Mikrotik hex poe lite нет питания на рое от блока питания
PoE-Out Configuration
PoE Configuration is supported on all MikroTik devices with PoE-Out interfaces, the configurations can be edited from the RouterOS and SwOS interfaces.
PoE-Out Logs
By default PoE-Out event logging is enabled and uses "warning" and "info" topics to notify the user about PoE-Out state changes. Log entries will be added on each PoE-Out state change. Important logs will be added with "warning" topic, informative logs will be added with "info" topic.
To avoid unnecessary logging in cases when PD is not powered because of current-too-low, RouterOS will filter such events, and add one log per every 512 current-too-low events.
Logs can be disabled if necessary:
PoE-Out limitations
It is important to check PoE-Out specification to find out hardware limitations because it can differ between models
PoE-Out port limitation
PoE-Out ports are limited with max amp values which are supported in particular voltage, usually max current will differ for low voltage devices (up to 30 V), and for high voltage devices (31 to 57 V).
PoE-Out total limitation
PSE has also a total PoE-Out current limitation which can't be exceeded, even if the individual port limit allows it.
PoE Out polarity
All MikroTik PSE uses the same PoE-Out pin polarity Mode B4,5 (+) and 7,8 (-), however other vendors can use opposite or Mode A pinout on PD. Reverse polarity would require using a crossover cable but Mode A PD would require Mode B to Mode A converter.
Note: Passive PD with high input inrush current can result in overcurrent protection on PSE, make sure that PD specification supports powering from PSE (not only from the passive power injector)
Legacy
PoE-Out Monitoring
Коммутаторы MikroTik с поддержкой PoE
В этой статье описаны модели устройств MikroTik с поддержкой питания устройств по PoE, особенности выбора оборудования и проектирования сети с PoE-устройствами.
Все PoE-устройства MikroTik поддерживают выдачу питания по технологии Passive PoE. Большинство устройств имеет возможность принимать питание по PoE на 1 порту Ethernet. Данная техническая возможность может быть использована в качестве резервного источника питания, в случае выхода из строя основного.
Рис.3. Поддержка питания Passive PoE на 1 порту MikroTik hEX.
Амплитуда выходного напряжения PoE зависит от блока питания устройства. При внешнем блоке питания 24В амплитуда выходного напряжения PoE также будет равна 24В. Для питания устройств по стандарту IEEE 802.3af/at следует использовать блок питания 48В, приобретаемый отдельно для некоторых устройств. Существуют как модели с поддержкой нескольких внешних блоков питания разной амплитуды, так и модели с внутренним блоком питания с возможностью выбора амплитуды.
RouterOS
Usage
RouterOS provides an option to configure PoE-Out over Winbox, Webfig and CLI, basic commands using the CLI are
Property | Description |
---|---|
print ( ) | Prints PoE-Out related settings. |
export ( ) | export is displayed under /interface ethernet menu. |
monitor (string| interface) | Shows poe-out-status of a specified port, or all ports with /interface ethernet poe monitor [find] command. |
power-cycle (time:0..1m |; Default: 5s) | Disables PoE-Out power for a specified period of time. |
Global Settings
Some MikroTik PoE-Out devices support global PoE setting which can be configured under /interface ethernet poe settings menu. Global setting ether1-poe-in-long-cable feature disables strict input/output current monitoring (short detection) to allow the use of PoE-Out with long ethernet cables and/or avoiding improper short-circuit detection.
Property | Description |
---|---|
ether1-poe-in-long-cable (yes | no) | Setting it to "yes" will disable short detection on all poe-out ports. This is potentially dangerous settings and should be used with caution |
Note: Global setting of ether1-poe-in-long-cable can also affect PoE-Out behaviour on PSE which is powered using a DC connector
Port Settings
PoE-Out can be configured under /interface ethernet poe menu. Each port can be controlled independently.
- auto-on - the 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 the range from 3kΩ to 26.5kΩ
- 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
Highest priority is 0, lowest priority is 99. If there are 2 or more ports with the same priority then port with the smallest port number will have a higher priority. For example, if ether2 and ether3 have the same priority and over-current is detected then PoE-Out on ether3 will be turned off.
Power-cycle settings
RouterOS provides a possibility to monitor PD using a ping, and power-cycle a PoE-Out port when the host does not respond. power-cycle-ping feature can be enabled under /interface ethernet poe menu.
Property | Description |
---|---|
power-cycle-ping-enabled (yes | no; Default: no) | Enables ping watchdog, power-cycles port if a host does not respond to ICMP or MAC-Telnet packets. |
power-cycle-ping-address (IPv4 | IPv6 | MAC; Default: ) | An address which will be monitored. Since RouterOS 6.46beta16, an active route towards PD is required in case an IP address is configured, so make sure PSE can reach the PD. In case MAC address is specified, PSE will send MAC-Telnet ping requests only from specified ethernet interface. When configuring a bridge vlan-filtering or some way of VLAN switching, it is recommended to use IP address for monitoring your PD. |
power-cycle-ping-timeout (time:0..1h |; Default: 5s) | If the host does not respond for more than period of time, then PoE-Out port is switched off for 5s. |
power-cycle-interval (time| any; Default: ) | Disables PoE-Out power for 5s between specified interval. Not related with power-cycle-ping feature. |
If power-cycle is enabled, /interface ethernet poe monitor will show actual status of the host and time when power cycle will be performed [1]
SwOS interface provides basic PoE-Out configuration options:
- PoE Out - Change between PoE-out modes (auto/on/off)
- PoE Priority - Change the Priority of port (0. 8)
- Voltage Level - Change between two voltage outputs on PoE-Out ports (auto/low/high)
PoE-Out notifications
Same priority
if all, or some ports will have the same poe-priority, then port with the lowest port number will have higher priority
In this example, if the total PoE-Out limit is reached ether5 will be turned off first, then ether4 then ether3 as all of these ports have same poe priority.
