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Starting and stopping the logon address space (LAS)

The LAS must be running to support user logons from VTAM terminals. It is not used for VTAM or EXCP AutoLogon sessions.

(For more information about how the LAS functions, see Logon Address Space (LAS) functions.)

See the following information:

Starting the LAS

The LAS runs as a started task.

The LAS proc must execute from a procedure library, such as SYS1.PROCLIB.

To start the LAS

Issue the following START command to start the LAS by using the default parameter list that is defined in the LAS PROC:


Keep the following information in mind when using the START command:

  • The command assumes that the default LAS PROC name, BBVLAS, was not changed during customization.

  • If a LAS named BBVLAS already is operational, this command fails. The first LAS must be stopped before a new LAS can be started; see Stopping the LAS for more information. If you want to run more than one LAS, see To start multiple LASs.

  • To define the LAS so that it initializes at IPL, add this START command to an IPL procedure such as the COMMNDxx member of SYS1.PARMLIB.

  • If you do not want to use the default parameters and you want to define a different parameter list for LAS initialization, see Controlling LAS initialization parameters.

To start multiple LASs

You might want to start one LAS for user access to the MainView Selection Menu and additional LASs for access directly to various MainView product menus. You can run more than one LAS on the same system at a time; however, two LASs cannot run concurrently while using the same minor node root name. Therefore, you must perform the following customization to support multiple LASs:

  1. Define a different VTAM application major node and minor nodes, specifying a different minor node root name (see Step 2: (optional) Defining the VTAM major and minor nodes).
  2. Define a LAS PROC with a unique name (see Step 8: (optional) Defining a LAS startup procedure).
  3. Define a LAS initialization parameter list member named BBVLASxx (see Step 7: (optional) Defining a default LAS initialization parameter list).
  4. In this BBVLASxx member, specify the
    • VTAM minor node root name that was created at the APPLID parameter in Step 1

    • Unique name of the proc that was created at the PROCNAME parameter in Step 2

    See Understanding LAS initialization parameters for more information about these parameters.

Controlling LAS initialization parameters

LAS initialization parameters are used to set the LAS environment when the LAS initializes.

(Initialization parameters are described in Understanding LAS initialization parameters.) These initialization parameters are defined in a parameter list member in hilevel.sysid.UBBPARM. The default parameter list member is BBVLAS00. BBVLAS00 is created during customization, but you can define other parameter list members (see Defining other LAS and TAS initialization parameter lists).

The SUF=xx keyword on the BBVLAS PROC statement specifies which parameter list member is used to initialize the LAS (the xx value is a two-character suffix belonging to a BBVLASxx member in UBBPARM). BBVLAS00 is the default member for the LAS because SUF=00 is the default keyword value. When the LAS initializes, it reads the parameter list member that the SUF keyword points to.

You can override the SUF parameter value that is defined on the BBVLAS PROC statement at LAS initialization by specifying the SUF parameter and the suffix of a different parameter list member in the LAS START command.

To initialize the LAS with a different parameter list member

  1. Specify the following START command:


    In the command, xx is the two-character suffix belonging to a BBVLASxx member in UBBPARM.


    This command assumes that the default LAS proc name, BBVLAS, was not changed during customization. For example, you can specify the following command:


    As a result, the LAS is started using the parameter list that is defined to member BBVLAS01 in UBBPARM

Stopping the LAS

When the LAS is operational, there should be no need to stop it unless you want to change the initialization parameters. When you do stop the LAS, you do not affect any currently active VTAM terminal sessions, but new VTAM terminal users who want to log on through MainView Alternate Access cannot do so.

For more information, see Controlling LAS initialization parameters.

To stop the LAS

  1. Issue the following operator STOP command:


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