To reduce setup and maintenance efforts for the VTAM line driver, the "model" link facility has been implemented. This allows users to code one or more model links with parameter values that serve as default values for many partners, instead of coding one LINK statement for each partner. As each partner connects, new control blocks are allocated and initialized from the model link. A model link is defined as any link that meets one of the following criteria: the LUNAME or the APPLID parameter contains one or more wildcard characters (the wildcard character is a question mark), or neither the LUNAME nor the APPLID parameter is specified.
Once a model link is defined, it remains a model link even if its defining characteristics are modified with the ALTER operator command.
The following criteria are used for model link selection:
LU type (LU6.0, LU6.2, LU0)
Parallel session support (Yes/No)
LUNAME or APPLID (wildcard characters match any character)
MODEENT name
The model link selection process may include a call to a user exit to allow the user to make the final selection. The EXIT parameter in the LINK statement is used to specify the name of the user exit. See the section VTAM LINK Statement Parameters . If a user exit is specified, it is called after a model link is selected. The user exit can override the selection by modifying the link name.