PoE-Out Controller upgrade
PoE-Out devices which are running RouterOS 5.x can also hold old PoE-Out controller firmware, upgrade to RouterOS 6.x will automatically update the PoE-Out firmware. Changes between 1.x and 2.x PoE-Out controller firmware will result in higher Max-port limits (0.5A to 1A) in case if it's supported by the hardware, also will provide some additional data which can be monitored, and allow to use PoE-Out priorities.
All MikroTik devices which come with RouterOS 6.x already support the latest PoE-Out firmware.
г. Санкт-Петербург, Крестовский остров, Северная дорога, дом 12.
г. Санкт-Петербург, ст. м. «Василеостровская»,
ул. Уральская, д. 17, корпус 3, этаж 2
В данной статье рассматриваем коммутаторы Микротик PoE и помогаем с выбором нужного устройства.
Troubleshooting
In cases where a PD does not power-up or reboots unexpectedly when powered from your PSE, it's suggested to the first check:
- PD supported input voltage - PSE output voltage must be in the range supported by the PD. Otherwise, the PD is incompatible with the PSE, and will not be able to power-up. Check the PD datasheet.
- PD supported input PoE-in standard - Some PDs do not support af/at standard even if it has PoE-in support up to 57 V, check PD datasheet.
- PD is rebooted from PSE
- Check if PD does not exceed PoE-Out port limit and Total-PoE-Out port limit of the PSE, check PSE datasheet.
- Check if the Voltage limit does not drop bellow supported (Can be caused by voltage drop on the wires).
- Check if you are using a proper power supply, the output power of PSU should be calculated from:
- Check if you are using good quality ethernet cables, it's important especially in cases if PoE is used.
- There can be cases where a PD does not power up, even though it supports passive PoE, and does not consume more power than the specified PSE port limit. This can be caused by inrush current triggering overcurrent protection on the PSE. Make sure that PD specification supports powering from PSE (not only from passive power injector)
- Polarity - Devices with opposite or different pinouts can be unable to powerup from all PSE. Check the PD datasheet.
- Incompatible resistance - PD resistance should have ranged from 3kΩ to 26.5kΩ (For Passive-PoE) and from 23.75kΩ to 26.25kΩ on af/at.
How it works
RouterOS
MikroTik devices with PoE-Out controller (not injector) provides port monitoring option. /interface ethernet poe monitor [find]
- powered-on - Power is applied to the port, and PoE-Out is operating normally,
- waiting-for-load - PSE attempts to detect if power can be applied to the port. For power-on to happen there should be resistance on spare pairs in the range from 3kΩ to 26.5kΩ;
- short-circuit - Short-circuit is detected on PoE-Out port, power is switched off, the only detection with low voltage takes place.
- overload - The PoE-Out current limit is exceeded, power is switched off on PoE-Out port. For port limits see each model specifications.
- voltage-too-low - PD can not be powered with voltage provided from PSE.
- current-too-low - current-too-low means that PD draws too low current ( <10mA) than normal PoE-Out device should, reason for this can be:
Delivered voltage at PD is too low for normal powering (for example Vmin = >30V, but provided 24V);
PD uses second power source which has a higher voltage than PSE, so all current is taken from second DC source, not PSE PoE-Out port;
- off - all detection and power is turned off for this port;
If power-cycle-ping feature is used, /interface ethernet poe monitor [find] will show additional fields:
It is possible to monitor PoE-Out values using SNMP protocol, this requires enabled SNMP on PSE. SNMP Wiki
SNMP OID tables:
- 1.3.6.1.4.1.14988.1.1.15.1.1.1 - interface id
- 1.3.6.1.4.1.14988.1.1.15.1.1.2 - interface names
- 1.3.6.1.4.1.14988.1.1.15.1.1.4 - voltage in dV (decivolt)
- 1.3.6.1.4.1.14988.1.1.15.1.1.5 - current in mA
- 1.3.6.1.4.1.14988.1.1.15.1.1.6 - power usage in dW (deviwatt)
SNMP values can be requested also from the RouterOS, for example, snmp-walk will print current mA from all available PoE-Out ports:
To get very specific OID value, use snmp-get tool (displays current mA on ether3 interface):
A PoE-Out controller will enable certain monitoring features also from SwOS, such as PoE-Out Status, PoE-Out Current, PoE-Out Voltage and PoE-Out Power usage.
PoE-Out Warnings in GUI/CLI
To notify a user about important PoE-Out related problems, messages will be shown in Winbox / WebFig and CLI interface fields:
1 RS ;;; poe-out status: overload
ether1 ether 1500 1588 9204 64:D1:54:61:D5:E0WebFig and Winbox will notify user under interfaces:
Legacy
PoE-Out LEDs
Models with dependant voltage output
PoE-Out LED behavior can differ between models, but most of them will indicate PoE-Out state on one additional LED. Devices with one voltage output will light:
- Red color LED - PoE-Out port state is powered-on (auto or forced-on mode).
