3.1.6 PING
==========

作者：闫俊杰 ## 语法规则： \| 命令类型 \| 语法 \| 返回和说明 \| \| ————
\| ———— \| ———— \| \| 设置命令 \|
AT+CIPPING=<IPaddr>[,<retryNum>[,<dataLen>[,<timeout>[, <ttl>]]]] \|
+CIPPING:<replyId>,<IpAddress>,<replyTime>,<ttl>[<CR><LF>
+CIPPING:<replyId>,<Ip Address>,<replyTime>,<ttl> […]]OK \| \| 查询命令
\|AT+CIPPING? \| +CIPPING: <retryNum>,<dataLen>,<timeout>,<ttl>OK \| \|
测试命令 \| AT+CIPPING=? \|+CIPPING: (list of supported
<retryNum>s),(list of supported <dataLen>s),(list of supported
<timeout>s),(list of supported <ttl>s) OK \|

注意事项
--------

-  发送 PING 命令之前，需激活 GPRS PDP 上下文。
-  当发送 PING 到时无回应，那么返回的信息则显示<replyTime>=600
   并且<ttl>=255。
-  执行本命令时，如果 GPRS PDP
   上下文由于某种原因被去激活了，例如掉网，那么本命令立即终止 执行。

参数定义
--------

+--------------+----------------------------+--------+--------------+
| 参数         | 定义                       | 取值   | 对取值的说明 |
+==============+============================+========+==============+
| <IPaddr>     | PING的目标服务             |        |              |
|              | 器地址。IP地址或域名都支持 |        |              |
+--------------+----------------------------+--------+--------------+
| <retryNum>   | 需要发送的PING的数量       | 1-100  | 缺省值:4     |
+--------------+----------------------------+--------+--------------+
| <dataLen>    | PING请求的长度             | 0-1024 | 缺省值:32    |
+--------------+----------------------------+--------+--------------+
| <timeout>    | The timeout waiting for a  | 1-600  | 单位：100 ms |
|              | single Echo Reply          |        |              |
+--------------+----------------------------+--------+--------------+
| <ttl>        | time to live               | 1-255  | 缺省值:64    |
+--------------+----------------------------+--------+--------------+
| <replyId>    | Echo Reply serial number   |        |              |
+--------------+----------------------------+--------+--------------+
| <Ip Address> | IP Address of the remote   |        |              |
|              | host                       |        |              |
+--------------+----------------------------+--------+--------------+
| <replyTime>  | time to receive the        |        | 单位：ms     |
|              | response                   |        |              |
+--------------+----------------------------+--------+--------------+

使用示例
--------

::

    发→◇AT+CSTT
    收←◆OK
    发→◇AT+CIICR
    收←◆OK
    发→◇AT+CIFSR
    收←◆10.11.142.75
    发→◇AT+CIPPING="www.baidu.com"
    收←◆+CIPPING: 1,"183.232.231.174",120,53
          +CIPPING: 2,"183.232.231.174",100,53
          +CIPPING: 3,"183.232.231.174",100,53
          +CIPPING: 4,"183.232.231.174",100,53