POE IP camera non compliant with 802.3af ... Looking for cable

[nebv]

Hello,

I buyed several 2M POE IP cams from Dongjia incl. a 8 Port POE NVR Type 2508. As I tested them, I found that the
NVR (with 2 NICs) is not very flexible in the configuration. That means that the forwarding between the 2 NICs is not active
and I cant see the cams behind the NVR from the LAN. The CAMs cannot synchronize the time/date with NTP servers from internet and I want to reconfigurate them any time if necessary without changing IPs.

I decided to use a POE switch connected on just one of the NICs from NVR. The problem is that the cams
are not working (they become no power from switch). I found that the switch is working in mode B (the switch is a high quality, industrial one, 3810G from Korenix) and the cams are working only in mode A.

As I read the standard 802.3af I found that the PSE (the switch) can work in mode A or B (just one of them) but the
PD (powered device, like the cam) must support both modes. If not the PD is not 802.3af compliant...that seems to be with my cams

I opened one cam and found that the RJ-45 is only a 4-wire cable. For mode A is enough. For mode B isn't because the
power supply is coming on 4/5 and 7/8. I found in the cam a small connector which is not wired and is marked with
4/5 7/8...the IC on the POE Board is an AS1138 and I found that this IC is full compliant with 802.3af

The question now is, at first if I may electrically connect the 4/5 and 7/8 from the POE switch to this connector
and the 2nd where could I find such cables or the components like the small connectors to build it.

An answer from you would be very appreciated.
Many thx
Ciprian

 

[nayr]

1. no, you'll be doing bad things like sending power back to the switch on a pair its not expecting.. or trashing the ethernet signals, or messing up polairity and making something go poof.. it could be done theroetically with some diodes and enough work but I would not even bother, see #2
2. use these and be happy: http://www.amazon.com/ELEGIANT-Ethernet-Splitter-Adapter-Cameras/dp/B0146LFMZG

 

[SquareEyes]

As above but these are much cheaper and smaller, plus you get 2 for the price of one if you can change a female to male 2.1mm jack.

The small size and price are the only distinguishing features.

 

[nebv]

Hello and thx for your answer ... but I can't be happy with two power injectors one outside and one inside... each of them has a 80-85%
efficiency ... by 8 cams with 12Watt means 32Watt per hour for nothing.

I suppose that the POE Module inside the cam was well done for full 802.3af compliance but
was castrated with the "only mode A" cable because of missing wires.
Pls take a look to http://www.alibaba.com/product-detail/12V-1A-PoE-PD-module-for_60378911899.html
My POE module has the same connectors. On connector J3 pin 3/4 is "expecting" POE from Switch. from 4/5 and 7/8.. and here is no cable connected from the suplier.
I see no collision here at least. These pins are connected to 4 diodes already on the POE board for injecting with right polarity

Maybe was this an issue for somebody else who already solve it... I would also risk and try ... but I don't know where could I find such cables
with such small connectors

THX
Best regards
Ciprian

 

[nebv]

the grid dimensions are 0.05 inch (1,27mm)

 

[SquareEyes]

Hello and thx for your answer ... but I can't be happy with two power injectors one outside and one inside...

Correct me if I am wrong, but the above proposed solutions only require a camera end PoE splitter, provided that they are connected to a PoE switch/NVR?

 

[nebv]

Hi SquareEyes,

the IP Cam has already a POE Module inside. The issue was (I will explain in a few seconds why) that the IP Cam (PD=powered device) is working only with a PSE (power source equipment = POE switch) which is working in mode A (wired Pins only 1236)

If you have one with mode B like Korenix 3810G (a very very good industrial switch which is working between -25°C and 60°C and 1GByte uplinks) the cam will stop to work, because in mode B the PD will be powered on pins 4/5(+) and 7/8(-) and NOT on 1236

The IEEE 802.3af site 49 says that a PD MUST WORK IN BOTH MODES. THE PSE can deliver mode A or B here are no constrains.

