UTP Cable max length to RB112

dawam · Wed Sep 20, 2006 6:08 pm

What the max UTP length possible

Tried 40metre intermittent problem. cannot reach RB 112

Set Ether speed to 10Mbps

Set Auto negotiate = no

Using Shielded 24AWG AMP(branded) STP cable.
Using POE .. even tried to put Mikrotik 18v Power Suppy direct on RB112 and access data on the 40m cable still problem..no problem with shorter UTP.

Conclusion not power problem.. data signal problem.
Interface Ethernet Monitor - link is ok

Any experience, help appreciated

HarvSki · Wed Sep 20, 2006 6:23 pm

Each ethernet segment can be 100m, I've deployed 110m lengths but then had trouble getting PoE to work but not data. PoE standard also works to 100m but I think you will need to use 48v power supply

dawam · Wed Sep 20, 2006 6:31 pm

HarvSki,
Thanks for sharing.

100m, that's what I thought..

I am using Dlink 48V 400ma POE .

Like I mention , I did even plug in direct the Mikrotik 18V supply direct to the RB power inlet and access the data thru the 40m UTP still problem.

I have been trying to shorted the cable path till I get slightly below 40m then I could access the RB board.

I have got another RB slightly above 50m, I still have problem accessing it.. not problem with shorter UTP

sten · Wed Sep 20, 2006 6:38 pm

which standards are you following?

dawam · Wed Sep 20, 2006 6:42 pm

Sten,

what did you mean??

HarvSki · Wed Sep 20, 2006 6:49 pm

which standards are you following?

ooo sten you are such a perfectionist!

I follow the put enough volts in one end and hope enough comes out the other standard

I suppose you could get yourself off to sleep with IEEE 802.3

dawam · Wed Sep 20, 2006 7:13 pm

Was searching for Rb112 spec.

Ya , the RB112 spec did mention

" boards are compliant with IEEE802.3af Power over Ethernet standard (except power over datalines) and accept 48V powering over up to 100m (330 ft) long Ethernet cable connected to the Ethernet port (J5 or J6)."

I can connect with shorter (< 40m) POE cable , so my POE should be OK.
But then again straight supply to power input and long POE won't work.

I am using CAT5e STP cable

There is also a mention

" In case it is planned to power the board up from a
standard 48V DC PoE injector (note that the RouterBOARD
does not support power over datalines), the JP2 jumper
should be opened."

Maybe I should try this tomorrow. Need to look for the JP2 jumper..

Anyone have tried the need to remove this jumper before.

sten · Thu Sep 21, 2006 4:08 am

which standards are you following?
ooo sten you are such a perfectionist!

I follow the put enough volts in one end and hope enough comes out the other standard

I suppose you could get yourself off to sleep with IEEE 802.3

Haha!
IEEE802.3 is ethernet not cables, silly!

How many volts are the data lines running at and what happens with the energy lost from the PoE lines? Disappear? *sniggers*

jo2jo · Thu Sep 21, 2006 4:55 am

the energy is destroyed

on a serious note; i've send 18v PoE across 200ft to a Pac Wireless PoE breakout box (great little 20$ device that lets u power ANYTHING within PoE's power margins)

Stryker777 · Thu Sep 21, 2006 5:53 am

My first guess would be that your cable either has a pinch in it or a bad connector crimp. 40m is easy to get data and poe across. Try with another cable just sitting there coiled up in front of you.

UTP Cable max length to RB112

UTP Cable max length to RB112

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