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Hi there

Can the TRB245 actually be powered off passive POE?

I have made a custom cable per the instructions on the manual page, I supply the blue pair +24v and brown pair 0v - but that didnt work

So i tried to use a ubiquiti POE injector that i always use with my RUT950, this also didnt work on the TRB245

Is there something i am missing? I am getting nothing over POE but the included power supply into the terminal block works fine
Sorry, far from an answer; but a me too...  I've tried a few poe injectors, and an output from a Mikrotik (Hex s) which supports passive poe in the same format as the TRB245 - but nothing works.

3 Answers

0 votes

I see the passive POE powering option has since been removed the Wiki page

Best answer
0 votes

Thank you for contacting .

TRB245 can only be powered up over 4 PIN connector.

Further details could be seen here:

If you see the data sheet there is only 1 powering option for TRB245.

You can see for Rut955 we have information here for passive POE as its supporting Passive POE.

Also you can see in the data sheet , Power:

Always check our wiki page and data sheets for any such information or configuration examples related material.

Because such action can sometimes damage device.

I hope it helps.

If you any queries in future please revert back .



+1 vote

Teltonika (& many other suppliers) often don't explain well what they mean by PoE creating confusion. Mainly around the use of the term "PoE", ie in a "generic sense" vs PoE in the official sense ie to the 802.3at/af IEEE standards. Further, there is also a need to explain if a device provides power or needs power. For example, an Ethernet Switch such as TSW-100 is technically referred to as PoE-PSE (Power Sourcing Equipment)  ie it supplies PoE Power to PD's. And a device that accepts PoE Power from a switch or Injector is called a PoE-PD (Powered Device), such as VoIP telephones, IP Cameras and some routers. Not using the correct suffix leaves the question open as to what is the device can do.  be aware that TSW-100 will require external 48V dc Power in order for it to work as PoE-PSE to the standard. If you power it with a lower voltage eg 12V it may still supply power but no longer the  PoE standard - but will work to the Passive mode. 

Passive PoE, the type of PoE that is supported on some of the Teltonika devices, is non-standard ie a proprietary version of PoE...So a TRB140 is sort of a PoE-PD but not to the standard. Passive PoE just means that the spare pairs (4,7 & 5,8) in the RJ45/CAT5/6 connector can be used for getting DC power into the device and pins internally are wired in parallel with the external DC supply pins so you have the option of supplying the same dc power via either RJ45 or external connector or potentially both. The actual voltage will vary with each device type, eg the TRB 140 can have 9-24Vdc on those pins see following; 

PoE (802.3at,etc) works on sending 48V on those same unused pairs. Passive operating voltages can be random and will vary with each OEM. 

PoE Switches and Injectors can often do other clever stuff like detecting if the PoE-PD device supports PoE at all - if it detects it doesn't then it won't supply power thus preventing potential damage to the device. More sophisticated PSE (typically on a managed ethernet switch) can turn the power on and off remotely to a specific port which can be very handy to do reboots tec. 

Hope this helps. 


We often make up a 3-way cable that splits out DC Power Feed and Comms at one end and the regular RJ45 at the other that connects to the TRB's saving the need for running extra dc power cable.  

Great answer thanks, as i mentioned Ubiquiti actually uses the same passive POE standard of 24v as many of the teltonika products, so that equipment is usually very compatible