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Author Topic: Using Multiple Laptops With A DVI Switcher Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 02-04-2010 06:06 PM                        I am posting this incase anyone runs into the same issues I have... Using multiple macbooks on a 4 to 1 DVI Switcher fed into a NEC1600 you run into a problem where everytime you "take" one of the sources it break's the connection to the others causing each macbook to "re-set" itself as it no longer sees the NEC as a "display" so everytime you "take" a source you have to wait while it recognizes the NEC and re sets itself. Now to get around this we used DVI to cat. 5 converters (one on the macbook end and one on the switcher end) to send the signal from the macbook to the switcher. What this does is causes the macbook to only see the DVI converter instead of the NEC. Because the DVI converter is before the switcher you never "break" the connection with it so the macbook's never have to "re-set" themselves. I hope this will help someone out someday.  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 02-04-2010 06:58 PM                     I just came across the same issue when trying to build a preview monitor solution for a digital projector with various sources. We found a HDMI 4:2 Matrix which operates quite nice - but indeed with every switching it reconnects the whole matrix in- and outputs, even on connections that are not affected by the intended switching. I found this to be no real problem with BlueRay Players, SAT-Receivers, etc., but it is a real pain in the ass for computer sources - in this case, a Windows PC was connected through it's DVI-Output to the HDMI matrix. Every switching disables the secondary monitor connection. It will usually come back, and you can disable the notification that comes up - but, the running application then sends its window to the primary monitor and will not return it to the secondary monitor by itself, even if the secondary monitor output is reenabled by the matrix within fractions of a second after the switching. That's a huge difference to the behaviour with analog VGA connections. We actually solved this by using the analog VGA output of the computer connected to the HDMI matrix through a (slightly absurd in general...) VGA-DVI converter (about 50US$). Now only the VGA-DVI converter get's disconnected through the switcher - but not the PC. Whatever you do with these DVI/HDMI switching solutions - don't take anyhing for granted. Try before you buy. You will be surprised or disappointed multiple times... With HDMI Switching/Splitting, you will also have to take into account other features of your gear, like 1080p24/p50/p60, HDMI/DVI colorspaces (RGB, YUV). Our beamer applies certain presets to it's various input sources automatically. Now that's normal. But I also found out that it applies separate presets when the source on the same input switches from HDMI-RGB to HDMI-YUV! It chose a different colour/gamma setting when I configured our BluRay Player from RGB to YUV on it's HDMI. Analog switching is A LOT easier! - Carsten  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-05-2010 10:14 AM                     Gosh I just want to chuckle so loud at you guys. Welcome to my world! DVI/HDMI are indeed riddled with such Bullshit! The fault is in the device that it wants to do an EDID handshake and without that, it presumes no DVI and scampers off to analog. You MUST use devices with EDID emulation. That is, the device must always let the source "think" it is talking to your projector. Extron makes EDID minders that are stand-alone http://www.extron.com/product/product.aspx?id=edid101d&s=0 The only switchers one should even consider are ones that maintain that EDID thing like: http://www.extron.com/product/product.aspx?id=swdviplusseries&subtype=231&s=3 HDMI has similar issues but with HDCP thrown in. Also, if you have multiple outputs...each thing that comes on line (like a HDCP compliant monitor) will handshake and possibly interrupt the signal until all agree. When the EDID handshake happens...it negotiates the common format that all can handle so make sure ALL devices are capable of handling what resolution and frequency you want. Isn't digital fun? Steve  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 02-05-2010 01:03 PM                        quote: Steve Guttag Gosh I just want to chuckle so loud at you guys. Don't Laugh At Me Steve!!! The best part is that if you do what I said above then take the output of the switcher into a DVI to SDI converter (like the one made by black magic) for a long run from say the stage into a BNC jack to get the signal back up to the projector the converter will not operate as it does not see any computer connected to it (even though it is powered) We have Cat. 5 receptacles in our stage boxes so I tried to use another DVI to Cat. 5 converter but the run was too long to get any signal back at the booth. I HATE this digital video stuff! I could probably use an adaptor to convert the output of the DVI switcher to VGA and then use Ballun Send and Receive boxes to send the signal back to the booth but then that would defeat the WHOLE purpose of having a high resolution digital signal. (A Macbook looks REAL nice set at a high resolution wide aspect ration on our screen from our NEC1600. I love to show people who come in for presentations expecting a tiny image for thier powerpoint etc... how big the image is almost filling our screen! I would give anything for good old passive analog switching equipment!  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 02-05-2010 03:23 PM                     We can not afford to spend 400-500 Bucks just for the basic switching part of a monitoring solution. We just don't use it often enough. I guess that some cheaper KVM solutions would work as well. At least as long as HDMI is not in the game. Whatever - try before you buy or make sure you can return the unit if it doesn't work as expected! And expect it not to work the way you expect it! And expect to spend more on a working solution than you expected! - Carsten  |  IP: Logged

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