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DisplayPort/DVI extenders


jcbrig00
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Has anyone had experience with using an active Mini DisplayPort to DVI adapter then running the DVI signal through an extender using Cat 5e? I assume if the extender is HDCP compliant then it should work, but I am always cautious of dropping in adapters. I've just seen to many black screens in my day. Any tips or relevant experience out there?

 

Should I just try to find a DisplayPort extender? Do they exist?

 

Thanks in advance!

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Has anyone had experience with using an active Mini DisplayPort to DVI adapter then running the DVI signal through an extender using Cat 5e? I assume if the extender is HDCP compliant then it should work, but I am always cautious of dropping in adapters. I've just seen to many black screens in my day. Any tips or relevant experience out there?

 

Should I just try to find a DisplayPort extender? Do they exist?

 

 

HDCP has nothing to do with this.

Theoretically this should work, but avoid extenders that draw power from the DVI connector,

because the ACTIVE DisplayPort adapters use it already, choose separately powered ones instead.

And as always, test, test, test. Your mileage may vary...

 

Regarding a DisplayPort extender, isn't the question if a large screen display device/projector with DisplayPort input exists?

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HDCP has nothing to do with this. ...

Of course that is correct.

HDCP (High-bandwidth Digital Content Protection aka High-Definition Copy(right) Protection)

is data that comes from the video source (in this case the WATCHOUT display computer's graphics card).

WATCHOUT does not generate HDCP and therefore it should not be an issue.

 

Now if you were feeding a digital input signal that includes HDCP to a capture card to be displayed in WATCHOUT

(Blu-Ray players or cable TV converter boxes are common exampes of digital signal sources

that may pass HDCP data integrated with the copyright protected video content)

the capture card receiving the digital signal will honor the HDCP data

and refuse to provide the signal to WATCHOUT.

This is native to the input capture card hardware and its driver and

WATCHOUT can not alter that behavior.

 

-----

 

But a different issue may cause bad behavior with extenders - EDID (Extended display identification data).

The graphics card and the display must exchange information on the capabilities of the display.

If the display EDID is not available to the graphics card's output connection,

the graphics card will literally shut down that output and refuse to provide a signal.

If the EDID data from the display is distorted or incorrect,

the graphcis card may output, but may refuse to provide the correct resolution.

(WATCHOUT would report that as a resolution mismatch or resolution not available).

 

This EDID handshake behavior between the display and the graphics card output

is native to the graphics card and its Windows driver,

there is nothing WATCHOUT can due to override that function.

 

That said, EDID data distortion is such a common issue,

that third party devices to manage the EDID data independent of the display and its connection

are available from a wide variety of vendors.

An EDID managment device essentially isolates the data from the display,

and instead provides the data to the graphics card directly from the EDID manager,

even if the display is powered off!

The EDID manager is commonly connected directly to the output of the graphics card,

before it is extended / connected to the display.

This provides a much more stable environment to the graphics card, making it far more reliable.

 

We have seen EDID failures occur often with digital display connection extenders.

 

We have even seen it occur with simple digital short copper cable display connections

where the display's native EDID is corrupted or just plain wrong.

Was far more common issue "back in the day",

even display / projector manufacturers notorious for this problem in the past

have pretty much cleaned up there act with current offerings.

 

If I were shopping for a display extender, I would strongly consider

combination extender / EDID managers.

Barring a combo solution, I would always add an independent EDID manager

when using a dedicated digital display signal extender.

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  • 2 weeks later...

I have a similar problem, currently 7 of my deployment sites are using HDMI extender by CAT5e/6. I have used cheap cheap extender, some are dual CAT6 for one video signal, some are just single CAT6, but most of those sites I used Gefen ToolBox. Then I have used Vista and Win7, graphic card I used ATI and Nvidia and even Quadro card. All those sites I do experience black screen, around once a day... but consider if it is a 6-display computer system, there are around 6 times a day!

 

The strange thing is black screen seems only happens when the video is paused. My system is at idle/pause status most of the time, a play cue happens maybe after 1~3 hrs. If I set the video in loop mode, which I tested for 2 days, there are no black screen. And most of the time it is a blue screen (video loss/sleep?) before black screen. I have already followed those tween lists and also turn off any sleeping features in windows.

 

I can see in windows display properties, windows can recognize those projectors, sometimes it even states the model number! Therefore I assume it is not EDID issue....maybe I'm wrong? Any guru can advise?

 

Thanks in advance!

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  • 4 months later...

Hello

I also have a similar problem.

I have 29 display PCs (Win XP, Catalyst Control Center 12.1 + ATI HD Radeon 5670) sending video output to Sanyo DET100, DHT100, DLP100 & DWL2500 videoprojectors (VP) through HDMI over Fiber Optic (50/125) by the means of HDMI - FO extenders (Crestron HD-TX-1F / HD-RX-1F).

Some VPs show "loss of signal" either during a show or when idle (ie watchout is launched on-line but no task displays video on the VP).

And sometimes the video card driver makes the PC reboot (Catalyst Control Center documentation says the driver can make the PC reboot if it cannot handle some errors).

Any hint to tackle the problem ? Would you recommend to use the DVI port instead of the HDMI port on the video card ?

I can see the EDID in the registry, & Catalyst Control Center shows the appropriate display model.

Thanks in advance.

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  • 4 years later...

Hi all,

 

This is interesting because I am having the same issue. I am running just 1 display machine that is out putting to 2 Barco RLM W12 projectors and 1 computer monitor. It seems that when WO is in a pause state or idle the projector receive black for 1-5 seconds or loses signal and are sent into search mode looking for a signal. Not sure if the is related to EDID but I am pretty sure the Gefen DVI ELR lite extender over cat5 has EDID management, at lease it is set to use the downstream EDID.

 

WO 6.1.4

Windows 7

 

Any thoughts why this is happening?

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