---
title: "SEND does or doesn't send all data?"
url: "https://maker.wiznet.io/forum/13913"
markdown_url: "https://maker.wiznet.io/forum/13913/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "essele"
created: "2020-06-30T13:44:29+09:00"
last_activity: "2020-07-06T08:29:17+09:00"
language: "en"
views: 355
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# SEND does or doesn't send all data?

## Question

Asked by essele on 2020-06-30 in Ethernet Chips.

Hi,

I’m new to these devices, but have a W5500 working nicely with a PSoC microcontroller using my own library (which is very much optimised for RAM efficiency, so I can’t really use the standard library.)

One question I have though is that the data sheet for the W5500 implies that the SEND command will send all the of the data, whereas the wiki page…

<https://wizwiki.net/wiki/doku.php/products:w5500:application:tcp_function>

… calls out the fact that not all the data might be sent and I should see how much has gone and re-send if necessary.

BUT … when I look at the provided library I see that it doesn’t do that, it just waits for SEND_OK and then continues. (There is some code that seems to do this, but only for the 5200.)

So … does the SEND command for the W5500 send all of the data or not?

Thanks.

Lee.

## Replies

### Reply 1 by bangbh, 2020-07-06

![](https://avatars.discourse-cdn.com/v4/letter/e/97f17d/48.png) essele:

> So … does the SEND command for the W5500 send all of the data or not?

Send command does send all data in the buffer.

Thanks.

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Source: https://maker.wiznet.io/forum/13913