Dahua 2MP 25x Starlight IR PTZ Network Camera (SD49225T-HN)

mpbcam said:
... now I'm curious and will have to check it out.
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Yeah, according to the specs, it's supposed to work like this (quoted from POE Explained - Understanding and using Power over Ethernet):
The final stage after detection and classification of a newly connected device is to enable power: the 48V supply is connected to the cable by the PSE so the PD can operate. Once enabled, the PSE continues to monitor how much electrical current it is delivering to the PD, and will cut the power to the cable if too much, or not enough, power is drawn. This protects the PSE against overload, and ensures that POE is disconnected from the cable if the PD is unplugged.
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My guess (and just a guess, based on the outcome) is the PoE injector in question didn't do that and it started lowering the 48V as a result of the increased demand. I suppose it would matter if the heater was inductive or resistive... based on what happened I'd assume it was inductive (heater coils).
 
So using this is actually dangerous, or only of you plug POE+ into it? WS-POE-8-48v60w Passive 10/100 Power over Ethernet PoE Injector for 8 IP Cameras, VOIP Phones or Access Points, 48 volts, 60 Watts Total Power

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yes, those passive devices are very dangerous.. plug a non PoE device into it and its still gonna get power and likely nuke the network interface.. if your lucky.

there's no negotation going on w/passive PoE, whereas Active PoE is safe for non-poe devices as they wont perform the handshake to enable power delivery.
 
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nayr said:
yes, those passive devices are very dangerous.. plug a non PoE device into it and its still gonna get power and likely nuke the network interface.. if your lucky.

there's no negotation going on w/passive PoE, whereas Active PoE is safe for non-poe devices as they wont perform the handshake to enable power delivery.
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Better order that Poe midspan soon then lol
 
hmjgriffon said:
Yes, I used one of those little WS whatever injectors, camera ran fine for like a week, I played with everything even cranking the IR up all the way and never any issues so I'm still suspect on the heater thing but it died from something.

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No problem, we get them back and ask dahua to fix it. So all guys be careful for the power supply for the cams
 
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Does a single cat 5 cable running to this camera (or any ptz) from a Poe switch or Poe capable nvr power the camera?

Or do you need an additional power supply?
 
It's currently 38c here and the cameras OSD is showing 56c. How's everyone elses doing?
 
I ususally see about +20C over ambient always on my Black Face PTZ, thats not air temp.. thats cpu temp
 
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47F out, 84F Camera. 30x hni though..
 
In the installation guide, to reset the camera or add an SD card it says open the rear cover. To open the rear cover do you remove these screws? Thanks.
 

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It does have a little bit of blue locktite on the threads, but it should remove easy enough. If you do get it open watch out for the gasket in there, mine seemed a little too large for the groove it was sitting in, had to make sure it was in as best it could. I did have a few rounded screws on mine, I think someone was a bit over zealous during assembly.
 

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