- Blinking Red color LED - PoE-Out port state is short-circuit
Models with selectable voltage output
Models with multiple voltage options can indicate additional information:
- Green color triangle LED - PoE-Out port state is powered-on (auto or forced-on mode), PD uses low voltage.
- Red color triangle LED - PoE-Out port state is powered-on (auto or forced-on mode), PD uses high voltage (af/at or passive).
- Blinking Green color triangle LED - PoE-Out port state (low voltage) is short-circuit or overload
- Blinking Red color triangle LED - PoE-Out port state (high voltage) is short-circuit or overload
Model-specific LED behavior
-
- All PoE LEDs flashing: wrong voltage PSU plugged into one of the ports.
- netPower 16P - All PoE LEDs flashing: wrong voltage PSU plugged into one of the ports. - indicates an exceeded overall max PoE output limit. Port PoE-Out priorities will work in 3 independent sections (8 ports each) and overload will happen in any section that breaches 150W consumption.
PoE-Out Monitoring
Same priority
if all, or some ports will have the same poe-priority, then port with the lowest 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 the total PoE-Out limit is reached ether5 will be turned off first, then ether4 then ether3 as all of these ports have same poe priority.
PoE-Out Modes
auto-on mode
If auto-on is selected on PoE-Out interface, then port operates in this strict order:
- PSE with low voltage checks for a resistance on the connected port. If detected resistance range is between (3kΩ to 26.5kΩ) power is turned on;
- When power is applied, the PSE continuously checks if overload limit is not reached or short circuit detected
- If the cable is unplugged, the port returns in detection state and will remain off until suitable PD is detected
forced-on mode
If forced-on is selected then port operates in this strict order:
- PSE disables resistance check on the port, and apply power on pins 4,5 (+) and 7,8 (-), even if no cable is attached
- When power is applied, PSE still continuously checks if an overload or short circuit is not detected
- After the cable is unplugged, the power still remains enabled on the port.
off mode
If off mode is used, PoE-Out on the port will be turned off, no detection will take place, and interface will behave as a simple Ethernet port.
PoE-Out Configuration
PoE Configuration is supported on all MikroTik devices with PoE-Out interfaces, the configurations can be edited from the RouterOS and SwOS interfaces.
PoE-Out Controller upgrade
PoE-Out devices which are running RouterOS 5.x can also hold old PoE-Out controller firmware, upgrade to RouterOS 6.x will automatically update the PoE-Out firmware. Changes between 1.x and 2.x PoE-Out controller firmware will result in higher Max-port limits (0.5A to 1A) in case if it's supported by the hardware, also will provide some additional data which can be monitored, and allow to use PoE-Out priorities.
All MikroTik devices which come with RouterOS 6.x already support the latest PoE-Out firmware.
Power over Ethernet (PoE) — технология, позволяющая передавать удалённому устройству вместе с данными электрическую энергию через стандартную витую пару в сети Ethernet. Данная технология предназначается для IP-телефонии, точек доступа беспроводных сетей, IP-камер, сетевых концентраторов и других устройств, к которым нежелательно или невозможно проводить отдельный электрический кабель.
1. Как работает PoE в микротиках? По какому протоколу? У микротиков "свой" PoE не совместимый со стандартом 802.3af. В документации это называется "Passive PoE. Non 802.3af". Используются ДВЕ ПАРЫ - синяя и коричневая. Синяя - Плюс. коричневая - Минус.
2. Какие ограничения на порт по питанию? из вики - "max limit on port - 1A, total limit - 2.2A"
4. При процедуре обновления, помимо обновления самой системы и загрузчика, на данных устройствах также необходимо выполнить обновления микропрограммы PoE. Выполняется командой
/interface ethernet poe settings upgrade
(внимание! из официальной википедии - "Warning: When updated to newer PoE-Out controller firmware version it is not possible to downgrade it", невозможно понизить версию прошивки PoE)
5. Просмотреть текущее состояние PoE можно командой
interface ethernet poe monitor [find]
6. Основные параметры PoE
auto-on - Роутер пытается определить требуется ли подавать питание или нет. Проверяет сопротивление на парах ( 3kΩ to 26.5kΩ) и если его нет, то подаёт.
forced-on - отключено тестирование по сопротивлению. В результате PoE включено всегда. (хотя после обновления, он в любом случае проверяет, даже при данном параметре)
off - все проверки отключены и питание на порт не подаётся..
6. Приоритет - выставляется параметром poe-priority. Чем меньше число, тем выше приоритет
/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
В данном примере, при проблемах с питанием (перегрузка, проблемы со входным питанием (к примеру при переключении на работу от ИБП)), вначале отключиться ether5, как имеющий наибольшее значение poe-priority. Затем будет отключен ether3, затем ether4. И только в самом конце ether2. Это может пригодиться к примеру, если подключены коммутаторы офисных компьютеров и серверов, а работа серверов важнее и мы гасим автоматом офисный коммутатор. Или постепенное отключение Wifi-точек доступа не являющихся критичными.
Если параметр poe-priority не указан или у всех указан одинаковый, то отключаться будет последовательно начиная с последнего порта (вначале ether5, затем ether4 и так далее)
7. Для чего используется параметр ether1-poe-in-long-cable? - фраза с официальной вики "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.". Данный параметр отключает проверку на короткое замыкание в линии НА ВСЕХ OUT-портах, что позволяет использовать более длинные кабели. Это потенциально опасная настройка и использовать её надо осторожно.
