---
title: "WIZ750SR-100 TCP GPIO control"
url: "https://maker.wiznet.io/forum/13730"
markdown_url: "https://maker.wiznet.io/forum/13730/md"
type: "Forum topic"
category: "Serial-to-Ethernet & ConfigTool"
author: "jmiguelg"
created: "2020-03-05T11:29:04+09:00"
last_activity: "2020-04-17T14:40:42+09:00"
language: "en"
views: 650
replies: 2
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# WIZ750SR-100 TCP GPIO control

## Question

Asked by jmiguelg on 2020-03-05 in Serial-to-Ethernet & ConfigTool.

Dear Sir or Madam,

I try to change the state of GPIOA of my WIZ750SR-100 board through TCP but the PIN does not change state.

I open TCP connection to: 192.168.11.2 and port: 50001

I check the MAC:
SENT: {4D}{41}{FF}{FF}{FF}{0D}{0A}{50}{57}{20}{0D}{0A}{4C}{49}{0D}{0A}
RECEIVED:{4D}{41}{00}{08}{DC}{56}{53}{FF}{0D}{0A}{50}{57}{20}{0D}{0A}{4C}{49}{31}{39}{32}{2E}{31}{36}{38}{2E}{31}{31}{2E}{32}{0D}{0A}

which means my MAC is: {00}{08}{DC}{56}{53}{FF}

after that I want to set GPIO A as output:
SENT: {4D}{41}{00}{08}{DC}{56}{53}{FF}{0D}{0A}{50}{57}{20}{0D}{0A}{43}{41}{31}{0D}{0A}
RECEIVED: {4D}{41}{00}{08}{DC}{56}{53}{FF}{0D}{0A}{50}{57}{20}{0D}{0A}
Is that answer ok?

After that I want to set GPIO A HIGH:
SENT: {4D}{41}{00}{08}{DC}{56}{53}{FF}{0D}{0A}{50}{57}{20}{0D}{0A}{47}{41}{31}{0D}{0A}
RECEIVED:{4D}{41}{00}{08}{DC}{56}{53}{FF}{0D}{0A}{50}{57}{20}{0D}{0A}

But the PIN does not change state. It changes nothing (GPIOA remains LOW).
Should the answers be different? Am I doing something wrong?

Regards,

## Replies

### Reply 1 by becky, 2020-03-06

Hello,

I tested it.

Set GPIOA to HIGH
SENT :
![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/c/cb090a90e7aacbbc83f7c13004f5b9c8bc4a1ce2.png)

RECEIVED:
![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/4/4857d727ba50c4c955897513390dbfd6fb4787de.png)

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/3/3baee731ffda65147d23b19799f11fa62d270608.jpeg) image720×960 566 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/3/3baee731ffda65147d23b19799f11fa62d270608.jpeg)

Set GPIO A to low
SENT :
![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/c/c595ee4932f799635ca38d5f530eb215cd828d4c.png)

RECEIVED:
![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/8/80ee2b325bb32d01e1b55edef77e206ec6b7d628.png)

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/5/584675e6a3adf4a376d1cd86e6b1a31ac3f02b59.jpeg) image720×960 526 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/5/584675e6a3adf4a376d1cd86e6b1a31ac3f02b59.jpeg)

It worked.
So I hope you check the GPIOA pin once more.

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/a/a44e378b4bc625d7e9f541e01690044aa43a0ed7.png) image905×755 445 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/a/a44e378b4bc625d7e9f541e01690044aa43a0ed7.png)

### Reply 2 by jmiguelg, 2020-04-17 (in reply to reply 1)

Hello becky

My MAC info was wrong. After setting the right MAC in the order it worked.

Thank you for your reply.

---

Source: https://maker.wiznet.io/forum/13730