HP OpenVMS Systems Documentation

Content starts here

HP OpenVMS DCL Dictionary

Previous Contents Index


Connects your terminal to a specified service available on the local area network (LAN), establishing one session for communication between your terminal and that service.

The service node that provides the service must be on the same extended LAN and must be running at least Version 5.0 of the LAT protocol.


SET HOST/LAT service-name



Specifies the name of the service to which you want your terminal connected. A service is a resource on the LAN. A service often consists of all of the resources of a computer system. Other examples of services are a file storage system and an application program running on a computer system. A computer system that offers one or more services is called a service node.

If several service nodes offer the same service, and you do not specify the /NODE=node-name qualifier, your terminal connects to the service node that is the least busy.

To display a list of services on your LAN, use the LAT Control Program (LATCP) SHOW SERVICES command. Refer to the HP OpenVMS System Management Utilities Reference Manual.


The SET HOST/LAT command allows you to connect your terminal to a specified service, establishing one LAT session for communication between your terminal and that service. (For an overview of the LAT protocol and its advantages, see the HP OpenVMS System Manager's Manual.)

The service node that provides the service must be on the same extended LAN and must be running at least Version 5.0 of the LAT protocol.

Some services are password protected. You are prompted for a password unless you specify the password with the /PASSWORD qualifier.

Once the connection to the service is made, you can interact with the service as if your terminal is directly connected to it. Some services will prompt you. For example, if the service is an OpenVMS system, it prompts you for a user name and password. You must have an account on the service node to log in.

Press the disconnect character to end the LAT session and return to DCL command level on your local system. With some services, such as general timesharing services like OpenVMS, you can end the LAT session by logging out of the service. The default disconnect character is Ctrl/\. Use the /DISCONNECT qualifier to change the default disconnect character.




Specifies whether connection attempts should be retried automatically when a connection fails because a service is unknown or unavailable, or because a node is unknown or unreachable. Also specifies that reconnects should be attempted automatically if a service has disconnected abnormally. The default is /NOAUTOCONNECT.

/AUTOPROMPT (default)


Causes an OpenVMS Username: prompt to appear with no user action when a SET HOST/LAT command is issued.

On a terminal server port, you can configure the port to have AUTOPROMPT disabled (/NOAUTOPROMPT) so that you are required to press Return when connecting to a node to get the Username: prompt; however, when connecting to a reverse LAT service, the AUTOPROMPT characteristic should be disabled.


Defines a character that generates a break on lines that expect a break rather than a carriage return. To generate a break, press the Ctrl and break-character keys together. The default break-character value is the tilde (~).

You can select any ASCII character between @ and Z, except C, M, Q, S, Y, and the left bracket ([). You cannot select a character that is already defined as the disconnect character.


Specifies the port on a node to which you want to connect. The /NODE qualifier is required when you specify the /DESTINATION_PORT qualifier. The port must be available and must offer the service you specify. OpenVMS and certain other LAT service node systems ignore the /DESTINATION_PORT qualifier.


Allows a modem attached to the outgoing terminal line to be autodialed using the autodial protocol of that modem. The NUMBER keyword is the telephone number to be autodialed and is a required parameter.

The MODEM_TYPE keyword is optional. It can be used to specify any of the following modem types:

  • DMCL (any modem that uses the DEC Modem Command Language)
  • DF03 (default)
  • DF112

Each modem type requires a specific modem dialer code. Check with your system manager to see which modem dialer codes are installed on your system.

In addition, the MODEM_TYPE keyword can be used to specify a modem type other than DF03, DF112, or DMCL. A template is provided for users interested in supporting other modems with autodial capabilities (see SYS$EXAMPLES:DTE_DF03.MAR).


Defines the character that you can use to disconnect from a remote session. To generate a disconnect, press the Ctrl and disconnect-character keys together. The default disconnect-character is the backslash (\).

You can select any ASCII character from @ through Z, except C, M, Q, S, Y, and the left bracket ([). For example, if you specify /DISCONNECT=A, Ctrl/A will be the disconnect character. You cannot select a character that is already defined as the break character.

/EIGHT_BIT (default)


Determines whether the outgoing terminal line supports 8-bit or 7-bit characters. By default, 8-bit characters are supported. If you specify /NOEIGHT_BIT, then 7-bit characters are supported.


To change the number of bits per character on the remote terminal server port, that port must have the REMOTE MODIFICATION characteristic enabled.


The /FRAME=n qualifier allows a user making a LAT connection to a remote system to specify the number of data bits that the terminal driver expects for every character that is input or output. The value of n can be from 5 to 8. The default value depends on the settings for the terminal established by the /PARITY and /EIGHT_BIT qualifiers. The following example specifies a character frame size of 7 bits per character:



Logs all data that is delivered during the LAT session. If you do not specify a log file, the data is stored in the file SETHOST_LAT.LOG.


Specifies the node that offers the service to which you want to connect. Failover is not performed if the connection fails.


Specifies the password required by a service that is password protected. If you do not specify the /PASSWORD qualifier when requesting a connection to a password-protected service, you are prompted for a password.


/NOQUEUE (default)

When connecting to a reverse LAT service that is already in use (such as a dial out modem), you are notified that the service is in use and the SET HOST/LAT command terminates. However, LAT can allow incoming connections to be queued to any reverse LAT service that supports service queueing, which enables users to be placed on a queue when using reverse LAT services.

LAT reports your position in the queue. When the resource becomes available, you are immediately notified. You can cancel the queued connection by pressing Ctrl/Y and terminating the SET HOST /LAT command.


Sets the baud rate at which the terminal receives and transmits data. If the input and output rates are the same, specify the qualifier as /SPEED=rate.

Not all terminals support different input and output baud rates. For specific information on baud rates for your terminal, consult the manual for that terminal.

The default transmission rates are installation dependent.

The valid values for input and output baud rates are as follows:

300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600

If you select an invalid or unsupported speed, the terminal line speed will remain set at its previous value.


To change the speed on the terminal server port, the REMOTE MODIFICATION characteristic must be enabled on that terminal server port.

When initiating a connection, SET HOST/LAT may attempt to set terminal server port characteristics, such as the speed and the default speed for a LAT device. If the device connected to the terminal server port has a fixed speed (such as a dial-out modem) and you do not want the host to try to change this, disable the REMOTE MODIFICATION characteristic on that port using the following command:


Use the following command for terminal servers that support the CHANGE command:




%LAT-S-CONNECTED, session to SORTER established
%LAT-I-TODISCON, type ^\ to disconnect the session
Username: BARKER

BARKER logged out at 30-DEC-2001  11:04:51.45
%LAT-I-DISCONNECTED, session disconnected from SORTER
-LAT-I-END, control returned to node HOME

This SET HOST/LAT command connects the user to the service SORTER, which is a computer system. The first message confirms that the user has been connected to that service. The second message informs the user how to disconnect the session. (The user can also disconnect the session by logging out from SORTER.) SORTER then prompts for the username and password. Use the normal login procedure to log in to the system. When the user logs out of the service SORTER, the terminal displays the DCL command prompt of the user's local processor system (HOME).



This command connects the user's terminal to the service BUDGET that is offered on port BOSTON, on service node STATE. The user can disconnect the session by pressing Ctrl/F.



This command attempts to connect the user's terminal to the service PURSE. The service PURSE is password protected, so the user is prompted for a password. The user could have specified the password within the SET HOST/LAT command, as shown in the next example.



This command connects the user's terminal to the password-protected service PURSE. The password is BEOR.

Previous Next Contents Index