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WiFly Command Reference, Advanced Features & Applications User’s Guide 4.3.4 Using the Backup IP Address/Connect Function The module contains a feature for auto-retry and redundancy. If the host’s first IP address connection fails, the module uses the backup IP (if set). If this fails (or is not set), the module uses the first DNS name. If this fails (or is not set), the module uses the backup DNS name (if set). EXAMPLE 4-8: SET THE BACKUP IP ADDRESS set ip backup <address> // Set the backup IP address EXAMPLE 4-9: SET THE BACKUP DNS NAME set dns backup <string> // Set the backup host name 4.4 USING THE HTML CLIENT FEATURE The module has a built-in HTML client. When enabled, the module can get or post data to a web server. For example, you can use the HTML client to post serial and/or sensor data to the host web server. This feature makes possible to provide Wi-Fi capabilities to applications such as GPS units, remote sensors, weather stations, etc. 4.4.1 Retrieve Web Server Data In this example, you want to retrieve data from the web server with the format: http://www.webserver.com/ob.php?obvar=WEATHER To perform this function, use the following settings: set ip proto 18 set dns name www.webserver.com set ip address 0 set ip remote 80 set com remote 0 // Enable the HTML client // Set the web server name // Turn on DNS // Set the web server port, 80 is standard // Turn off the REMOTE string so that it // does not interfere with the post To make the connection, use the open command or you can use open www.webserver.com 80. The user’s microprocessor writes the following string to the UART: GET /ob.php?obvar=WEATHER \n\n Where the \n is the linefeed character (decimal 10 or hex 0xa). Two linefeeds are required for the web server to know the page is complete. Note: DS50002230A-page 74 Some web servers require a carriage return and linefeed to indication the page is complete. In this case, use \r\n at the end of the string instead of \n\n. 2014 Microchip Technology Inc.