---
title: "WIZ107SR Occasional Lost Data (Serial -> TCP)"
url: "https://maker.wiznet.io/forum/9979"
markdown_url: "https://maker.wiznet.io/forum/9979/md"
type: "Forum topic"
category: "Serial-to-Ethernet & ConfigTool"
author: "JLCJoe"
created: "2014-02-25T02:39:06+09:00"
last_activity: "2017-05-04T08:31:46+09:00"
language: "en"
views: 464
replies: 0
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# WIZ107SR Occasional Lost Data (Serial -> TCP)

## Question

Asked by JLCJoe on 2014-02-25 in Serial-to-Ethernet & ConfigTool.

Hello,

We have been using the WIZ107SR (and WIZ108SR) for quite some time and are have been quite happy with it. We are using it in a control panel with switches, encoders, LEDs and LCDs for a bidirectional data link to a host computer.

Unfortunately, we have received a report from a customer that is experiencing occasional lost bytes.

Here is a sample of the data exchange between the serial side and the ethernet side of the WIZ107SR. Each line is a separate TCP Packet:

Serial → Ethernet 80 00 0d f7
Ethernet → Serial f0 15 31 04 01 0d f7
Ethernet → Serial f0 15 31 02 02 b4 00 ef 1f 00 01 f7
Ethernet → Serial f0 15 31 02 03 b5 01 ee 1e 01 00 f7
Ethernet → Serial f0 15 31 01 02 b7 08 01 00 31 20 30 30 30 31 f7
Ethernet → Serial f0 15 31 02 02 b4 20 ef 3f 00 01 f7
Ethernet → Serial f0 15 31 02 03 b5 21 ee 3e 01 00 f7
Ethernet → Serial f0 15 31 01 02 b7 28 01 00 31 20 30 30 30 31 f7
Ethernet → Serial f0 15 31 02 02 b4 40 ef 5f 00 01 f7
Ethernet → Serial f0 15 31 02 03 b5 41 ee 5e 01 00 f7
Ethernet → Serial f0 15 31 01 02 b7 48 01 00 31 20 30 30 30 31 f7
Ethernet → Serial f0 15 31 02 02 b4 60 ef 7f 00 01 f7
Ethernet → Serial f0 15 31 02 03 b5 61 ee 7e 01 00 f7
Ethernet → Serial f0 15 31 01 02 b7 68 01 00 31 20 30 30 30 31 f7
Serial → Ethernet 80 0c f7
Serial → Ethernet 80 00 0b f7
Serial → Ethernet 80 00 0a f7

Looking on the serial side, the data coming into the serial side of the WIZ107SR is:
Serial → Ethernet 80 [color=#FF0000]00[/color] 0c f7
Serial → Ethernet 80 00 0b f7
Serial → Ethernet 80 00 0a f7

The byte 00 highlighted in red is missing from the TCP packet.
This does nor occur if I do not send Ethernet → Serial data.
This issue occurs on multiple WIZ107SR modules.

I am using:
WIZ107SR Rev 1.1
Firmware 2.20
TCP Server Mode
Debug Message Output disabled
Baud Rate = 115200
Data bits = 8
Parity = odd
Stop bits = 1
Flow Control = none
Timer = 10
Size = 0
Character = F7 (this is the end of our command, we use this to trigger new TCP packet)
Inactivity Timer = 0

Is there anything we can do to prevent this behavior from occurring?
Thanks in advance.

---

Source: https://maker.wiznet.io/forum/9979