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macrumors newbie
Original poster
Jan 11, 2014
I have an ADT security system that uses a DVR for my security cameras. ADT told me I can display my video through my 27" IMAC by connecting the IMAC via the mini-display port to the VGA connection. I'm using a Rockfish mini display port to VGA adapter. When I make the connection the IMAC starts switching display modes. Doesn't display anything from the DVR.

Is there a way to make this connection work?




macrumors 601
Oct 5, 2003
Dark Castle
ADT might think that you have a separate monitor.
Is there any software they gave you?
I think for the iMac to run as a monitor run it in Target Display mode.
If the DVR has a FireWire port that could be another alternative, most video devices with a FireWire port can output video signal you will need some software to display it though.


macrumors newbie
Original poster
Jan 11, 2014
ADT said the options would automatically display on the monitor once it was connected.

No fire wire connection on the DVR.

I will try the Target Display mode to see if that works,



macrumors 68040
Jul 13, 2008
I doubt this will work.

Am I correct in that you're trying VGA OUT to Mini DISPLAY POT IN?

And your adapter is probably directional; it's probably designed to change MDP TO VGA; going the other way requires more of a conversion, and I'm not sure you could get that to work even with an active converter. Even DVI on the other end of the TDM chain is fiddly, if possible. Generally TDM wants DP or MDP or TB on the other end. VGA out is sort of minimalist tech.


macrumors G3
Mar 26, 2008
West Suburban Boston Ma
What 27" iMac are you talking about? 2012-2013 iMacs only accept thunderbolt video in. If you have a current iMac, it won't work.

pre-thunderbolt accepts video in , but I don't think that would include VGA.


macrumors 603
Dec 19, 2004
You need to ask them if they have Remote Surveillance viewing software for the Mac. Also look at the DVR to find the make and model to see if the manufacturer offers the software if ADT can't help you. My guess is the first tech you speak to at ADT will be clueless and your call will need to be upgraded to someone that knows a little then finally someone that actually knows what is going on.

You will likely need to buy a VGA monitor to connect to the DVR. For the purposes of viewing and programming. As you will likely need to program it to be accessible by remote software. Also if you want offsite viewing you will need the monitor to program it's FTP functions.

The DVR may also have the ability for viewing and programming via a web interface. I would pick up a VGA monitor anyways. You can most likely get a 15" or 17" for dirt cheap at the Goodwill. If it supports it also get a keyboard and mouse rather than programming it with a remote control.

Depending on the DVR it may also have an app in the app store for iPad and iPhone.

If your DVR is a Matrix you can try their software.


macrumors 68040
Sep 8, 2011
Eureka Springs, Arkansas
Definitely can't connect a VGA Out to an iMac, using Target Display Mode or any other means, regardless of which iMac it is, without additional hardware.

If ADT doesn't have a way to connect via IP or USB, and the only means is through the VGA port, then you need a VGA video capture device like this one. That would let you view, record, etc. the security footage on your iMac.

If you just need a monitor & don't specifically need the footage on your Mac, a VGA monitor would be cheaper.
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