If not is not a 802.3af compatible device. And that was my problem Dongjia CAMs are not compliant because are working only in mode A.

As the support from Dongjia is not a real tehnical one, I opened the case, found an unwired pitch connector with 4/5 7/8, check the POE Board for the ICs and their compatibility.... and few minutes ago I risked and wired these pins with 4/5 7/8 from Korenix mode B and IS WORKING like a charm.
And is working also in mode A with a MOXA P308 (also an industrial Switch)...

I hope that Dongjia will sent me compatible cables ... if not I have to make them myself ... now I have two wires soldered on the POE module.. is OK but only for testing.

I hope you understand me ... I just wanted to solve this issue with the internal POE module/cable and not to add a new POE injector
and have additional power loss and some additional things behind the cam.

Best regards
Ciprian

 

[bp2008]

Correct me if I am wrong, but the above proposed solutions only require a camera end PoE splitter, provided that they are connected to a PoE switch/NVR?

I think he is talking about having to convert his incoming AC power to 48v DC at the PoE injector/switch and then from 48v DC to 12v DC at the camera with the added dongle. Each conversion has some loss. It is likely not much better using passive PoE splitters (which skip the 48 volt step and require 12 volt power supplies) because of the inefficiency of pushing 12v down ethernet wire.

 

[Stealth22]

@bp2008 or @nayr, just to clarify, the Hikvision cams from Nelly's are 802.3af compliant, correct?

The spec sheets seem to suggest that they are...I just want to make sure that the PoE switch I'm planning to buy has enough power. It has 8 PoE-enabled ports, and a total power budget of 85W. It provides a max of 15W per port, but it can't do that for all 8 ports at once.

Just want to make sure that the cameras and/or the switch will be smart enough to know that the cams only need 5~7W of power each. I don't want to spend money on that switch, only to have it not work.

(I'm in IT, but I'm not a network engineer, so my knowledge of PoE is pretty limited)

 

[nayr]

the one squareeyes posted is not PoE, ignore that.. its just a dumb injector

the one I posted is compliant PoE, will work with a standards compliant PoE switch and will output 12VDC that you can use to power your camera...

I know that your camera is not operating off 48VDC, its being dropped down to 12VDC and thats being dropped down to 3.3VDC.. internally its 3.3V I guarantee and its been converted many times already.. so if you give it 12VDC your not changing efficiency one iota.

 

[nebv]

@bp2008 or @nayr, just to clarify, the Hikvision cams from Nelly's are 802.3af compliant, correct?

The spec sheets seem to suggest that they are...I just want to make sure that the PoE switch I'm planning to buy has enough power. It has 8 PoE-enabled ports, and a total power budget of 85W. It provides a max of 15W per port, but it can't do that for all 8 ports at once.

Just want to make sure that the cameras and/or the switch will be smart enough to know that the cams only need 5~7W of power each. I don't want to spend money on that switch, only to have it not work.

(I'm in IT, but I'm not a network engineer, so my knowledge of PoE is pretty limited)

My cams are also POE 802.3af compliant but only on the paper because doesn't respect the standard (only the half of it, not full)
The right power budget of the switch is not all what you need ... if the HKs have the same problem as these from Dongjia respectively they work only with a POE switch in mode A and you have a switch in mode B
then you will have the same issue as I had.

you can read here about this standard
http://www.lan-power.com/pdf/802.3af-2003.pdf

 

[bp2008]

All I can say is I have used Hikvision and Dahua cams with several different PoE switches and injectors and never had a problem. The cams are supposed to be 802.3af compliant and I have never had reason to doubt it.

 

[nayr]

@Stealth, yeah the Hikvision ones are compliant and will take power over whatever pair is provided.. the only PoE Standards they wont work with is Cisco-Legacy, and thats a pre-spec thats pretty hard to find now days.. the polarity is wrong for those.. Ive never heard of anyone having compatibility issues due to compliance.

