---
title: "ESP32s3 and read phy error"
url: "https://maker.wiznet.io/forum/14896"
markdown_url: "https://maker.wiznet.io/forum/14896/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "WAVEWT"
created: "2023-05-02T07:19:08+09:00"
last_activity: "2023-05-03T00:22:54+09:00"
language: "en"
views: 293
replies: 2
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# ESP32s3 and read phy error

## Question

Asked by WAVEWT on 2023-05-02 in Ethernet Chips.

Hello

I’m implementing MODBUS TCP by using ESP32s3 and W5500.

I could see this error after starting MODBUS TCP few hours.

I used code from ESP32s3 IDF examples.

E (9504067) w5500.mac: emac_w5500_read_phy_reg(335): read PHY register failed
E (9504067) w5500.phy: w5500_update_link_duplex_speed(69): read PHYCFG failed
[E (9504067) w5500.phy: w5500_get_link(112): update link duplex speed failed

Could I know why this error is happend?
Is there any idea about debugging and solving problem?

Thanks

## Replies

### Reply 1 by Eugeny, 2023-05-02

Look [here](https://github.com/espressif/esp-idf/issues/11295), sounds like a bug. Tracking code led me [here](https://sourcegraph.com/github.com/espressif/esp-idf/-/blob/components/esp_eth/src/esp_eth.c?L76), and I can’t proceed further because I do not have reference to W5500 libraries you use. In general you must identify what routine fails in W5500 driver and see the cause.

### Reply 2 by WAVEWT, 2023-05-03 (in reply to reply 1)

Thanks for your help!

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Source: https://maker.wiznet.io/forum/14896