No, it is not safe to plug an ordinary PC into a passively-powered 24V PoE switch output. Unlike standard 48V "active" PoE - i.e. 802.3af/at/bt - which checks whether the connected device needs to be powered, the "passive" PoE provided by 24V switches is always on if the port is configured to send power.
The maximum transmission distance of copper UTP cable is 100 meters (328 feet). The challenge is installing Powered Devices (PD) like PoE IP cameras more than 100 meters from the Power Sourcing Equipment (PSE). Using midspan power injectors along the copper cable between network equipment does not extend this distance.
[A] Yes. Power over Ethernet is a developing technology whereby supply voltage is provided to certain types of devices through the same cable that is providing the data signal, such as CAT 5 Cable. These type of devices are called "PoE Compatible" (or "Active Ethernet Compatible").
Can it damage my equipment? IEEE 802.3af/at/bt compliant PoE technology is safe. PoE injectors and switches will not damage any equipment, even if the equipment is not designed for PoE applications. This procedure uses low voltage and is harmless to any connected device, PoE or non-PoE.
Maintain the current 802.3af output voltage specification of 44Vdc to 57Vdc for PoE Plus. Specifying the output voltage to have a range between 44 Vdc and 57 Vdc will allow the PSE to incorporate a 48 volt battery pack and provide integrated battery backup.
Because CAT6 cables perform up to 250 MHz which is more than twice that of CAT5e cables (100 Mhz), they offer speeds up to 10GBASE-T or 10-Gigabit Ethernet, whereas CAT5e cables can support up to 1GBASE-T or 1-Gigabit Ethernet.
Ethernet and POE both restrict cable distances to 100 metres (328 feet) between network ports. However, POE-powered devices such as IP cameras and wireless access points frequently must be located at far greater distances from the nearest network switch or power outlet.
A PoE extender is a device used to extend Ethernet network devices beyond the basic 100m distance limit for twisted pair Ethernet cable.
A WiFi connection transmits data via wireless signals, while an Ethernet connection transmits data over cable. An Ethernet connection is generally faster than a WiFi connection and provides greater reliability and security.
For all practical purposes, there will be no effect on the speed of your connection. There will be a very insignificant amount of delay due to long cables. Given that the maximum length of cable you can run (per the Ethernet spec) is 300 ft, the cable length could never cause more than 300 ns of delay due to the cable!
Coaxial cable can be cabled over longer distances than twisted-pair cable. For example, Ethernet can run approximately 100 meters (328 feet) using twisted-pair cabling. Using coaxial cable increases this distance to 500m (1640.4 feet).
If there is an existing twisted-pair copper or coax cable run, then you can extend your network with a pair of Ethernet extenders. Use one at each end to convert Ethernet to DSL (digital subscriber line) and back again to Ethernet. Extenders can deliver 50-Mbps speeds over 300 meters or about 10-Mbps at 1400 meters.
Cat 8, the next generation of Ethernet cables, is on the horizon but for the time being, Cat 7a (Cat 7 “augmented”) is the highest-performing Ethernet cord available. Like the Cat 6a and Cat 7 cables, the Cat 7a supports speeds up to 10,000 Mbps, but the max bandwidth is much higher at 1,000 MHz.
The length is exactly 100 metres as (doing the maths) anything over 100m will be long enough for an ethernet device to transmit a frame and not hear the collission detect back-ff from the far end. so anything over 100m will be subject to late-collisions.
The main advantage of Power over Ethernet (PoE) is delivery of data AND power over one Cat5e/Cat6 Ethernet cable. PoE ends the need for AC/DC power supplies and outlets. A remote installation costs less than fiber as no electrician is required. Ethernet cable costs less and is often already installed buildings.
Ethernet cables generally carry a very small amount of electricity at high frequencies for the purpose of sending data. However Ethernet cables can also be made to carry significant power for use of device connected to the cables. The trick to making this work is that for data purposes their are 4 pairs of wires.
CAT6A – The Solid Choice for PoE
- Solid copper wire delivers higher performance than alternatives.
- Capable of transmitting 10-Gigabit Ethernet over a distance of 100 meters.
- Offers transmission bandwidth frequency of 500 MHz.
- Improved alien crosstalk characteristics due to insulation and additional, tighter twisting.
Category 5e and Category 6 cable can be used to support PoE devices, but the consensus is clear: You're better off using Category 6A for a number of reasons we're going to cover here.
Power over Ethernet (POE) is a technology that lets network cables carry electrical power. However, if the camera is POE-enabled, only the network connection needs to be made, as it will receive its electrical power from this cable as well.
If your PoE device uses the PoE standard 48V 802.3af or 802.3at, it is considered to use active POE. Passive PoE usually refers to any device using PoE that is not 802.3af or 802.3at. This includes devices such as cameras and radio antennas that run on 24V PoE.
Power is supplied as a common-mode signal over two or more of the differential pairs of wires found in the Ethernet cables and comes from a power supply within a PoE-enabled networking device such as an Ethernet switch or can be injected into a cable run with a midspan power supply.
CAT 7 cable, whilst being the more expensive option, is also considered the most durable, and has a longer lifespan than CAT 5 and CAT 6, improving its overall return on investment, and is the best choice for wiring with the future in mind.
While delay in general may be a factor of the overall cable construction, delay skew is primarly caused by the overall inconsistent pair geometry and twist rates. For example, extreme differences in twist rates from pair to pair can cause a higher delay skew.