The problem with the Dongjia's are they dont have enough wires to support both Mode A&B, and that's required to call your self PoE Compliant.. so the manufacturer has lied, I would not give them anymore business personally.

If Hiks and Dahuas had been lying about PoE compatibility we'd surely know by now.. Mode B is the most common for GigE switches, and for just about all switches that I know of, since it completely avoids using a data pair for power.. and instead uses a pair thats normally floating on all but PoE devices.

 

[Stealth22]

@Stealth, yeah the Hikvision ones are compliant and will take power over whatever pair is provided.. the only PoE Standards they wont work with is Cisco-Legacy, and thats a pre-spec thats pretty hard to find now days.. the polarity is wrong for those.. Ive never heard of anyone having compatibility issues due to compliance.

The problem with the Dongjia's are they dont have enough wires to support both Mode A&B, and that's required to call your self PoE Compliant.. so the manufacturer has lied, I would not give them anymore business personally.

If Hiks and Dahuas had been lying about PoE compatibility we'd surely know by now.. Mode B is the most common for GigE switches, and for just about all switches that I know of, since it completely avoids using a data pair for power.. and instead uses a pair thats normally floating on all but PoE devices.

Ok, great, that helps a lot.

So I should be good as far as the power consumption goes? The switch is the JGS516PE by NetGear.

 

[nayr]

as long as your cameras dont add up to more than it can output, just think of it as an 85w 48VDC power supply, because thats fundamentally all it is.

 

[nebv]

@nayr

small question regarding 9xPOE NVR 2508 from dongjia but even from other suplier .... the NVR has 8 POE 100MBit Ports in one Network segment (NIC1) and 1 GBit Port (NIC2) on another network segment.
I tried one or two days several things like forwarding activating, static rules on the router ...and so on.. wihout success.
I can't access the cams behind the NVR from the LAN. That is quite important at the begining if you want to change some parameters from the cams and you are working only from the LAN segment.
Even the cams cannot ask the NTP Servers from internet for setting the time / date. As I used 1 POE-Port from NVR and made an Uplink to an additional POE switch (it was a GBit Port from a Cisco) all POE Ports from the NVR were go down to 10Mbit ... very mistic here.
The only way to get this NVR running in a flexible way was through using another POE switch with 1xGBit uplink to NVR-NIC2 and 1GBit uplink to the Router (Gateway to the Internet).
The NVR is running this way very good, is very stable, fast (Hi3535)... but I forgot the POE Ports from the NVR.

I read that other NVR suplier have also no forwarding activated. Maybe some news here?

THX

 

[nayr]

thats standard procedure, they are isolating the cameras on there own network.. they dont need access to NTP servers as your NVR should be providing timesyncing.

if your wanting more network flexibility, then dont get a built in PoE switch.. but if your wanting simpler security, ala Closed Circuit TV, then you get a good enough NVR and Camera combination that you can configure your cameras via your NVR and there is no reason to connect directly to any of em.. or deal with having to bypass all the security to reconfigure every once and a while.

 

[nebv]

the problem is that I cant configure the cams through the NVR... NVR takes the parameters from cam and is working with...for example bandwith ... I can put AND SAVE )) another value on the NVR but as soon I refresh will come the old setting again from cam. Only if I change it directly on cam will be taked over to NVR ... the same with other parameters.. And regarding NTP I didn't see where could i set the NVR as a NTP server.

 

[nayr]

it dont use NTP, it uses Onvif to set the time more than likely.. attached is the option on my dahua nvr.

sounds like an issue with your NVR, cant help you there.. most of the cheaper/dumber ones are just really basic and anything beyond that is kinda flakey at best.. you cant bridge that network with your main netork without creating issues since they are seperate networks.. you'd need a vlan capable switch to extend those ports and a router to make that network reachable from another subnet.

 

[nebv]

nice and logical ... HDD full >>> overwrite ... By Dongjia HDD full is "exception" I supose I have to format the disk when is going full ... in one week i will see :-(