获取设备连接（第四步)
# Get device connection
**Brief description**：
- If you want to call the business interface, you need to obtain a device connection wcid
- wcid It is permanently valid and associated with the device. If the device connection is called multiple times, only the last WCID is valid。
**request URL**：
- {APIURL}/dy/device/get_device_conn
- Access-Token
**Request mode**
- POST
**Request header Headers**
- Content-Type：multipart/form-data
**parameter**：
|Parameter name | required | type | description
|-|-|-|-|
|device_id|是|string| device_id
**Return data**：
|Parameter name | type | description|
|-|-|-|
|code|int|0 success, -1 failure 1 prompt message|
|msg|string|feedback information|
|data|string| wcid Value, which needs to be saved locally, and device_ ID binding|
**Request parameter example**
```
{
"device_id": "123232323"
}
```
** Return **
```
{
"code": 0,
"data": "1111111111",
"msg": "success"
}
```
**Error return example**
```{
"msg": "Call failed",
"code": -1,
"data": null
}
```