Cable splitters and poe problems.

Toan the Moan

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Just testing an Ali express cable splitter using cat 5e cable T 568b configuration. The T is marked "IN", "OUT" yellow and "OUT" green. Into the router I have the y adapter with yellow and green RJ45 connectors. The issue I have is that the yellow on the Y splitter terminates on the T connector as the green and the Green of the Y router splitter terminates at the T splitter to the Yellow. I plugged in the cable splitters on the bench and discovered this issue of green is yellow and yellow is green but it connected ok. Here comes my mistake where it all went wrong

I plugged in a POE adapter to power the camera and the camera no longer works nor did it power up this was without the router being plugged in at this test stage.
From what my old brain can fathom out is that POE adaptors don't power the camera using the cable splitter but they do without the cable splitters.

The problem I now have is since connecting the splitters and POE adapters the camera cannot be found on my system anymore via my NVR or CMS on the pc.

The camera powers up fine if I connect it up without the cable splitters. I can only assume the splitter and poe adapters have sent 12 volts into the camera up the wrong wires. Can someone help me figure this nightmare out. If I have damaged one of the boards is it possible to replace it Pics attached TIA Screenshot_20201109-123436_AliExpress.jpgScreenshot_20201109-123415_AliExpress.jpgScreenshot_20201109-123453_AliExpress.jpg16049265116915670064244661847538.jpg16049265863837800266732697437868.jpg
 

tigerwillow1

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I'm not positive I'm understanding your setup correctly so ignore this if I'm wrong. I'm assuming you are powering the cameras using a POE injector as opposed to a POE switch. This splitter will not work with a POE injector. With possible rare exceptions, POE switches send the power and data to the camera using 4 of the 8 wires in the catx cable. This is what makes it possible to have two separate links on the same wire. When a POE injector is used, data is sent on 4 of the catx wires, and power on the other 4. There are no spare wires in the cable. The cameras accept either of the two power transmission methods, neither of which have anything to do with the camera's 12 volt power input option. POE injectors don't send 12 volts on the cable, it's nominal 48 volts.

If one of the cameras doesn't work because of damage, you could try powering it via its 12 volt input. The cameras generally run on 12 volts internally, and there have been reported cases of the 48-to-12 volt circuitry being fried while the camera still works when powered from its 12 volt input.
 

Toan the Moan

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Thankyou for the excellent informative reply. What I have is a non POE camera and was testing the 12v jack plug injectors with the ptz cameras own 12v power supply. This works fine until I tried to use the cable splitters. The camera didn't power up, so I thought no problem they aren't compatible I'll just forget the splitter idea and run a dedicated cat5e cable. However the problem now is the camera powers up does its boot sequence, but now no longer shows up on the router. I'm assuming that somewhere along the line the power injector plugs connected to the splitters have sent power into the data input outputs.
 
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tigerwillow1

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I'm assuming that somewhere along the line the power injector plugs connected to the splitters have sent power into the data input outputs.
That's a reasonable theory. The data lines are AC-coupled leading me to assume there's a transformer in the camera, which could have been fried by the injector power. I'm probably getting too deep into assumption territory here, My comment about the injectors sending 48 volts down the cable was based on the wrong assumption of a POE camera. In your case 12 volts is perfectly reasonable. A more complete explanation of the 4-wire vs. 8-wire methods is in a wikipedia article:

For 10BASE-T and 100BASE-TX, only two of the four signal pairs in typical Cat 5 cable are used. Alternative B separates the data and the power conductors, making troubleshooting easier. It also makes full use of all four twisted pairs in a typical Cat 5 cable. The positive voltage runs along pins 4 and 5, and the negative along pins 7 and 8.
Alternative A transports power on the same wires as data for 10 and 100 Mbit/s Ethernet variants.


Power over Ethernet - Wikipedia

I have a few runs with 2 cameras on the same cable using a splitter similar to what you bought, Some forum members frown on this, and I can only say it has worked flawlessly for me. This is with POE cameras on a POE switch.
 

Toan the Moan

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I assumed that the splitters being POE would allow me to use the 12volt injectors using the same wires this appears that that assumption was wrong, but I still cant understand why. The 12v injector at the router end appears to connect to cat5 cable sending power up to the power injector or receiver as I shall call it and 12 volts is at the Jack plug that connects to the camera.

