#1
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Cctv dvr
Work upgraded their CCTV system a little over a year ago and the old DVR's were languishing under a table so we got told if anyone wanted them they were free.
Sold under a couple of names or no name at all with the model GLM-154 >>>SPECS<<< Basically it's a one-piece four channel DVR with a network interface, PTZ support and you can throw any hard drive in it and you don't lose the system OS or anything. Seems good enough but here is my problem. It didn't come with cameras. The four camera inputs are RJ45 ports. They look like ethernet but once you open the thing up you find they are NOT ETHERNET INTERFACES. Each port seems to pass through a tiny amount or discrete components before feeding into a fairly generic TW2804 quad input video chipset. Like, how I do I even wire this? Am I looking at some sort of coilless balun setup here or is there some established standard here I'm not aware of? The actual ethernet port has a lone Realtek chipset directly above it. |
#2
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I've seen ethernet baluns for the analog AV of security cameras...Perhaps that is what you need to feed it.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#3
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Just an update for closure I did some pin probing and managed to persuade out of it the following which is enough to make is useable:
Camera input port (RJ45 modular) 1 - ? 2 - ? 3 - DC +12v 4 - Audio in 5 - GND 6 - GND 7 - Video in 8 - ? I can clearly see a few volts running on pins 1 and 2 but pin 8 remains a mystery. I was able to track down the manual but it's an EXTREME case of Chinglish and remains really vague on the camera inputs. Basically the manual states that you can record andio and video from a camera which clearly I've probed out but that is it. Things like relay I/O, alarm inputs and RS485 have their own and much more cleanly marked ports. Perhaps there's additional "features" in the ports. |
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