Telnet Server

This example shows how the Telnet server can be used to implement a Command Line Interface (CLI) to interact with the device.

The following picture shows an exemplary connection of the development board and a Computer.

Telnet example hardware setup

Project Organization

The Telnet Server project is available as part of the Network Reference examples.

Application Source Files

Following files implement application-specific logic in the example:

• Telnet_Server.c contains the application main thread which initializes the Network Component.
• Telnet_Server_UIF.c defines the functions for the user interface and all the available CLI commands.

You can add the following optional files, which are not included in the project by default:

• Telnet_Server_Multiuser.c is used for specifying multiple users and access rights for these users.
• Telnet_Server_Access.c enables the server to accept or block connection requests from certain remote clients.

Software Components Configuration Files

Configuration files for the software components used in the project are located in the ./RTE/ directory and can be modified by users to adjust the operation of related components.

Following configuration files are provided with this example:

• For the Network component, in ./RTE/Network/ folder:
  • Net_Config_Telnet_Server.h: Telnet Server configuration
  • Net_Config_TCP.h: TCP Socket configuration
  • Net_Config_UDP.h: UDP Socket configuration
  • Net_Config_ETH_0.h: Ethernet Interface configuration
  • Net_Config.h: Network Core configuration
  • Net_Debug.h: Network Debug configuration
• For the CMSIS components, in the ./RTE/CMSIS/ folder:
  • RTX_Config.h and RTX_Config.c: CMSIS-RTX Configuration files for the RTOS Kernel

When a board layer is added to the project, corresponding configuration files for the board and device components will become available in the local ./Board/ directory.

Board Layer

In order to build the project it shall be extended with a compatible board layer that provides following interfaces as connections:

• CMSIS_ETH: CMSIS-Driver for Ethernet interface
• CMSIS_VIO: CMSIS-Driver for Virtual I/O interface
• STDIN: Standard Input redirection
• STDOUT: Standard Output redirection

Build the Project

Working with MDK-Middleware Examples explains the workflow for accessing, configuring and building an MDK-Middleware example project for your target hardware.

1. Open the Network MDK-Middleware reference example.
2. Make sure the compatible board layer is configured.
3. Select Telnet_Server as an active project for the build process.
4. Build the project and observe that no errors are reported.

Run the Example

Setup

Board-specific hardware setup such as jumpers, Ethernet ports, power supply, etc. is documented in the board layer description (README.md) of your selected target.

1. Load the executable image to the target development board.
2. Use an Ethernet cable to connect your development board to the local area network. The PC is assumed to be already in this LAN.

Example execution

For opening a Telnet session to your development , you need a Telnet client on the host PC, for example PuTTY.

In the Telnet client use my_host (or the respective hostname that you have chosen in the Net_Config.h file) as the host name and use the standard Telnet port 23.

You will be asked for a username and password combination. Use admin for the user name and no password (you can change the defaults in the Net_Config_Telnet_Server.h file). After a successful log in, enter help command and you should see the list of available commands like this:

Telnet Command Line Interface