---
title: "About WIZ550S2E-Modbus project on github"
url: "https://maker.wiznet.io/forum/15076"
markdown_url: "https://maker.wiznet.io/forum/15076/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Bohu-Tang"
created: "2023-11-23T09:05:01+09:00"
last_activity: "2023-12-12T09:19:38+09:00"
language: "en"
views: 174
replies: 7
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# About WIZ550S2E-Modbus project on github

## Question

Asked by Bohu-Tang on 2023-11-23 in Ethernet Chips.

Dear all
On github this WIZ550S2E-Modbus project, there is no function code processing function?

[![1](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/1/18e788723a5ddc5cfa10d84f343496a42252adc8.png) 11014×1728 72 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/1/18e788723a5ddc5cfa10d84f343496a42252adc8.png)

## Replies

### Reply 1 by austin, 2023-11-27

Hello [@Bohu-Tang](https://maker.wiznet.io/u/bohu-tang)

What does function code processing function mean?

Do you mean the function code processing function to find the function as shown in the picture below?

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/5/5f331e18480b256c588f52793284e48af0e43cbb.png) image1282×722 149 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/5/5f331e18480b256c588f52793284e48af0e43cbb.png)

### Reply 2 by Bohu-Tang, 2023-11-27 (in reply to reply 1)

Hi austin
Thanks for your answer.I am looking for a Modbus-TCP protocol function code handler, such as function code 03,04,06,10, but I can’t find it in this project. Am I find in the wrong place?

[![1](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/2/2655ef8b38d007f7a7e4e9b879ffd160eb6763a2.png) 1841×1132 306 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/2/2655ef8b38d007f7a7e4e9b879ffd160eb6763a2.png)

### Reply 3 by Bohu-Tang, 2023-11-27 (in reply to reply 1)

Hi austin
I came up with a way to use the mbtcpcpppackage function to write a switch() function after the if(usPID==MB_TCP_PROTOCOL_ID) function to determine the corresponding function code, and then enter the corresponding function code. I don’t know if that’s possible, because this function is static bool.

[![1](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/1/1518ebc1605eeb2737131d1cb7e74cefaee7c678.png) 11074×1846 103 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/1/1518ebc1605eeb2737131d1cb7e74cefaee7c678.png)

### Reply 4 by Bohu-Tang, 2023-11-27 (in reply to reply 1)

Such as this. This function is to judge the function code of Modbus-RTU.But I think it should be the same for Modbus-TCP.if(usPID==MB_TCP_PROTOCOL_ID), it indicates that Modbus-TCP has been identified, and you can check the function code. I don’t know if my logic is right. If you have any questions, please give me your suggestions.

[![2](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/4/4495f87175c0bf2209e4e5abf70d7f36e81bb277.png) 21667×767 55.5 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/4/4495f87175c0bf2209e4e5abf70d7f36e81bb277.png)

### Reply 5 by Bohu-Tang, 2023-11-28

Hi austin
Can you help me with the question？

### Reply 6 by austin, 2023-11-28

Hi [@Bohu-Tang](https://maker.wiznet.io/u/bohu-tang)

If you need any functions, you can add them and use them.

If you need the function code processing function I think it would be okay to add it after the ‘if( usPID == MB_TCP_PROTOCOL_ID )’ conditional statement as mentioned above.

### Reply 7 by Bohu-Tang, 2023-11-28 (in reply to reply 6)

Thanks a lot for your answer.

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Source: https://maker.wiznet.io/forum/15076