system like this, several additional computers can be purchased to provide dedicated content for the large video display screens in the control room.

And the outside video sources can be either connected to the small matrix switch talked about above or by directly to the large video display screens. You can use the remote control that comes with every large video display projector or screen to change the video sources presented on the screen (just like you do at home).

So what about high definition video?

If it is not among the video sources received in the control room, then buy computer monitors and large video displays that support high definition.

In the future high definition video will most likely be an outside video source. This video will probably enter the control room as video telemetered from the test vehicle or as video from a ground tracker. This video can be distributed using the same small matrix switcher used above.

And by that time an encoder like this one from Vbrick Systems may be available for high definition video. This would allow the transfer of high definition video over IP networks.

Then a standard application like Windows Media Player could be used to view this video on each workstation.

Do other alternatives exist for systems like this in the control room?

What about Keyboard Video Monitor switches used in computer data centers? If a KVM’s can support resolutions of up to 1200x1600 then it is a good alterative to a RGB switching system.

This company Agelec is on the right path combining RGB matrix switches and the KVM into a single product.

KVM’s also provide the added benefit that the computer workstations could be relocated to a secure area and only the mouse, keyboard, and monitor would be located at the user location. By moving the computer to another area, the console size can also be reduced in size because it does not need to house the computer. Power and cooling requirements for the control room are also reduced because the computer systems are located in another location. If a computer workstation fails during the test mission the KVM can be used to call up a hot spare workstation. So if support for higher resolution video improves on KVM’s this could be the option for the future.

That’s all for now.


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