Правда мне данный параметр непонятен. В тестах, на 90 метровом куске кабеля, 750UP смог поднять 951G-2HnD. Может пригодится если больше длина или менее качественный кабель используется.
C использованием высокочастотных трансформаторов на обоих концах линии с центральным отводом от обмоток постоянное напряжение питания подается на центральные отводы вторичных обмоток этих трансформаторов, и так же с центральных отводов снимается на приемной стороне. Использование центральных отводов сигнальных трансформаторов позволяет без взаимного влияния передавать питание по сигнальным парам, то есть передавать по одним и тем же проводникам и высокочастотные данные, и постоянное напряжение питания.
11. Можно ли сжечь оборудование, которое не поддерживает Passive PoE, подключив его к микротику выдающему питание по PPoE? Да можно. Passive PoE в режиме forced-on, по сути, банально использует синюю и коричневую пары для питания (Синий +, Коричневый -). Хотя в версии прошивки PoE выше 2.0 и на режиме forced-on выполняется проверка, но риск сжечь устройство (или отдельный порт, всё равно сохраняется)
PS: ВНИМАТЕЛЬНО ПРОВЕРЯЙТЕ КАБЕЛЬ. НИ В КОЕМ СЛУЧАЕ НЕ ИСПОЛЬЗУЙТЕ ПРИ РАБОТЕ С PoE ОМЕДНЁННЫЙ. ТОЛЬКО ЧИСТУЮ МЕДЬ. Узнать кабель, который использовать нельзя можно по маркировкам - CCA, CA, CCS. (да и вообще никогда не используйте омеднёный кабель)
Wed Aug 15, 2018 3:37 am
Hi, I use mikrotik hex s and hap ac2 ( hap ac2 - poe in ). hex s has 24V 1,2A power supply, but hap ac2 works unstable - I think it does not have enough power. What do I need to do - replace the power supply with a more powerful one?
Trainer
Wed Aug 15, 2018 4:07 pm
hEX S max power draw = 11W
hAP ac2 max power draw = 15W
Total maximum power draw = 26W. hEX S PSU is 24V @ 1.2A = 28W.
Tight, but these are maximum power draw values. Have you tried powering the hAP ac2 on its own to see if is still unstable? How long is the cable going to the hAP ac2?
Yes, you can test replacing the PSU with a more powerful one.
Thu Aug 16, 2018 11:06 pm
I bought a more power PSU ( 24V, 2.5 A ), but problem not solved. Cable 15 m maximum. I think that protection by current (500ma) in the device on hEX S works. To power the HAP AC2 I had to use POE RBGPOE + Hex S ( from single PSU 24V, 2.5 A ) - all work fine. Why then the support POE is made on hEX S?
Fri Aug 17, 2018 5:27 pm
One thing is limitation on PoE out current on some devices. I guess it is nice to have possibility to power some low-powered device directly off main router or switch. Example of such device would be simple WAP - single frequency, not many Tx chains.
PoE in is a completely different matter, sometimes it is handy to provide power to higher-power device over UTP cables. In such cases one use RBGPOE injector.
BTW, in some production environment it is not sound to have single power source (e.g. one switch) if that one doesn't have highly advanced power management built in (and basic PoE out devices by Mikrotik don't have very sofisticated power management built in). It can easily happen that malfunction of one device takes down all other devices, powered from same power source. Another thing not to be done IMHO is daisy-chaining power supply (e.g. switch -> device1 -> device 2) as power overload can easily happen taking down both PoE powered devices.
Trainer
Sat Aug 18, 2018 12:08 pm
Other Mikrotik PoE switches can output up to 1A per port. Don't know the specific case for the hEX S as is a recent device and not a word about output limits on its last port on the specs, so it may be the case.
Again, this is the Maximum power draw by hAP ac2, won't be surprised if average draw is less than 300mA.
Did you force poe to on on the hEX S when powering the hAP ac2 or left it on auto?
Mon Aug 20, 2018 4:45 pm
Hi, I use mikrotik hex s and hap ac2 ( hap ac2 - poe in ). hex s has 24V 1,2A power supply, but hap ac2 works unstable - I think it does not have enough power. What do I need to do - replace the power supply with a more powerful one?
Hi, I have similar problem here with these two boxes, but my hAP ac2 does not power up at all and hEX S' ether5 LED periodically (approx 1s) blinks red for short time (<100ms). Before hEX S, the power supplying box was RB2011 with PoE-out on ether10 and I've experienced no problems with powering hAP ac2.
I've tried to connect hEX S' port ether5 to:
- hAP ac lite - ether1
- hEX lite (RB750r2) - ether1
- RB2011 - ether1
and all these boxes started when powerfed from hEX S.
Just another experiment, I've connected hEX S' ether5 with PoE-out turned off to hAP ac2 ether1 and powered the hAP ac2 via external adapter. After hAP ac2 started, I've enabled PoE-out on hEX S' ether5 and disconnected external adapter from hAP ac2 - and the hAP ac2 continued to run. It seems that hAP ac2 causes current peaks that hEX S cannot sustain or some form of overcurrent protection cuts off the power. although no messages related to poe-out were logged.
PoE Out examples
RouterOS allows us to define priorities on PoE-Out ports, so if your installation is going overpower budget, the PSE will disable less important PD with the lowest priority.
