2. How does PoE compare to Powerline Networking?
2. Powerline networking is considerably slower and less reliable than CAT5/6. Additionally, building code for running power lines is much more strict than low voltage CAT5/6
Reolink cameras are pretty good for what they are. Just dont buy into their NVR solution...
Frigate also has some interesting applications to go along with it, see: https://github.com/mmcc-xx/WhosAtMyFeeder
I also have YOLO on my to do list for the home cameras.
I put them on separate vlan where they get no outbound network connectivity.
For cases where you want things like facial detection or license plate detection (automatic doors/gates) get a Unifi AI though and those things cost, but for normal perimeter/room monitoring the cheap ones are very good
Do you buy Ethernet cables of different colors and say "Yellow is reserved for PoE, all yellow cables should be assumed to have power on them"? Or do you slap a "48V" label on both ends of the cables you're going to use for PoE and the label is what warns you that this cable should only go into the PoE receiver, and not into an unpowered device? Or do you just not label your PoE cables any differently, and trust that the injector will never malfunction at the same time that you plug the PoE cable into the wrong device?
The data travels as the differential voltage in each of the twisted pairs, and is transmitted magnetically by the transformer to the secondary winding. The power is applied between different pairs, and in each pair appears as a common mode voltage. This is all stopped by the transformer, and in devices designed to support PoE, the PoE circuits tap the mid-point of the primary windings to access the supplied voltage.
So at a first glance, it seems that if 48 volts is applied between the twisted pairs to a non-PoE device, this voltage would simply be blocked by the transformer. But since there is a widespread concern about this, there must be more to the story -- maybe somebody who actually worked with these circuits can explain why this is more complicated than it seems at first?
Edit: Found an answer. It seems that at least some of the designs of non-PoE Ethernet jacks terminate the common mode signals to a common ground though 75 Ohm resistors. In this case, if the voltage were applied between the twisted pairs, the resistors would dissipate far too much power and would burn out. So there is definitely a concern with the dumb PoE injectors and at least some non-PoE devices. https://electronics.stackexchange.com/questions/459169/how-c...
Whenever possible, I opt for PoE. It’s a damn shame it’s limited to a niche userbase given its myriad advantages.
What does enterprise grade mean to you?
Mikrotik website has a good selection of them and if you look at the other hardware types it'll be interesting in getting an idea of weird things you don't see in normal offices.
https://mikrotik.com/products/group/switches
Apart from obviously larger bandwidth options like 28qfsp 100gb (I'm unaware if mikrotik does them but 400gb is normal in some circles) there's things like reverse POE switches, media converter switches, and all sfp+ switches.
Poe++ exists and you can use switches with it to power poe+ switches that will power poe switches. Or they can be used to power laptops or NUCS directly.
For those thinking about adding one they've grabbed off amazon and installing themselves, please do a bit of hunting and reading rather than just buying the first word soup brand cheapest ones. Also remember installing uncertified electronics in your walls is a good way to void your insurance if they're the cause of disaster and turn it into a legal battle even if they're not.
Can you expand on "often, but not always, power"? Here's my guess:
* It's more efficient for the small stuff: little wall warts aren't very efficient I think in part because there's some no-load consumption for each. The switch pays that no-load cost once for many devices and has like an 80-plus gold or better PSU, hopefully. And then I think even cheap buck converters are like 95% efficient; they have some no-load consumption too but I think less than the wall warts? And even though this goes over 2 (or 4) tiny wires, at 48V–56V, the current is low enough that power loss is not bad because those wires are just for one small device, and P=I^2R.
* It's less efficient for the big stuff: that P=I^2R starts to suck for the PoE case, and in the non-PoE case they're more likely to have efficient AC->DC conversion on their own. 90% efficient beats 90% * 95% efficient.
Where ever you're putting the TV you have to put in regular power anyways, so it's fairly tidy to just put the device's power cable parallel with the TV's power cable. WiFi will handle communication. On the other hand, NEC and CEC requires minimum of 2 inches gap for communication wiring to electrical so you're now you've got that minor complication.
POE makes sense mostly when it makes sense to combine communication and power cabling. Corded phones, wifi access points, security cameras, small touch screen modules, etc. Not saying what you're doing can't work, but the added expense of installing parallel CAT6 everywhere doesn't seem worth it.
I ended up buying a PoE extractor and barrel plug adapter for my Roku, and another extractor for my HDHomeRun.
It annoyed the heck out of me that they had PoE running to them and still had to be plugged into a separate transformer.
PoE (Power over Ethernet) sends both DC power and data through the same twisted-pair Ethernet cable, allowing devices like IP cameras, wireless access points, and VoIP phones to run without separate power lines. The power is delivered by Power Sourcing Equipment (PSE) — either an endspan (built-in PoE switch) or a midspan (PoE injector placed between a non-PoE switch and the device). The powered device (PD) negotiates power via detection and classification before voltage is applied, preventing damage to non-PoE gear. IEEE 802.3af (Type 1) provides up to 15.4 W at the source, 802.3at/PoE+ (Type 2) up to 25.5 W delivered, and 802.3bt (Type 3/4) extends that to roughly 60–90 W using all four wire pairs. Engineers need to understand not just wiring, but also cable category limits, pair usage, power losses over distance, and heat dissipation — especially at higher power levels. Modern PoE designs must consider standards compliance, thermal management, and efficiency, as power density rises with new generations of PoE technology.
- PoE endpoints should have isolation barriers, factor this into cost and size estimates
- Don't skimp on TVS
- ideal diode full bridge rectifiers are really cool and you should use them (in more power entries than just PoE)
- Was having a conversation today about isolation and grounding for POE (product has a metal case). Do you have a reference? Or standard?
- TVS ahead of the bridge right?
- Do you have a part recommendation or reference design for ideal diode POE?
I have a Ring home security system. I would like to get an offline home CCTV that only records when the alarm is set (either in Home or Away).
A quick internet search does not show an API. I'm not sure Ring has a device that I could wire a relay (if that's the right thing) to.
cyberax•4h ago
VanTheBrand•3h ago
So any 10GbE (and 2.5GbE) PoE/PoE+ devices out there are technically not to spec (lots of these on Ali Express) but I believe the the Ubiquiti 10GbE stuff is all at least PoE++. [1]
(They do have their own non spec labeled PoE+++ products though, which are really just “802.3bt Type 4” but they added another plus because that probably sounded better.) [2]
[1] https://store.ui.com/us/en/products/us-xg-6poe, https://store.ui.com/us/en/category/accessories-poe-power/co...
[2] https://store.ui.com/us/en/category/accessories-poe-power/co... , https://help.ui.com/hc/en-us/articles/115000263008-PoE-Avail...
zamadatix•3h ago
As a result, it tends to be relegated to the "high end switch which has every feature those one-off customers demand but costs an arm and a leg as a result" model/family. E.g. the only ones I ever sold were to a hospital that wanted to have select switches have 10G for radiology workstations but also wanted to still be able to plug 1G APs in without having to think about the port types. Radiology was covering the cost, so they didn't care it was a waste of money.
VanTheBrand•2h ago
zer00eyz•2h ago
wmf•2h ago
zer00eyz•1h ago
mrheosuper•2h ago
fc417fc802•1h ago
MBCook•1h ago
The new 14” MacBook Pro comes with a 70 watt charger. An M4 Air only gets a 35 watt adapter.
Basically seems like enough power is available to run something pretty powerful.
cyberax•1h ago
I have not yet tested WiFi 7 APs, but they are supposed to be even faster. The use-case for me is video editing over WiFi (I do have a 10GBe Thunderbolt adapter but hey, I like wireless).