---
title: "About detection method of disconnection LAN cable"
url: "https://maker.wiznet.io/forum/11081"
markdown_url: "https://maker.wiznet.io/forum/11081/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Atsu"
created: "2015-06-01T05:42:35+09:00"
last_activity: "2017-05-04T08:35:50+09:00"
language: "en"
views: 1207
replies: 3
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# About detection method of disconnection LAN cable

## Question

Asked by Atsu on 2015-06-01 in Ethernet Chips.

Hi all,

I want to detect by uC whether LAN cable is disconnect via W5100 TCP/IP.
I use W5100 as a server.

Thank you.
Atsu

## Replies

### Reply 1 by Coccoliso, 2015-06-01

hi,
I checked the specifications and unlike other chip (like the W5200) that did not have the PHY link status register so you can not do this test.

### Reply 2 by Atsu, 2015-06-03

Hi Coccoliso,

Thank you for your reply.
I got it. ![:slight_smile:](https://emoji.discourse-cdn.com/twitter/slight_smile.png?v=12)
So I will check disconnection cable by transmission tame out.

Atsu

### Reply 3 by Coccoliso, 2015-06-03

If you have an home made card can use pin 66 even if:
Link LED : Active low in link state indicates a good status for 10/100M. It is always ON when the link is OK and it flashes while in a TX or RX state.  then flashes when communicating … I saw that an arduino library uses a GPIO to read this state then someone has already tried with success.

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Source: https://maker.wiznet.io/forum/11081