The priority of 0 is the highest priority, 99 - lowest
Рассмотрим подробнее коммутаторы Микротик, которые выдают питание POE:
PoE коммутатор MikroTik RB260GSP — это небольшой управляемый коммутатор, работающий под управлением SwitchOS. Он оснащён SFP-портом и 5 Ethernet-портами 100/1000 МБит/с. На портах 2-5 предусмотрена возможность выдачи питания Passive PoE. Максимальная мощность одного порта — 30 Вт, суммарная максимальная мощность PoE-нагрузки — 48 Вт. Данный коммутатор поддерживает входное напряжение 11-30 В, поэтому он не подходит для питания PoE-устройств по стандарту IEEE 802.3af/at. В комплекте с устройством поставляется внешний блок питания повышенной мощности — 24 В 2,5 А.
Устройства hEX PoE Lite и PowerBox также имеют функцию Passive PoE на портах 2-5. В отличие от RB260GSP эти устройства работают под управлением RouterOS, т.е. могут выполнять функцию роутера. Скорость Ethernet-портов ограничена 100 Мбит/с. Роутер hEX PoE Lite оснащён USB-портом для установки LTE-модема. Устройство PowerBox имеет влагозащищённое исполнение корпуса для установки на улице. Максимальная мощность одного порта — 30 Вт, суммарная максимальная мощность PoE-нагрузки — 48 Вт. В комплекте с устройствами поставляется внешний блок питания повышенной мощности – 24 В 2,5 А.
Troubleshooting
In cases where a PD does not power-up or reboots unexpectedly when powered from your PSE, it's suggested to first check:
- PD supported input voltage - PSE output voltage must be in the range supported by the PD. Otherwise the PD is incompatible with the PSE, and will not be able to power-up. Check the PD datasheet.
- PD supported input PoE-in standard - Some PDs do not support af/at standard even if it has PoE-in support up to 57 V, check PD datasheet.
- PD is rebooted from PSE
- Check if PD does not exceed PoE-Out port limit and Total-PoE-Out port limit of the PSE, check PSE datasheet.
- Check if Voltage limit does not drop bellow supported (Can be caused by voltage drop on the wires).
- Check if you are using a proper power supply, the output power of PSU should be calculated from:
- Check if you are using good quality ethernet cables, it's important especially in cases if PoE is used.
- There can be cases where a PD does not power up, even though it supports passive PoE, and does not consume more power than the specified PSE port limit. This can be caused by inrush current triggering overcurrent protection on the PSE. Make sure that PD specification supports powering from PSE (not only from passive power injector)
- Polarity - Devices with opposite or different pinout can be unable to powerup from all PSE. Check PD datasheet.
- Incompatible resistance - PD resistance on spare pairs should have range from 3kΩ to 26.5kΩ (For Passive-PoE) and from 23.75kΩ to 26.25kΩ on af/at.
Model-specific features
Safety
PSE has following safety features:
PoE-Out compatibility detection
The auto-on mode is considered safe, it will check if the resistance on the port is within allowed range and only then enable PoE out on the interface. The range is 3kΩ to 26.5kΩ
Overload protection
When a PoE-Out port is powered-on, it is constantly checked for overload. If overload is detected, PoE-Out is turned off on the port to avoid damage to the PD or PSE.
In seconds the PoE Out feature will be turned on again to see if the environment has changed and PD 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 up again.
Short circuit detection
When power is enabled on PoE-Out port, PSE continuously checks for a short circuit. If it is detected to ensure that there is no additional damage on PD and PSE, the power is turned off on all ports. PSE will continue to check PoE-Out port until environment returns to normal.
Warning: Make sure that non-standard incompatible PD which does not have the resistance range 3kΩ to 26.5kΩ are not attached, so the PSE would not try to apply power on them
RouterOS
MikroTik devices with PoE-Out controller (not injector) provides port monitoring option. /interface ethernet poe monitor [find]
- powered-on - Power is applied to the port, and PoE-Out is operating normally,
- waiting-for-load - PSE attempts to detect if power can be applied to the port. For powering there should be resistance in the range from 3kΩ to 26.5kΩ;
- short-circuit - Short-circuit is detected on PoE-Out port, power is switched off, the only detection with low voltage takes place.
- overload - The PoE-Out current limit is exceeded, power is switched off on PoE-Out port. For port limits see each model specifications.
- voltage-too-low - PD can not be powered with the voltage provided from PSE.
- current-too-low - current-too-low means that PD draws too low current ( <10mA) than normal PoE-Out device should, the reason for this can be:
The delivered voltage at PD is too low for normal powering (for example Vmin =>30V, but provided 24V);
PD uses a second power source which has a higher voltage than PSE, so all current is taken from the second DC source, not PSE PoE-Out port;
- off - all detection and power is turned off for this port;
If power-cycle-ping feature is used, /interface ethernet poe monitor [find] will show additional fields:
power-cycle-host-alive: (Shows if monitored host is reachable)
power-cycle-after: (Shows time, after which the port will be power-cycled)It is possible to monitor PoE-Out values using SNMP protocol, this requires enabled SNMP on PSE. SNMP Wiki
SNMP OID tables:
- 1.3.6.1.4.1.14988.1.1.15.1.1.1 - interface-id
- 1.3.6.1.4.1.14988.1.1.15.1.1.2 - interface names
- 1.3.6.1.4.1.14988.1.1.15.1.1.4 - voltage in dV (decivolt)
- 1.3.6.1.4.1.14988.1.1.15.1.1.5 - current in mA
- 1.3.6.1.4.1.14988.1.1.15.1.1.6 - power usage in dW (deviwatt)
SNMP values can be requested also from the RouterOS, for example, snmp-walk will print current mA from all available PoE-Out ports:
/tool snmp-walk address=10.155.149.252 oid=1.3.6.1.4.1.14988.1.1.15.1.1.5
To get very specific OID value, use snmp-get tool (displays current mA on ether3 interface):
tool snmp-get address=10.155.149.252 oid=1.3.6.1.4.1.14988.1.1.15.1.1.5.3
A PoE-Out controller will enable certain monitoring features also from SwOS, such as PoE-Out Status, PoE-Out Current, PoE-Out Voltage, and PoE-Out Power usage.
