---
title: "WIZ107SR vs WIZ750SR"
url: "https://maker.wiznet.io/forum/14542"
markdown_url: "https://maker.wiznet.io/forum/14542/md"
type: "Forum topic"
category: "Serial-to-Ethernet & ConfigTool"
author: "Marc"
created: "2022-05-04T08:58:18+09:00"
last_activity: "2022-05-04T08:58:18+09:00"
language: "en"
views: 346
replies: 0
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# WIZ107SR vs WIZ750SR

## Question

Asked by Marc on 2022-05-04 in Serial-to-Ethernet & ConfigTool.

Hello,

We used WIZ107 and now are replacing it with WIZ750.
It wasn’t working properly, we observed with wireshark that the WIZ750 was sending 1 byte per packet so we changed the “Time (ms)” setting in the “Serial data packing condition” section of the configuration tool to 10ms. It solved the problem.
However, please note it was not needed with WIZ107. Can you confirm it is the correct way to solve the problem ?

Besides, as we observed the TCP frame, either with WIZ107 or WIZ750, Wireshark says the TCP frames are malformed.
Can you please tell us more about that ? Please refer to the picture attached.

[![Malformed TCP Frame from WIZ750](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/7/759d9f99e5ce6f5e727f597cfb21cc070c7c7847.png) Malformed TCP Frame from WIZ7501010×586 34.6 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/7/759d9f99e5ce6f5e727f597cfb21cc070c7c7847.png)

---

Source: https://maker.wiznet.io/forum/14542