Introduction
This section gives some basic info on how PoE works. PoE stands for Power Over Ethernet and knowledge of PoE standards may be beneficial to some installers in some cases.
Note that more thorough PoE guides are available on the internet.
This section is provided 'as is' and no official support is intended or implied.
Other Online Sources
The following links are to external websites. Irisys is not responsible for content on other sites
https://en.wikipedia.org/wiki/Power_over_Ethernet
What is PoE?
Power over Ethernet, or PoE, describes any of several standard or ad-hoc systems which pass electric power along with data on twisted pair Ethernet cabling. This allows a single cable to provide both data connection and electric power to devices such as wireless access points, IP cameras, and VoIP phones.
There are several common techniques for transmitting power over Ethernet cabling. Three of them have been standardized by IEEE 802.3 since 2003. These standards are known as Alternative A, Alternative B, and 4PPoE. For 10BASE-T and 100BASE-TX, only two of the four signal pairs in typical Cat 5 cable are used and Alternative A transports power on the same wires as data for 10 and 100 Mbit/s Ethernet variants. Power is transmitted on the data conductors by applying a common voltage to each pair. Because twisted-pair Ethernet uses differential signaling, this does not interfere with data transmission. The common-mode voltage is easily extracted using the centre tap of the standard Ethernet pulse transformer.
Alternative B separates the data and the power conductors, making troubleshooting easier. It also makes full use of all four twisted pairs in a typical Cat 5 cable.
For Gigabit Ethernet and faster, all four pairs are used for data transmission, so both Alternatives A and B transport power on wire pairs also used for data.
4PPoE provides power using all four pairs of a twisted-pair cable. This enables higher power for applications like PTZ cameras, high-performance wireless access points, or even charging laptop batteries.
In addition to standardizing existing practice for spare-pair (Alternative B), common-mode data pair power (Alternative A) and 4-pair transmission (4PPoE), the IEEE PoE standards provide for signaling between the power sourcing equipment (PSE) and powered device (PD). This signaling allows the presence of a conformant device to be detected by the power source and allows the device and source to negotiate the amount of power required or available.
In general, when discussing PoE, it is this IEEE standard that is being referred to and because of this, essentially, PoE is not just a 48V power supply.
PoE Compliant Devices
Being PoE complaint means that a device conforms to the official IEEE 802.3af PoE standard.
A PoE switch must include the sensing electronics at each powered port in order to detect when a PoE capable device is connected. Power must be disabled by default, and only when a PoE switch recognises a PoE compliant device has been connected should power be enabled. This ensures that a non-PoE device will not be destroyed when connected to a PoE switch, and prevents power reaching a PoE device when wiring errors are present.
Vector PoE vs Vector non-PoE
Vectors are available in both PoE and non-PoE versions. Most Vectors sold today are PoE capable, but non-PoE devices area still available for specific cases.
f your Vector has a green power connector then it is not PoE compliant. All initial devices will have a green power connector, and so cannot be powered using PoE.
If such devices are connected to a PoE switch or other device that conforms to the PoE 802.3af standard, no damage will occur, it will simply not power on. But be aware of ‘dumb’ power injectors as these will blindly send 48V into the Vector which will damage it.
Vectors with no green power connector are PoE capable.
Specific Part Numbers are shown here:
| IRC6637-AW (IRC6637-AB) | Vector Analytic White (Black) | Yes |
|---|---|---|
| IRC6637CAW (IRC6637CAB) | Vector Count White (Black) | Yes |
| IRC6637SAW (IRC6637SAB) | SafeCount Vector Primary White (Black) | Yes |
| IRC6637SNW (IRC6637SNB) | SafeCount Vector Secondary White (Black) | Yes |
| IRC6637-SW | Vector Analytic Non-PoE White | NO |
| IRC6637SSW | SafeCount Vector Non-PoE White | NO |
| Description | PoE Enabled |
Non-Compliant ‘Dumb’ Power Injectors
Switches and ‘power injectors’ that are not PoE compliant do not have the detection electronics required by the standard, and power from these devices is always on. Because of this, always be cautious when using unknown power injectors or switches.
If you still intend to use a cheap 'dumb' power injector to power your PoE Vector, always fully test the connecting cable at time of installation for any incorrect wiring or damage as this could send power to the wrong pins of the Vector and permanently damage it. Note that damage of this type is not covered by warranty.
Irisys Counter Power Precautions
Powering a Vector incorrectly can permanently damage it. Such damage is not repairable nor is it covered by warranty, so being aware of the possible issues could negate a costly device replacement.
PoE enabled Vectors are fully compliant with the 802.3af PoE standard. This means that when connected to a PoE switch, the switch will recognise it as such and then enable power to it.