PoE Out examples
RouterOS allows to define priorities on PoE-Out ports, so if your installation is going over power budget, the PSE will disable less important PD with the lowest priority.
Priority of 0 is the highest priority, 99 - lowest
Power-cycle ping
/interface ethernet poe set ether1 power-cycle-ping-enabled=yes power-cycle-ping-address=192.168.88.10 power-cycle-ping-timeout=30s
In this example, PD attached to ether1 will be continuously monitored using a power-cycle-ping feature, which will send ICMP ping requests and wait for a reply. If PD with IP address 192.168.88.10 will not respond for more than 30s, the PoE-Out port will be switched off for 5s.
PoE-Out Warnings in GUI/CLI
To notify a user about important PoE-Out related problems, messages will be shown in Winbox / Webig and CLI interface fields:
Webfig and Winbox will notify user under interfaces:
PoE-Out notifications
Monitoring PoE-Out
PoE-Out ports can be monitored using a command /interface ethernet poe monitor
Setting up priority
Example of how to set priorities from CLI:
What will happen when power budget will go over total PoE-Out limit - first, if overload is detected, ether5 will be turned off (lowest priority), then recheck is done and if still total limit overload is detected next port in priority will be turned off, in this example, ether3 will be turned off. Both of these ports will be reached every few seconds to check if it is possible to turn PoE-Out on for these ports. Power up will happen in reverse order as the power was cut.
Safety
PSE has the following safety features:
PoE-Out compatibility detection
The auto-on mode is considered safe, it will check if the resistance on the port is within allowed range and only then enable PoE out on the interface. The range is 3kΩ to 26.5kΩ
Overload protection
When a PoE-Out port is powered-on, it is constantly checked for overload. If the overload is detected, PoE-Out is turned off on the port to avoid damage to the PD or PSE.
In seconds the PoE Out feature will be turned on again to see if the environment has changed and PD 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 the voltage level returns to usual operating value - connected equipment can be powered up again.
Short circuit detection
When power is enabled on PoE-Out port, PSE continuously checks for a short circuit. If it is detected to ensure that there is no additional damage to PD and PSE, the power is turned off on all ports. PSE will continue to check PoE-Out port until the environment returns to normal.
Warning: Make sure that non-standard incompatible PD which does not have the resistance range 3kΩ to 26.5kΩ are not attached, so the PSE would not try to apply power on them
MikroTik supported PoE-Out standards
MikroTik devices can support some or all of the following PoE standards:
Each PoE-Out implementation supports overload and short-circuit detection.
Note: Some MikroTik devices support all of the described standards (e.g. hEX PoE, PowerBOX Pro, CRS112-8P-4S-IN etc. )
Monitoring PoE-Out
PoE-Out ports can be monitored using a command /interface ethernet poe monitor
[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 1.4WХарактеристики стандартов PoE
Технические параметры технологии описаны в стандартах IEEE 802.3af PoE (2003 г.), IEEE 802.3at PoE+ (2009 г.), IEEE 802.3bt PoE++ (2018). Также существует технология Passive PoE, которая отличается односторонним способом работы с питающими устройствами.
Наиболее часто используется стандарт питания 802.3af, поддержка питания устройств мощностью до 12,95 Вт. Стандарт 802.3at незначительно отличается значением питающего напряжения, а также поддерживает более мощные устройства до 25,5 Вт. Стандарт 802.3bt описывает способ питания устройств повышенной мощности – до 71,3 Вт. Это обеспечивается за счёт выдачи питания по 8 проводникам витой пары, обязательно необходима поддержка стандарта клиентским устройством. Всегда при выборе коммутатора с POE проверяйте техническую документацию, какой стандарт питания поддерживает коммутатор на отдачу и оконечное устройство на получение.
В статье пойдёт речь о стандартах 802.3af/at и Passive PoE.
Setting up priority
Example of how to set priorities from CLI:
/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=14What will happen when power budget will go over total PoE-Out limit - first if the overload is detected, ether5 will be turned off (lowest priority), then recheck is done and if the still total limit overload is detected next port in priority will be turned off, in this example, ether3 will be turned off. Both of these ports will be reached every few seconds to check if it is possible to turn PoE-Out on for these ports. Power up will happen in reverse order as the power was cut.
PoE-Out limitations
It is important to check PoE-Out specification to find out hardware limitations because it can differ between models
PoE-Out port limitation
PoE-Out ports are limited with max amp values which are supported in particular voltage, usually max current will differ for low voltage devices (up to 30 V), and for high voltage devices (31 to 57 V).
