Espressif ESP32 At Instruction Set page 30

!
Parameters
Example
Set
Command
Response
Parameters
Notes
Example
Espressif
<link ID>: ID of network connection (0~4), used for multiple connections.
•
<type>: string parameter indicating the connection type: "TCP", "UDP" or "SSL".
•
<remote IP>: string parameter indicating the remote IP address.
•
<remote port>: remote port number.
•
[<TCP keep alive>]: detection time interval when TCP is kept alive; this function is disabled by
•
default.
‣ 0: disable the TCP keep-alive function.
‣ 1 ~ 7200: detection time interval, unit: second (s).
⚠ Notice:
To use <UDP mode> , <UDP local port> must be set first.
AT+CIPSTART="UDP","192.168.101.110",1000,1002,2
For more information please see Chapter 7: AT Command Examples.
AT+CIPSTART=[<link ID>,]<type>,<remote IP>,<remote port>[,<TCP keep alive>]
OK
or
ERROR
If TCP is already connected, the response is:
ALREADY CONNECT
<link ID>: ID of network connection (0~4), used for multiple connections.
•
<type>: string parameter indicating the connection type: "TCP", "UDP" or "SSL".
•
<remote IP>: string parameter indicating the remote IP address.
•
<remote port>: the remote port number.
•
[<TCP keep alive>]: detection time interval when TCP is kept alive; this function is disabled by
•
default.
‣ 0: disable the TCP keep-alive function.
‣ 1 ~ 7200: detection time interval, unit: second (s).
ESP32 can only set one SSL connection at most.
•
• SSL connection does not support UART-Wi-Fi passthrough mode (transparent transmission).
SSL connection needs a large amount of memory; otherwise, it may cause system reboot.
•
AT+CIPSTART="SSL","iot.espressif.cn",8443
Establish SSL Connection
25 53 ! /!
5. TCP/IP-Related AT Commands
2017.02