Manual:PoE-Out

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

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.

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

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

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 RB800 [6]	no	no	any
RouterBOARD RB450 [7]	yes	yes	standard
RouterBOARD RB433AH [8]	yes	yes	standard
RouterBOARD RB750 [9]	yes	yes	standard
RouterBOARD RB750UP [10]	yes	yes	standard
RouterBOARD RB435G [11]	yes	yes	any
RouterBOARD RB493AH [12]	yes	yes	standard
RouterBOARD RB493 [13]	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