PoE-Out total limitation
PSE has also a total PoE-Out current limitation which can't be exceeded, even if individual port limit allows it.
PoE Out polarity
All MikroTik PSE uses the same PoE-Out pin polarity Mode B4,5 (+) and 7,8 (-), however other vendors can use opposite or Mode A pinout on PD. Reverse polarity would require using a crossover cable but Mode A PD would require Mode B to Mode A converter.
Note: Passive PD with high input inrush current can result in overcurrent protection on PSE, make sure that PD specification supports powering from PSE (not only from the passive power injector)
PoE-Out Modes
auto-on mode
If auto-on is selected on PoE-Out interface, then port operates in this strict order:
- PSE with low voltage checks for resistance on the connected port. If the detected resistance range is between (3kΩ to 26.5kΩ) power is turned on;
- When power is applied, the PSE continuously checks if the overload limit is not reached or short circuit detected
- If the cable is unplugged, the port returns in detection state and will remain off until suitable PD is detected
forced-on mode
If forced-on is selected then port operates in this strict order:
- PSE disables resistance check on the port, and apply power on pins 4,5 (+) and 7,8 (-), even if no cable is attached
- When power is applied, PSE still continuously checks if an overload or short circuit is not detected
- After the cable is unplugged, the power still remains enabled on the port.
off mode
If off mode is used, PoE-Out on the port will be turned off, no detection will take place, and the interface will behave like a simple Ethernet port.
How it works
Power-cycle ping
In this example, PD attached to ether1 will be continuously monitored using a power-cycle-ping feature, which will send ICMP ping requests and wait for a reply. If PD with IP address 192.168.88.10 will not respond for more than 30s, the PoE-Out port will be switched off for 5s.
MikroTik supported PoE-Out standards
MikroTik devices can support some or all of the following PoE standards:
- Passive PoE-Out up to 30 V - PoE standard, which does not require negotiation between PSE (Power Sourcing Equipment) and PD (Powered Device). PoE-out uses the same voltage as supplied to the PSE (Power Sourcing Equipment). PoE-Out Standard for devices that supports input voltage up to 30 V. PD resistance should have ranged from 3kΩ to 26.5kΩ. (e.g. hEX PoE lite, RB3011UiAS-RM, RB2011iL-IN.)
- Passive PoE-Out up to 57 V - Works the same as low voltage (up to 30 V) PoE-Out, but is also capable to deliver high voltage over PoE ports. The output voltage depends on the power source connected to PSE. Can power up af/at compatible devices, which accepts power over 4,5 (+) and 7,8 (-), and does not require PoE negotiation. PD resistance should have ranged from 3kΩ to 26.5kΩ. (e.g. cAP ac, hAP ac, wsAP ac lite.)
Each PoE-Out implementation supports overload and short-circuits detection.
Model-specific features
PoE-Out Logs
By default PoE-Out, event logging is enabled and uses "warning" and "info" topics to notify the user about PoE-Out state changes. Log entries will be added to each PoE-Out state change. Important logs will be added with a "warning" topic, informative logs will be added with the "info" topic.
To avoid unnecessary logging in cases when PD is not powered because of current-too-low, RouterOS will filter such events, and add one log per every 512 current-too-low events.
Logs can be disabled if necessary:
/system logging set [find topics~"info"] topics=info,!poe-out
/system logging set [find topics~"warning"] topics=warning,!poe-outPoE-Out LEDs
Models with dependant voltage output
PoE-Out LED behaviour can differ between models, but most of them will indicate PoE-Out state on one additional LED. Devices with one voltage output will light:
- Red colour LED - PoE-Out port state is powered-on (auto or forced-on mode).
- Blinking Red colour LED - PoE-Out port state is short-circuit
Models with selectable voltage output
Models with multiple voltage options can indicate additional information:
- Green colour triangle LED - PoE-Out port state is powered-on (auto or forced-on mode), PD uses low voltage.
- Red colour triangle LED - PoE-Out port state is powered-on (auto or forced-on mode), PD uses high voltage (af/at or passive).
- Blinking Green colour triangle LED - PoE-Out port state is short-circuit or overload
- Blinking Red colour triangle LED - PoE-Out port state is short-circuit or overload
Model-specific LED behaviour
Питание сетевых устройств через Ethernet
Ни для кого не секрет, что любое сетевое устройство нуждается в источнике питания. Обычно для этой цели используется блок питания, преобразующий переменное напряжение 220В в постоянное, подходящее для питания конкретного устройства. Однако в ряде случаев подключение сетевого устройства к питающей сети бывает затруднено. Например, в случае с цифровой камерой видеонаблюдения либо wi-fi точкой доступа, расположенной вдали от источника питания.
Для этих целей и придумали технологию PoE (Power over Ethernet), которая подразумевает подачу электропитания на сетевое устройство через кабель Ethernet. При этом один и тот же кабель используется как для передачи данных, так и для питания устройства.
RouterOS
Usage
RouterOS provides an option to configure PoE-Out over Winbox, Webfig, and CLI, basic commands using the CLI are
Property Description print () Prints PoE-Out related settings. export () export is displayed under /interface ethernet menu. monitor (string| interface) Shows poe-out-status of a specified port, or all ports with /interface ethernet poe monitor [find] command. power-cycle (time:0..1m |; Default: 5s) Disables PoE-Out power for a specified period of time. Global Settings
Some MikroTik PoE-Out devices support the global PoE setting which can be configured under /interface ethernet poe settings menu. Global setting ether1-poe-in-long-cable feature disables strict input/output current monitoring (short detection) to allow the use of PoE-Out with long ethernet cables and/or avoiding improper short-circuit detection.
