> For the complete documentation index, see [llms.txt](https://freeioe.gitbook.io/doc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://freeioe.gitbook.io/doc/reference/app/port/helper.md).

# 帮助模块

***

## 应用通讯端口帮助函数模块

本模块封装一些有助与使用通讯端口的函数。帮助用户快速开发FreeIOE应用。

[使用参考](https://github.com/freeioe/freeioe_example_apps/blob/master/example/serial_socket/app.lua)

## 成员函数

### read\_socket

读取套接字数据。

```lua
function _M.read_socket(sock, len, dump)
end
```

#### 参数说明

* sock socket对象 (socketchannel的request中response函数传入的socket对象)
* len 数据长度
* dump 报文输出回调函数 function(string\_data)

#### 返回值

读取成功则读到的数据，否则返回nil

### read\_serial

读取串口数据。

```lua
function _M.read_serial(serial, len, dump, timeout)
end
```

#### 参数说明

* serial serial对象 (serialchannel的request中response函数传入的serial对象)
* len 数据长度
* dump 报文输出回调函数 `function(string_data)`
* timeout 读取超时，单位是ms。默认是3000ms

#### 返回值

读取成功则读到的数据，否则返回nil


---

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