Manual:PoE-Out

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Summary

this page describes how poe-out feature can be used on RB750UP and OmniTik UPA-5HnD. These routers provided power only over the spare pairs.

This feature will become available on new device featuring SwOS interface that will also provide power only over spare pairs. It will use new PoE-out controller firmware.

Configuration

RouterOS

PoE Out can be configured in /interface ethernet menu and each port can be controlled independently.

Power on 100MBps interface is provided over spare pairs (blue and brown) where blue pair carries positive and brown - negative.


Configuration options are:

  • auto-on - board will attempt to detect if power can be applied on the port. For power-on to happen there should be resistance on spare pairs in range from 3kΩ to 26.5kΩ. It is the default setting;
  • forced-on - detection range is removed. As a result power over Ethernet will be always on;
  • off - all detection and power is turned off for this port.

SwOS

PoE Out feature configuration will be available from SwOS Link page where one of PoE Out profiles can be for each PoE Out enabled port individually:

  • auto - detection is done regarding resistance on the spare pairs to check if port has PoE capability. For port to be turned on measured value should be within range from 3kΩ to 26.5kΩ;
  • on - PoE Out is enabled on the port regardless of the resistance on the port. Use this with caution as that can damage connected equipment;
  • off - PoE Out is turned off.

Monitoring

New PoE Out controller firmware enables monitoring of the PoE Out state

RouterOS

It is possible to monitor current usage on interfaces via poe-out-current attribute value. 

/interface ethernet monitor ether3

Or in winbox Interface -> open 'interface details -> Status tab.

will show current usage on the port 


[admin@MikroTik] > interface ethernet monitor ether3,ether4 
             status: link-ok no-link
   auto-negotiation: done    done
               rate: 100Mbps 10Mbps
        full-duplex: yes     no
    poe-out-current: 124mA   0mA

SwOS

PoE Out controller with new firmware will enable certain monitoring features such as PoE Out state, current power usage and voltage supplied to the board:

  • PoE Out state - will enable to see PoE Out state remotely just by logging into the board
  • Current power usage - measured in Amperes will show current usage on the port
  • Supplied voltage - as this value directly impacts how much power can be given to the connected devices it is important to know value that is available to the SwOS device itself.

How it works

auto-on mode

If auto-on is selected then port operates in this strict order:

  • with low voltage it checks for resistance on the connected port. If it is detected that resistance is in range (3kΩ to 26.5kΩ) power is turned on;
  • when power is given it is continuously checked if overload limit is not reached or short circuit is detected
  • when cable is unplugged port returns in detection state and will remain off until suitable port that could accept PoE is detected

forced-on mode

If forced-on is selected then port operates in this strict order:

  • it is checked if resistance is in range is 0Ω to ∞Ω, so that even if cable is unplugged power will be given on the port
  • when power is given it is continuously checked if overload limit is not reached or short circuit is detected
  • when cable is unplugged port remains with power enabled on the port

Safety

PoE out feature has the following safety features:

Port eligibility detection for poe out

auto-on mode is considered safe, it will check if resistance on the port is within range and only then enable PoE out on the interface. The range is 3kΩ to 26.5kΩ

Overload protection

when port is on (PoE out is enabled) port is checked for overload, If that is detected to avoid hardware damage of powered device or powering device PoE out is turned of on this port.

With new firmware after overload is detected starts 120 second countdown after what PoE Out feature will be turned on again to see if environment has changed and device connected can be supplied with power again. That is important for configurations that are not connected to mains (solar installations, equipment running on batteries due to mains failure) so that when voltage drops - overload will be detected and connected devices turned off. After a while when voltage level returns to usual operating value - connected equipment can be powered on again.

Short circuit detection

when port is on (PoE out is enabled) port is checked for short circuit. If it is detected to ensure that there is no additional damage on powered device and no damage on powering device PoE out is turned off on all ports

PoE Out polarity

By default PoE out polarity on MikroTik manufactured devices on 100MBps ports is standard

Standard

PoE out on RouterBOARD devices is standard - over blue pair - positive and over brown pair - negative voltage

Reversed

Some devices use different polarity to power their devices that is reverse of the standard: over blue pair - negative and over brown pair - positive voltage

Any

Device that supports either of 2 possible polarities - either standard or reversed

Wiring

If you want to power device that supports only reverse polarity using 'RB750UP and OmniTik UPA you have to make special cable that will swap required wires, thus enabling you to power these devices.

On one end you have to have standard RJ45 T568B wiring (orange striped, orange, green striped, blue, blue striped, green, brown striped, brown) and on other and has to have blue and brown pair swapped resulting in (orange striped, orange, green striped, brown, brown striped, green, blue striped, blue)

RB750UP and OmniTik UPA-5HnD Powered devices

Table contain information on what devices can be powered using RB750UP and OmniTik UPA-5HnD as power source for PoE. Table contains devices that are explicitly tested. Routers from same series or with modifications will also work.

Polarity: standard - blue pair positive, brown pair negative; reversed - blue pair negative , brown pair positive, any - either standard or reversed.

Device forced-on auto-on polarity
RouterBOARD RB433GL [1] yes yes any
RouterBOARD RB450G [2] yes yes any
OmniTik UPA-5HnD [3] yes yes standard
OmniTik U-5HnD [4] yes yes standard
RouterBOARD RB711G-5HnD [5] yes yes any
RouterBOARD RB411U [6] yes yes standard
RouterBOARD RB800 [7] no no any
RouterBOARD RB450 [8] yes yes standard
RouterBOARD RB433AH [9] yes yes standard
RouterBOARD RB750 [10] yes yes standard
RouterBOARD RB750UP [11] yes yes standard
RouterBOARD RB435G [12] yes no any
RouterBOARD RB493AH [13] yes yes standard
RouterBOARD RB493 [14] yes yes standard
RouterBOARD RB532 yes yes standard
RouterBOARD RB153 yes yes standard
RouterBOARD RB112 yes yes standard
Motorolla Canopy yes yes reversed
Ubiquity LOCO900 yes yes standard
Ubiquity Bullet M2 yes yes standard
Ubiquity Bullet M5 yes yes standard
Ubiquity NanoStation 2N yes yes standard
Ubiquity NanoStation M365 yes yes standard
Ubiquity UniFi AP yes yes standard
Ubiquity UniFi AP long range yes yes standard

New PoE Out firmware

New PoE Out controller firmware will become our reality soon. These are some of the features that will definitely become available compared to current one:

Feature New FW Old FW
Overcurrent protection yes, configurable yes
Per port load monitoring yes (5.19) no
PoE Out status monitoring yes no
PoE Out logging yes no
Fast PoE Out on yes (5.19) no
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