At the rj45 socket in this adapter power receiver there is no connection between these power wires any more It appears that fitting the splitter has made a connection between the cat5e cable direct to the camera and power may have entered on the orange b type rj45. If that makes sense. I'm too old for this complexity
 

tigerwillow1

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PoE is not 12 volts. The standard is 48 volts.
I'm a card carrying member of the terminology police and this issue leaves me on both sides of the fence. Certainly the 802.3x specs require 48 volts nominal. But does a different voltage disqualify a link from being called POE? Regardless of that answer, it's in common use. Just search for 12 volt poe and see how many hits you get. If you want to get me going just misuse "ton". When somebody talks about a ton of people I divide 2,000 by what I consider an average weight to get the number of people. Or with a ton of money, I have to decide if it's referring to pennies, nickels, or whatever.
 

tigerwillow1

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Toan-Moan, after looking at your photos more closely I'm starting to doubt some of the conclusions I made. Without the ali express splitter in play, is this how your connection to a camera works?
PoeInjector.jpg

If that's the case, the Data In connector connects to pins 1,2,3,6 in the router/switch (green and orange pairs), and pins 4,5,7,8 (blue and brown pairs) are not connected to. The Power In connector connects to the blue and brown pairs, So in the long cable, the green and orange pairs carry the data from the router/switch, while the blue and brown pairs carry the power from the power adapter. At the camera end, the blue and brown pairs go to 12V Power Out, and the orange and green pairs go to Data Out.
 

sebastiantombs

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The standard for PoE is 48 volts is all that I was trying to point out to you. Non standard voltages are certainly used. I just didn't want you to wonder why a device that meets the 48 volt standard won't work with a proprietary 12 volt system or destroy a non standard device by plugging it into a source that actually meets the standard. If you want to yell terminology police, so be it. I won;t bother you anymore. Have fun :)
 

Toan the Moan

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Toan-Moan, after looking at your photos more closely I'm starting to doubt some of the conclusions I made. Without the ali express splitter in play, is this how your connection to a camera works?
View attachment 74524

If that's the case, the Data In connector connects to pins 1,2,3,6 in the router/switch (green and orange pairs), and pins 4,5,7,8 (blue and brown pairs) are not connected to. The Power In connector connects to the blue and brown pairs, So in the long cable, the green and orange pairs carry the data from the router/switch, while the blue and brown pairs carry the power from the power adapter. At the camera end, the blue and brown pairs go to 12V Power Out, and the orange and green pairs go to Data Out.
That's how it worked and a couple of others are wired like that that I have, that are 12v cameras not true poe cameras. The issue seems to have secured when using the cable splitters, a bench test seems to show that if I use the 12volt injector cables with the splitters, Orange and Orange white become positive and Green and Green white become Negative when pin checking the Green out of the splitter.

The "yellow out" doesn't become live. I haven't done a full pin out check just the 12 volt injector into rj45 splitter green and yellow out. This seems to prove that introducing the splitter has caused the 12 volts to be sent down the wrong wires and damaged the camera.

Just a reminder the camera does still powere up if wired normally just cant be found on the network
The splitter sent 12volts down the wrong cables it seems.
 
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alastairstevenson

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Just a reminder the camera does still powere up if wired normally just cant be found on the network
The splitter sent 12volts down the wrong cables it seems.
The ethernet signals are transferred in via an isolation transformer.
If indeed 12v has been applied between 1,2 and 3,6 then it's possible / likely that the ethernet transformer has been damaged.
If so - the camera will not appear on the network.
You may be able to see evidence of heat damage if you inspect the transformer.
It will be a plastic block about 12x8mm about 5mm height, 16 legs soldered down.
I don't see it on your camera image - it may be under the system board.

I've replaced several of these on cameras and NVRs - here is a damaged one from a DS-2CD2385G1 that I fixed up - you can see the fried windings on the first toroid.
 

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Toan the Moan

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The ethernet signals are transferred in via an isolation transformer.
If indeed 12v has been applied between 1,2 and 3,6 then it's possible / likely that the ethernet transformer has been damaged.
If so - the camera will not appear on the network.
You may be able to see evidence of heat damage if you inspect the transformer.
It will be a plastic block about 12x8mm about 5mm height, 16 legs soldered down.
I don't see it on your camera image - it may be under the system board.

I've replaced several of these on cameras and NVRs - here is a damaged one from a DS-2CD2385G1 that I fixed up - you can see the fried windings on the first toroid.
Pics of a couple of the boards one chip does look as though it's been a wee bit hot. If that is the chip I require is it available to buy here in the UK
 

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alastairstevenson

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one chip does look as though it's been a wee bit hot.
Yes, that's an ethernet transformer.
Is the surface of the plastic deformed? Or is that just glue residue from the sticker?

They are readily available on eBay and Aliexpress - but there are differing configurations to choose from.
The part number is obscured - is there any way you can expose it?
 

alastairstevenson

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It doesn't have to be the same part - just the same winding configuration.
It's pretty much a standard.

But - you need to be pretty sure it's been damaged before risking it's removal, it's a fiddly process.
 

Toan the Moan

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It doesn't have to be the same part - just the same winding configuration.
It's pretty much a standard.

But - you need to be pretty sure it's been damaged before risking it's removal, it's a fiddly process.
It smells burnt and had been very hot by the looks of it. I can only find them on ebay 5PCS X HB1601SNL SOP-16 GLORY | eBay

I have a good set of electronic soldering gear so should be ok with replacing it
 
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