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RL-ARM User's Guide (MDK v4)

RL-RTX RL-FlashFS RL-TCPnet TCP Socket Opening TCP Connection TCP Active Open TCP Passive Open Sending TCP Data Example for Sending Data Multiple TCP Connections UDP Socket Opening UDP Connection Sending UDP Data When DHCP Enabled When ARP Cache Empty Example for Sending Data IP Multicasting Multiple UDP Connections Configuring RL-TCPnet Static Configuration System Definitions Ethernet Network Interface PPP Network Interface SLIP Network Interface UDP Socket TCP Socket BSD Socket HTTP Server Telnet Server TFTP Server TFTP Client FTP Server FTP Client DNS Client SMTP Client SNMP Agent SNTP Client Error Function Runtime Configuration Library Files Using RL-TCPnet Stand Alone With RTX Kernel Event Driven Operation IP Address Assignment Ethernet Interface PPP Interface SLIP Interface Localhost Applications HTTP Server Script Language CGI Functions Ajax Support Using XML XML Example How it works SOAP Support SOAP Interface Large POST Messages Web Pages Default Page Error Pages Web on SD Card Web Update File System Interface Http Caching How it works Internal Web External Web Multi-user Authentication Using RAM File System FCARM File Converter PRINT Directive NOPRINT Directive PAGEWIDTH Directive PAGELENGTH Directive ROOT Directive Telnet Server Command Line Interface Multi-user Authentication Sending Reply Message Short Reply Long Reply Continuous Screen Update TFTP Server File System Interface TFTP Client File System Interface FTP Server File System Interface Multi-user Authentication Supported Commands FTP Client File System Interface SMTP Client SNMP Agent MIB Database MIB Interface MIB Entry MIB Table DNS Resolver Starting DNS Device Drivers Ethernet Driver Interrupt Mode Modem Driver Serial Driver Using Serial Link Cable Connection Modem Connection Windows Dial-up Add Direct Serial Link New Dial-up Connection Configure PPP Dial-up Configure SLIP Dial-up Debugging Enabling Debug Debug Level Redirecting Output Function Overview BSD Routines CGI Routines Ethernet Routines FTP Routines HTTP Routines IGMP Routines Miscellaneous Routines Modem Routines PPP Routines Serial Routines SLIP Routines SMTP Routines SNMP Routines System Functions TCP Routines Telnet Routines TFTP Routines UDP Routines RL-CAN RL-USB Example Programs Library Reference Appendix

XML Example

Here is an example of a XML web page update written in the script language. This web page displays the value of analog input (AD). When first opened, a complete AD web page is generated by the Embedded web server. Later, when you enable the periodic update of the page, this page is updated with Java Script function updateMultiple(). This function is in xml_http.js file.

  • The script file ad.cgx contains the following:
    t <form>
    t <text>
    t <id>ad_value</id>
    c x<value>0x%03X</value>
    t </text>
    t </form>
  • The script interpreter processess this file and generates the following response:
    The XML response does not contain any spaces or CR-LF characters between the XML tags.
  • The Java Script function periodicUpdateAd() activates the periodic timeouts for the page update. This function is specific for AD page module and is included in ad.cgi script file:
    function periodicUpdateAd() {
      if(document.getElementById("adChkBox").checked == true) {
        ad_elTime = setTimeout(periodicUpdateAd, formUpdate.period);
  • The update interval and url are defined in the formUpdate object. When update interval expires, an xml response is requested from the url specified in this java object.
    var formUpdate = new periodicObj("ad.cgx", 500);
  • The actual update of the analog bar and AD values on the web page is done by the java function plotADGraph():
    function plotADGraph() {
      adVal = document.getElementById("ad_value").value;
      numVal = parseInt(adVal, 16);
      voltsVal = (3.3*numVal)/1024;
      tableSize = (numVal*100/1024);
      document.getElementById("ad_table").style.width = (tableSize + '%');
      document.getElementById("ad_volts").value = (voltsVal.toFixed(3) + ' V');
    This function is called as a call-back function from the updateMultiple() java function.


  • The XML script files use the reserved filename extension cgx. Using the cgx file extension for XML script files is mandatory for the Web Server script interpreter to recognize and process the XML script files.
  • There must be no spaces or CR-LF characters between XML tags, or some web browsers might have problems when parsing the XML response.
  • The script line length is limited to 120 characters.
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