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Revision as of 18:36, 26 October 2015 by Pauls (talk | contribs) (Power-cycle-ping)
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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.


Warning: When updated to newer PoE-Out controller firmware version it is not possible to downgrade it


Note: RouterOS is scapable to work with 1.x and 2.x firmware releases



Global settings

Global PoE settings (affects all ports) can be configured in /interface ethernet poe settings menu.

Property Desciption
version version of PoE controller firmware. It is independent of RouterOS and bootloader version.
ether1-poe-in-long-cable (default: no) setting to yes will disable short detection on all poe-out ports to enable use of longer ethernet cables. This is potentially dangerous settings and should be used with caution.

Note: Global setting of ether1-poe-in-long-cable is for PoE-in on ether1 interface on the router. Cable length that is used to power the router is important

Port settings

PoE Out can be configured in /interface ethernet poe menu. 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.

Starting from RouterOS 6.10 these configuration options are available:

Property Desciption
poe-out (default: auto-on)
  • 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.
poe-priority (0 .. 99, default: 10) set port priority regarding other PoE-Out ports. Highest priority is 0, lowest priority is 99. If there are 2 or more ports with similar priority then port with smallest port number will have higher priority. For example, if ether2 and ether3 are of same priority and over-current is detected then PoE-Out on ether3 will be turned off. Every 6 seconds ports will be checked for possibility to provide PoE-Out if it was turned off due to port priority.


In RouterOS poe-out has power-cycle-ping feature, which pings a host and power-cycles poe-out port, if this host does not respond. Power-cycle-ping settings can be changed in /interface ethernet poe set command.

Property Desciption
power-cycle-ping-enabled (default: auto-on) Enables ping watchdog, power-cycle port if it does not respond.
power-cycle-ping-address ( IPv4 | IPv6 | MAC ) Address to ping (icmp for IPv4 and IPv6, arp for IPv4, RouterOS mac-ping for MAC).
power-cycle-ping-timeout ( <integer> ) If ping fails for <timeout> duration, then 5s power-cycle is done.
power-cycle-interval ( none | <integer> ) If power is on for specified duration, then 5s power-cycle is done.

If power-cycle is enabled, /interface ethernet poe monitor will show:

  • power-cycle-host-alive ( yes | no ) - shows ping status. Is not shown, if ping is disabled or not done yet.
  • power-cycle-after ( time ) - shows time, how much is left till next power-cycle (because of ping timeout or power-cycle-interval).

Note: power-cycle-ping by default uses ICMP packets to check if host is reachable, if ICMP fails, it will use ARP ping, when both fails power-cycle is applied

Command Desciption
print prints all the properties in menu
export export setting of the current menu.
power-cycle (0s .. 1m, default: 5s) reset the power for specified duration, to power cycle a connected device
monitor shows poe-out-status of specified port

Settings in old RouterOS versions

Old firmware supported configuration features:

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.


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.


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


It is possible to monitor poe-out current usage in RouterOS via /interface ethernet poe menu. Monitoring currently will show power usage in watts, current load in amperes and supplied voltage.


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

off mode

If off mode is used, poe-out on the port will be turned off at all times and port on the router will behave as simple Ethernet port.


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.


Note: PoE-Out controller firmware version 2.0 allows 1A load on port with 2.2A of total limit on all ports

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


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


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


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


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 SXT[12] yes yes standard
RouterBOARD RB435G [13] yes no any
RouterBOARD RB493AH [14] yes yes standard
RouterBOARD RB493 [15] 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

Upgrade PoE Out firmware

PoE-Out controller firmware is not provided separately from RouterOS. For newer PoE-Out firmware it is required to install newer RouterOS release.


Note: Firmware upgrade is possible since RouterOS 5.20


Note: RouterOS 6.x does not have upgrade command and the upgrade/downgrade is done automatically as you are upgrading or downgrading RouterOS.

Upgrade procedure is as follows:

  • upgrade router with newest RouterOS release.
  • check current firmware using /interface ethernet poe settings print command
  • to upgrade issue /interface ethernet poe settings upgrade command
  • when prompted with this message follow instructions as required
 Do you really want to upgrade PoE firmware? [y/n] 
  • you have to reboot the router for changes to take place
Please reboot to finish PoE firmware upgrade.
  • reboot the router


If for some reason POE-Out controller firmware update fails you have to follow these steps and firmware upgrade should succede:

  • Downgrade RouterOS to 5.21
  • Do /interface ethernet poe settings upgrade
  • Upgrade back to 5.24 and issue command again /interface ethernet poe settings upgrade

This should result in newest PoE-Out controller firmware.

PoE Out examples

PoE-Out firmware starting from 2.0 allows to set port priority. Priority of 0 is the highest priority there is, so if your installation is going over power budged port with the lowest priority is going to be turned off first.

setting up priority

here is example on how priorities look

setting up priorities:

/interface ethernet poe set ether2 poe-priority=10
/interface ethernet poe set ether3 poe-priority=13
/interface ethernet poe set ether4 poe-priority=11
/interface ethernet poe set ether5 poe-priority=14

what will happen when power budget will go over set total limit - first, if over-load is detected ether5 will be turned off, then recheck is done and if still total limit over-load is detected next port in priority will be turned off, in this example, ether3 will have its poe-out turned off. Both of these ports will be reched every 6 seconds is it possible to turn poe-out on for these ports. Power up will happen in reverse order as the power was cut.

same priority

if all, or some ports will have same poe-priority than port with lower port number will have higher priority

/interface ethernet poe set ether2 poe-priority=10
/interface ethernet poe set ether3 poe-priority=10
/interface ethernet poe set ether4 poe-priority=10
/interface ethernet poe set ether5 poe-priority=10

in this example, if over-load total limit is reached ether5 will be turned off first, then ether4 then ether3 as all of these ports have same poe priority.

monitoring poe-out

all the monitoring of poe-out can be done via /interface ethernet poe monitor <interface> menu

[admin@MikroTik] > interface ethernet poe monitor [find]
              name: ether2 ether3 ether4 ether5
   poe-out-voltage: 23.2V  23.2V  23.2V  
   poe-out-current: 224mA  116mA  64mA   
     poe-out-power: 5.1W   2.6W   1.4W 

here RB750UP is powering up 3 devices on ports ether2, ether3 and ether4

Changes between 1.x and 2.0 PoE-Out controller firmware

feature version 1.x version 2.0
max limit on port 500mA 1A
total limit 2A 2.2A
poe-priority not available per port priority adjustable
monitoring not available information about each port
PoE in long cable mode not available available
Check PoE controller FW version newer RouterOS available