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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

BSD Socket

The BSD Socket API is a programming interface, which implements standard Berkeley Socket communication interface. These APIs are not a complete implementation of the BSD API.

The following BSD options are configurable:

  • BSD Sockets switch enables or disables the BSD Socket service in your application. It is enabled when this value is set to 1. It should be set to 0 when the BSD connections are not used.
    #define BSD_ENABLE     1
  • Number of BSD Sockets specifies the number of available BSD sockets. This number is usually set to the maximum number of simultaneously opened connections.
    #define BSD_NUMSOCKS   5
  • Number of Streaming Server Sockets specifies the number of streaming (TCP) server sockets. The server sockets listen for an incoming connection from the client.
    #define BSD_SRVSOCKS   1
  • Receive Timeout in seconds is the timeout, after which the receiving socket returns in blocking mode. A value of 0 disables the receive timeout.
    #define BSD_RCVTOUT    20
  • Hostname Resolver switch enables or disables the Host Name Resolver (DNS) service.
    #define BSD_GETHOSTEN  0


  • When the BSD Sockets are not enabled, the ARM linker does not link the BSD support modules to your application and thus reduces the code size and memory usage.
  • The BSD Socket API uses the underlying native TCP and UDP Sockets.
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