Help needed with getting feed from video intercom

[DaveSan 0]

Hi everyone,

 

I'm new to this, and I'd really appreciate your help!

 

My apartment block has a video intercom system. The camera is mounted next to the main stairwell door and each apartment has a handset / screen for viewing what the camera can see (see attachment "1Handset.jpg").

 

We've been having problems with burglaries/vandalism in the area, and I'd like to be able to grab frames from the camera for recording on my PC. Looking at the back of the handset (see attachment "2Connections.jpg"), I see that there is a black coaxial cable coming from the camera. Would it be possible for me to just connect this coax cable to a DVR card in my PC, or am I over simplifying things? Perhaps I should start by trying to connect this cable to my TV?

 

Any help is much appreciated!

 

Thanks,

 

Dave

 

P.S. To give you an idea of my experience: I'm very computer literate, but less knowledgeable about electronics/CCTV etc. I'm more than happy to learn whatever is required though.

[Scruit 0]

I'm not an expert, but...

 

Does the video phone have only the one 'channel' image? ie can youswith over and look at a different camera, dofferent door etc? That would suggest the image is modulated using RF. Othewise it's likely to be just a simple image that can be piped into an RCA connector on your TV/vcr/DVR

 

I woudl test it with a cheap device that you don't care about damaging first - ie an older VCR using the LINE IN video port.

 

For a permanent install I'd probably run it into a $20 video distribution amplifier (about the size of a cellphone) and use one of the two outputs for the phone, one for the DVR. If you use a passive splitter then you may find the image gets darker or loses quality. If other folks notice the signal quality loss then they may call a tech to check it out.

 

 

Is the video screen always on? Or can you turn it on whenever you want? Or does it only turn on when someone call you directly? Just wondering if that coax is always carrying the signal.

[DaveSan 0]

Hi Scruit,

 

thanks for the prompt response!

 

Does the video phone have only the one 'channel' image? ie can youswith over and look at a different camera, dofferent door etc? That would suggest the image is modulated using RF. Othewise it's likely to be just a simple image that can be piped into an RCA connector on your TV/vcr/DVR

 

Interesting question. Although the video phone itself supports 2 cameras, we only have a single camera installed. My old VCR has both an "RF" socket (I'm in the UK) and an RCA video socket, so I could try both.

 

I woudl test it with a cheap device that you don't care about damaging first - ie an older VCR using the LINE IN video port.

 

I hadn't considered that it may damage my TV - thanks for the warning.

 

For a permanent install I'd probably run it into a $20 video distribution amplifier (about the size of a cellphone) and use one of the two outputs for the phone, one for the DVR. If you use a passive splitter then you may find the image gets darker or loses quality. If other folks notice the signal quality loss then they may call a tech to check it out.

 

Good idea. The videophones have brightness/contrast sliders with a huge range, so hopefully they shouldn't have any problems with things getting too dark. If I get things working at my end, then I'll check that I haven't caused them any problems.

 

Is the video screen always on? Or can you turn it on whenever you want? Or does it only turn on when someone call you directly? Just wondering if that coax is always carrying the signal.

 

I can turn it on whenever I want and see what's going on, which suggests that the coax is always carrying the signal.

 

I'm going to drop by the electronics store tomorrow, grab some coax, and see what happens when I hook this up to my old VCR.

 

Thanks a lot for the advice. I'll let you know how it goes.

 

Dave

[DaveSan 0]

Is the video screen always on? Or can you turn it on whenever you want? Or does it only turn on when someone call you directly? Just wondering if that coax is always carrying the signal.

 

I've done some further investigation and you might have hit upon something here. The screen on the videophone switches off after a couple of minutes, and you have to press a button to reactivate it. I assumed that only the screen was shutting down and not the camera itself.

 

However, I've done some searching online and I found the installation manuals for the videophone and and door camera. I've attached a screen grab of one of the pages and highlighted the relevant part in red. It appears that the camera does indeed shut down and needs to be told to activate by the videophone (either because the videophone received a "call" signal, or the user pressed the "activate camera" button).

 

This means that I'd have to have something repeatedly sending the "wake up" signal to the camera. Perhaps this would be straightforward, but I'm not sure if I'm going down the wrong path here...

 

The other thing that I've realised is that the door camera and the videophone are both made by the same company, so there's a chance that the video format is something proprietary. Hopefully not though.

[Scruit 0]

Another thing to consider: If someone comes to the door and presses the doorbell for one of your neighbors - does your screen activate? (probably not). Can you active the screen yourself to see who's calling your neighbor? Both of these should help answer the question is "Does the coax still have a video signal even if the screen doesn't activate".

 

It may be that you can force the camera to activate by providing power to it directly etc but does the system broadcast the video signal through the whole building on the same coax or does it send the signal only to the phone that they called?

 

Check the +S "Privacy" connection.