5.6.1. Terminal

The Terminal component is a virtual component that permits UART data to be transferred between a TCP/IP socket on the host and a serial port on the target. The component itself is described in TelnetTerminal component.


If you want to use the Terminal component with a Microsoft Windows 7 client you must first install Telnet. The Telnet application is not installed on Microsoft Windows 7 by default. You can download the application by following the instructions on the Microsoft web site. Run a search for “Windows 7 Telnet” to find the Telnet FAQ page, or see http://windows.microsoft.com/en-US/windows7/Telnet-frequently-asked-questions. To install Telnet:

  1. Select Start → Control Panel → Programs and Features. This opens a window that lets you uninstall or change programs.

  2. Select Turn Windows features on or off in the left-hand side bar. This opens the Windows Features dialog. Select the Telnet Client check box.

  3. Click OK. The installation of Telnet might take several minutes to complete.

A block diagram of one possible relationship between the target and host through the Terminal component is shown in Figure 5.74. The TelnetTerminal block is what you configure when you define Terminal component parameters. The Virtual Machine is your model system.

Figure 5.74. Terminal block diagram

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On the target side, the console process invoked by your target OS relies on a suitable driver being present. Such drivers are normally part of the OS kernel. The driver passes serial data through a UART. The data is forwarded to the TelnetTerminal component, which exposes a TCP/IP port to the world outside of the model. This port can be connected to by, for example, a Telnet process on the host.

You can change the startup behavior for each of up to four Terminals by modifying the corresponding component parameters. See Parameters.

If the Terminal connection is broken, for example by closing a client telnet session, the port is re-opened on the host. This could have a different port number if the original one is no longer available. Before the first data access, you can connect a client of your choice to the network socket. If there is no existing connection when the first data access is made, and the start_telnet parameter is true, a host telnet session is started automatically.

The port number of a particular Terminal instance can be defined when your model system starts. The actual value of the port used by each Terminal is declared when it starts or restarts, and might not be the value you specified if the port is already in use. If you are using Model Shell, the port numbers are displayed in the host window in which you started the model.

You can start the Terminal component in one of two modes:

Telnet mode

In telnet mode, the Terminal component supports a subset of the RFC 854 protocol. This means that the Terminal participates in negotiations between the host and client concerning what is and is not supported, but flow control is not implemented.

Raw mode

Raw mode permits the byte stream to pass unmodified between the host and the target. This means that the Terminal component does not participate in initial capability negotiations between the host and client, and instead acts as a TCP/IP port. You can take advantage of this feature to directly connect to your target through the Terminal component.

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