Trying to power the arduino using passive spliters in the ethernet connector and ws5100 shield

Projects General Guidance
1

Hi,

I have an arduino comunicating well with a web server using a WS5100 Ethernet shield.
My problem is, when I try to power the arduino using a Poe injector and a passive spliter on the arduino side the comunication dont works. The power works fine but no comunication. The rj45 conector only have 4 lines is a problem? Does someone knows what can cause the lack of comuinication?
Is nedeed more information about my project to to get some help?
Thanks in advance for any kind of help.
Antonio Teixeira

2

Sure it is:

PoE relies on pins 1, 2, 3, and 6 for power transmission in Mode A pinouts. For Mode B, pins 4, 5, 7, and 8 handle power delivery instead. Data transmission occurs over the other spare pins.

Source:
PoE Pinout: Enhance Your Network.

3

Which Arduino are you using?
How much voltage is connected to the injector?

4

What I tried to say is that in the passive spliter the rj45 only keep 4 lines in the rj45. The other 4 lines are conected in the power connector.

5

Hi Jim,

I am using Arduino UNO R4 Minima and the voltage is 12V. The power is working fine. Only no comunication,

6

That is OK

To do some debugging, power the R4 via USB and remove the injector but leave the splitter connected and see if it works. If it does then you know there is something wrong with the injector.
If it does not work then put the injector back in and remove the splitter and test again.

7

Powered by an external source, and keeping the spliter the communication works. Maybe the injector is not working?
But I have another cable, with spliters on both sides one for injecting the power and on the other side to grab the power and is not working too (the comunication) . I am realy confused.

8

There wer several versions of that shield, some had POE modules on them. Does your shield have POE module?

9

As far as I know Arduino dont produce anymore shields ethernet with POE. Mine is a WS5100 and sont have POE.

My conections are:

SWITCH ---------- Injector --------------SPLITTER ---------- Arduino + Shield
POWER ------------| |------------------Arduino Power

10

Maybe the injector did not follow the standard practice for POE wiring. As you know, 4 of the wires are used for power and 4 for signals. Maybe the injector has them backwards.
Otherwise, I can't explain why it does not work.

11

I believe in that but what about my cable with spliters and no injector?Shouldn work?
Is powered on 2 lines after the switch and then splited when the cable arrives to the arduino. Maybe I will buy another injector to run more tests.
Thank you Jim.

12

Sorry for the late reply.
I'm not sure that work work.

I'm far from being an expert in this area but if you are using a crossover cable and not a straight through cable it probably won't work.

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13

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