RL-ARM User's Guide

Telnet Server

RL-TCPnet has integrated a tiny Telnet Server, which is a command-line oriented application that can be used to remotely connect to your device with the Telnet client.

The following Telnet Server options are configurable from the Net_Config.c configuration file:

• Telnet Server switch enables or disables the Telnet Server service in your application. It is enabled when this value is set to 1. It should be set to 0 when Telnet Server is not used in your application.

  #define TNET_ENABLE    1
  

• Number of Telnet Connections specifies the number of available Telnet sessions. The default value is one, and this enables only one concurrent client connection. You should increase this number if multiple Telnet clients must connect to the Telnet server at the same time.

  #define TNET_NUMSESS   1
  

• Port Number specifies the listening TCP port number. The default Telnet server listening port is 23.

  #define TNET_PORTNUM   23
  

• Idle Connection Timeout in seconds specifies the interval of user inactivity, after which the connection is closed. In idle connection, no TCP frames are exchanged. A value of 0 disables a disconnection on timeout.

  #define TNET_IDLETOUT  120
  

  A value of 0 also enables keep-alive mode of TCP socket. After expiration of TCP_DEFTOUT, a TCP socket sends keep-alive probe to remote peer and expects the acknowledge response. Received acknowledge reloads the timeout counter for the socket. If a response is not received after certain number of retries, a connection is closed.
• Disable Echo switch enables or disables the Telnet Server echo mode. When disabled, the Telnet Server will not echo characters it receives. The echo mode is disabled when this value is set to 1.

  #define TNET_NOECHO    0
  

• Enable User Authentication switch enables or disables the Telnet Server authentication with a username and a password. The user authentication is enabled when this value is set to 1.

  #define TNET_ENAUTH    1
  

• Authentication Username is the username identification.

  #define TNET_AUTHUSER  "admin"
  

• Authentication Password is the default password, that must be stored in Non volatile memory. The user may change the password later.

  #define TNET_AUTHPASSW ""
  

Note

• You must also add the Telnet_uif.c user interface module to your project and customize it. This file is in the \Keil\ARM\RL\TCPnet\User folder.
• When the Telnet server is not enabled, the ARM linker does not link the Telnet support modules to your application and thus reduces the code size and memory usage.