---
title: "[W7500S2E] TCP Connection is not established"
url: "https://maker.wiznet.io/forum/6768"
markdown_url: "https://maker.wiznet.io/forum/6768/md"
type: "Forum topic"
category: "General"
author: "WIZnet"
created: "2019-11-22T01:03:50+09:00"
last_activity: "2019-11-22T01:03:50+09:00"
language: "en"
views: 720
replies: 0
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# [W7500S2E] TCP Connection is not established

## Question

Asked by WIZnet on 2019-11-22 in General.

If you have a symptom that the ping test works fine, but only the TCP connection fails, check the Transmission mode.

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/8/864b11ac5e627c0912e66b1bad63634d2a9c0410.png) image678×501 40.2 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/8/864b11ac5e627c0912e66b1bad63634d2a9c0410.png)

Transmission mode is not AT Command mode, it must be Data mode.
You can change this in the Advanced Options tab.

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Source: https://maker.wiznet.io/forum/6768