Property Description ether1-poe-in-long-cable (yes | no) Setting it to "yes" will disable short detection on all poe-out ports. This is potentially dangerous settings and should be used with caution Note: Global setting of ether1-poe-in-long-cable can also affect PoE-Out behavior on PSE which is powered using a DC connector
Port Settings
PoE-Out can be configured under the menu. Each port can be controlled independently.
- auto-on - the board will attempt to detect if power can be applied to the port. For powering there should be resistance in the range from 3kΩ to 26.5kΩ
- 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
Highest priority is 0, the lowest priority is 99. If there are 2 or more ports with the same priority then port with the smallest port number will have a higher priority. For example, if ether2 and ether3 have the same priority and over-current is detected then PoE-Out on ether3 will be turned off.
Note: If poe-voltage=auto and poe-out is set to "forced-on", LOW voltage will be used by default. If the PD supports only high voltage, make sure you also set poe-voltage=high when forcing the PoE output.
Power-cycle settings
RouterOS provides a possibility to monitor PD using a ping, and power-cycle a PoE-Out port when the host does not respond. power-cycle-ping feature can be enabled under /interface ethernet poe menu.
Property Description power-cycle-ping-enabled (yes | no; Default: no) Enables ping watchdog, power-cycles port if a host does not respond to ICMP or MAC-Telnet packets. power-cycle-ping-address (IPv4 | IPv6 | MAC; Default: ) An address which will be monitored. Since RouterOS 6.46beta16, an active route towards PD is required in case an IP address is configured, so make sure PSE can reach the PD. In case the MAC address is specified, PSE will send MAC-Telnet ping requests only from a specified ethernet interface. When configuring a bridge vlan-filtering or some way of VLAN switching, it is recommended to use the IP address for monitoring your PD. power-cycle-ping-timeout (time:0..1h |; Default: 5s) If the host does not respond for more than period of time, then PoE-Out port is switched off for 5s. power-cycle-interval (time| any; Default: ) Disables PoE-Out power for 5s between the specified intervals. Not related with the power-cycle-ping feature. If power-cycle is enabled, /interface ethernet poe monitor will show the actual status of the host and time when power cycle will be performed [1]
SwOS interface provides basic PoE-Out configuration options:
- PoE Out - Change between PoE-out modes (auto/on/off)
- PoE Priority - Change the Priority of port (0. 8)
- Voltage Level - Change between two voltage outputs on PoE-Out ports (auto/low/high)
Источники PoE-питания делятся на 2 категории, в зависимости от местоположения:
- end-span: источник подаёт электропитание от начала кабельной линии. В основном это сетевые коммутаторы с поддержкой PoE.
- mid-span: источник электропитания включается вразрез кабельной линии. Эти устройства называются инжекторами.
С точки зрения администратора устройства end-span удобнее, т.к. обладают большей гибкостью в управлении подключенными потребителями.
Рис.1. Возможности управления PoE-питанием на оборудовании MikroTik.
Если для подачи электропитания используются пары 1-2 и 3-6, в стандарте IEEE такая схема называется Alternative А. Использование при передаче электропитания проводников 4-5 и 7-8 — схема Alternative B. Стандарт IEEE 802.3at работает только по схеме распиновки типа B, использование типа A запрещено стандартом. При использовании Passive PoE питание подводится по проводникам 4-5 и 7-8.
Рис.2. Схемы подачи питания Alternative A и Alternative B.
Главное отличие источников питания стандарта IEEE и Passive PoE — в способе работы с питаемым устройством. Источники IEEE выполняют согласование с конечным устройством, определяя наличие поддержки PoE, необходимую подаваемую мощность, отсутствие электрических неисправностей. Источники Passive PoE не в полной мере соответствуют стандарту. Они не опрашивают питаемые устройства, поэтому их применение связано с риском повреждения оборудования - техническая совместимость устройств должна быть подтверждена документально, неисправность кабельной линии также способна повредить оборудование. Поэтому применение устройств IEEE повышает стабильность работы PoE-устройств, увеличивает совместимость и уменьшает вероятность выхода из строя оборудования.
Стандарт 802.3af предусматривает максимальную мощность потребителя до 12,95 Вт при напряжении питания 37-57 В. Стандарт 802.3at — до 25,5 Вт при напряжении питания 42,5-57 В. Т.о. максимальная мощность питаемого по PoE устройства, согласно стандарту — 25,5 Вт. Данные значения необходимо учитывать при расчёте суммарной нагрузки на PoE-коммутатор и нагрузки на каждый его порт.
Подключение по Passive PoE в основном применяется при использовании устройств одного производителя. Также возможно подключение устройств разных производителей, имеющих документированную поддержку Passive PoE и работающих на скорости 100 мбит/с (при этом для обмена данными используются пары 1-2 и 3-6).
Для успешного подключения PoE-устройств необходимо уделить внимание выбору кабеля. Жилы витой пары должны быть медные, толщиной не мене 0,51 мм (24AWG), сопротивление в жилах не более 9,38 Ом на 100 м. При соблюдении этих характеристик максимальная длина магистрали до устройства с поддержкой IEEE 802.3af/at — 90 м. При использовании Passive PoE — до 40 м.
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