---
title: "Cable length"
url: "https://maker.wiznet.io/forum/9968"
markdown_url: "https://maker.wiznet.io/forum/9968/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "mahdavifar"
created: "2014-02-21T10:11:01+09:00"
last_activity: "2017-05-04T08:31:55+09:00"
language: "en"
views: 817
replies: 12
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Cable length

## Question

Asked by mahdavifar on 2014-02-21 in Ethernet Chips.

Hi,

What is the maximum network cable length when using W5100?
When my cable exceeds 10-12 meters the module don’t plug into network ( all LEDs are off ).

Regards

## Replies

### Reply 1 by irinakim, 2014-02-24

Hi,

I will confirm about your question.
I will contact you as soon as possible.

thanks, ![:slight_smile:](https://emoji.discourse-cdn.com/twitter/slight_smile.png?v=12)

### Reply 2 by irinakim, 2014-02-24

Hi~

We had tested about LAN cable length to below 100 meter.
Test result,W5100 has been operated without any problem. Can you test the Ping reply(from W5100)?
Do you operate Other products well when this LAN cable?

thanks ![:slight_smile:](https://emoji.discourse-cdn.com/twitter/slight_smile.png?v=12)

### Reply 3 by mahdavifar, 2014-02-25

Hi,
Cable is OK. I have tested it with my laptop.
When I connect a cable more than 10-12 meters to W5100 it is not plug at all. All Leds go off and there is no response ( even Ping test ).
any suggestion ?

Regards

### Reply 4 by irinakim, 2014-02-26

Hi,

We tested using module on the W5100. It has been operated without any problem.
Could you send me your schematic?
If you send your schematic,I’ll look over your schematic and tell you in a few days.

thanks, ![:slight_smile:](https://emoji.discourse-cdn.com/twitter/slight_smile.png?v=12)

### Reply 5 by mahdavifar, 2014-02-26

Hi,

There is schematics of Network and Power pages attached.
I would be glad if you tell me your suggestions.

Are you a member of wiznet technical team?

Regards.

[POWER.pdf](https://maker.wiznet.io/forum/legacyFile.asp?path=mVETOZDsUbRgE1QbvIrc6NwB7IQ.pdf) (15.1 KB)
[NETWORK.pdf](https://maker.wiznet.io/forum/legacyFile.asp?path=yCM8ekN3zGP41iIhyYqLHlCMvuV.pdf) (20.7 KB)

### Reply 6 by irinakim, 2014-02-26

Hi~

Could you send me the datasheet of RJ000002(J3)?
I can’t find out the datasheet.
first, I will confirm the schematic you sent me.
thanks, ![:slight_smile:](https://emoji.discourse-cdn.com/twitter/slight_smile.png?v=12)

### Reply 7 by mahdavifar, 2014-02-27

Hi,

I have used 49R9-%1 resistors too but it didn’t work. As you mentioned each pair has its own impedance, so is it right that we use same resistors for all pairs?
My main problem is about Analog ground ( GNDA ) and Digital ground ( GNDD ). Do we tie this together ? I found different schematics on wiznet site.
any suggestion about my schematic ? I use POE for my module.
The datasheet of RJ000002 is attached.

Regards.

[RJ000002.pdf](https://maker.wiznet.io/forum/legacyFile.asp?path=inHIO59yvR3Zi240GO6TaugHHHP.pdf) (98.2 KB)

### Reply 8 by peter, 2014-03-05

Have you checked power stability when exceeds 10-12meter cable?
If Your module is applied PoE, You should be use PoE module for Power stability.
It seems like there is only bridge-diode for PoE in your schematics. But I recommend to use PoE module.

### Reply 9 by mahdavifar, 2014-03-08

Hi Midnight,

So does it cause limitation on cable length ?
Regards

### Reply 10 by mahdavifar, 2014-03-08

Hi Peter,

What do you mean of POE module ?
The bridge is just for protecting circuit from fault in arranging of network cable pairs that causes of negative voltage pair.
When I use longer cable, I use POE with more voltage ( e.g. 15V adapter ). The voltage is stable.
The main problem is about data signals. It seems that data signals is so weak that can not travel over the network cable more than 10-12 meters. How can I solve this problem? As I know the network chip must be capable to detect weak signals over a 90 meters cable and inject signals so powerful that can travel over a cable in same length.
Any suggestion ?

Regards

### Reply 11 by peter, 2014-03-10

Ok, if power stability is good, it isn’t required PoE module.
The mean of PoE module is PD such as silvertel product([silvertel.com/products/poe-p … ernet.html](http://www.silvertel.com/products/poe-power-over-ethernet.html)).

### Reply 12 by mahdavifar, 2014-03-13

Hi Midnight,

What is the points on PCB? What kind of problem may occur about PCB that effects on cable length?
If it is possible give me your mail address and I will send you the PCB file.

Regards.

---

Source: https://maker.wiznet.io/forum/9968