LTERM Assignment

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To activate LTERM assignment, include IMS=ASSIGN in the APPLDEF command that defines an IMS/DC application. The DEST operand of the APPLDEF command specifies the IMS command that defines the IMS/DC subsystem. The following example shows an APPLDEF command for a SINGLE IMS application. 


APPLDEF IMSASSGN                        -
               IMS=ASSIGN                      -
               DEST=IASSIGN                    -
               DESC='IMS ASSIGN (SINGLE)'      -
               POOL='&DEFPOOL'             -
               MULTSESS=NO                     -
               HELP=KLIPGD1                    -
               GROUP=100                       -
               LOGON='\FF\6D\FF\7D\40\40/FOR SCREEN'

For a complete explanation of the APPLDEF command, see CL/SuperSession Customization.

If you specify IMS=ASSIGN in the APPLDEF command, the programmed virtual MTO issues a series of IMS operator commands to inspect

  • the status of the selected PTERM used to establish the new session for the current user
  • the status of the residual LTERMs assigned to that PTERM

The operator command sequence then performs the following steps:

  1. Reassigns the currently active LTERMs to the dummy PTERM established for this purpose in the IMS definition.
  2. Assigns the LTERM associated with the current user to the selected PTERM.

For more information on virtual MTOs, LTERMs, and PTERMs, see Session Service Implementation and IMS Requirements.

The LTERM data element must be included in the gateway configuration member. If a printer LTERM is associated with the session, the PRTNODE and PRTLTERM data elements are also required. If you specify PRTNODE and PRTLTERM, the virtual MTO issues the command sequences twice: once for the terminal and once for the printer node. For more information about CL/SuperSession data elements, see CL/SuperSession Customization.

If more than one user is assigned the same LTERM, or if a user attempts to log onto IMS from two separate sessions, an LTERM can be reassigned during an IMS session. By using extended LTERM verification (XLV), you can prevent this situation. If you specify XLV in the IMS command, a user will not be allowed access to IMS with an LTERM currently in use. The LTERM assignment command sequence issued by the virtual MTO uses a reserved PTERM to manage inactive LTERMs. When a new session begins on a given PTERM, all LTERMs currently assigned to it are reassigned to this reserved PTERM, known as the dummy PTERM (and commonly named FAKENODE).

The dummy PTERM and the LTERM name assigned to each user in the LTERM data element must be identified in the IMS terminal definition. The example below shows system generation statements that define a dummy PTERM and associated LTERMs. For additional IMS gen definition examples, see &thilev.SKLSSAMP(KLGGWIMS). 


TYPE  UNITYPE=SLUTYPE2,MODEL=2,                X
      FEAT=(PFK,NOCD,NOPEN),                   X
      OPTIONS=(TRANRESP,COPY,PAGDEL,OPNDST)
TERMINAL NAME=FAKENODE         DUMMY PTERM
   NAME  USER001               USER LTERM #1
   NAME  USER002               USER LTERM #2