You may have noticed that some HDMI extenders are tagged with “PoE“ or “PoH”. They are short for Power over Ethernet and Power over HDBaseT accordingly. They both enable electric power along with data to be transferred from one end to another via one single Ethernet cable.

PoE (Power Over Ethernet)

PoE is a technology that enables Ethernet cables to pass electric power along with data to the connected device.

PoE in the ProAV

The transmitter and receiver of an HDMI extender over CAT are connected via an Ethernet cable. If the HDMI extender supports PoE (or PoH), the powered box will keep the other box charged via the Ethernet cable as electric power is transferred along with the data.

Note: When connecting a KVM extender, having the power adapted and connected to the receiver end (where the USB hub rests) may help solve the trouble of peripherals not working well due to the power voltage.

PoE is also used beyond ProAV products and other electronic devices. For example, a surveillance camera is installed outdoors and it’s always connected to an NVR system or a monitor for monitoring and management. With the tech of PoE, the camera will get a power supply through the data cable. In this case, no extra power socket is needed and the installation would be more flexible and stable.

How Does PoE Work?

A CAT cable consists of four twisted pairs of cables, and PoE sends power to PoE-enabled devices via these pairs. At first, PoE sends power over via two of these twisted pairs and the other two are used for data transmission. In its later version, power and data are both delivered across all four twisted pairs under the new PoE standards.

Because electricity power and data are transported at two ends of the frequency spectrum (the form at a low frequency of less than 60Hz, the latter at a high frequency of more than 10 million), they are not interfering with each other and both of them can be well transported to the other side through all the four twisted pairs of the cable.

PoE Applications and Its Benefits

The importance of PoE was immediately recognized. Transporting both power and data over a single cable not only reduced cabling requirements but also improved safety and simplified installation, saving time and money. PoE’s value exacerbated the need for greater power to accommodate a broader range of end devices, resulting in various additions and upgrades.

Using one set of Ethernet cables for both data and data transportation, PoE is useful for video surveillance, retail video kiosks, smart signage, vending machines, and other retail appliances.

PoE has many benefits for the installation.

  • Economic — Electrical power cabling is not necessary. Fewer cables are required. And the time of troubleshooting the power cabling and electricity supply is saved. PoE makes installation easier and brings down the total cost.
  • Flexible — A nearby electrical outlet is no longer a must. Devices such as KVM Extenders can be installed wherever they are needed most, and they can be moved around easily without causing any power cut out.
  • Safe — PoE includes a built-in safety mechanism. For example, when the connection is interrupted, the PSE automatically stops delivering power and begins a handshaking procedure before transferring power again. That is, if a cable sustains damage, power will be cut off.

PoH (Power Over HDBaseT)

Power over HDBaseT enables the transmission of DC power in conjunction with data signals over a single Ethernet cable to a distance of up to 100 meters/328 feet (the length an HDBaseT extender could run).

One key difference compared to PoE is that instead of the powered device assuming worst-case cabling, PoH allows the device itself to identify the cable length and draw more power as long as it does not exceed 100W (the limit of HDBaseT technology).

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Conclusions

PoE and PoH are useful for installation, especially installation projects of a great number of appliances in places where electrical power outlets are limited. Moreover, the convenience it brings with stability or for later adjustment makes the technology valuable as well.

AV Access is an experienced, professional ProAV & IPAV manufacturer and we offer quality KVM extenders, HDMI extenders, AV over IP solutions, and more. Visit the AV Access shop to pick an HDBaseT extender today! If you have any questions please feel free to contact us at info@avaccess.com. We have you covered.

Source: https://www.avaccess.com/blogs/guides/poe-power-over-ethernet/