Returning information to CICS

At the INSTALL event, the autoinstall control program is responsible for allowing or denying the installation of a new console resource in the CICS® region. This decision can be based on a number of installation-dependent factors, such as security, or the total number of connected terminals. CICS takes no part in any such checking. You decide whether any such checking takes place, and how it is done.

Procedure

  • If you want an INSTALL request to proceed, perform these steps in your autoinstall control program:
    1. Return an autoinstall model name in the first 8 bytes of the area addressed by fullword 4 of the parameter list.

      All the models in the list passed to your program are for consoles. That is to say, a viable TCT entry usually results from the use of any one of them. The default autoinstall control program picks the first model in the list. However, this model may not provide the attributes required in all cases. Your control program must be able to select the model that provides the characteristics you require for the console, for example, one that has the required security characteristics.

    2. Supply a CICS terminal name (TERMID) in the next four bytes of the return area. DFHZATDX and DFHZATDY take the last four non-blank characters of the console name (addressed by fullword 2 of the parameter list) as the terminal name. If this does not meet with your installation's naming conventions, code your own autoinstall program.
    3. Set the return code to X'00'. On entry to the autoinstall control program, the return code always has a nonzero value. If you do not change this, the autoinstall request is rejected.
    4. Set the delete delay period, or leave it set to the default value of 60 minutes.
    Note that these are the only attributes of the TERMINAL definition that can be set by the autoinstall control program; all other attributes must come from one of the following sources:
    • The z/OS® console interface block (CIB)
    • The autoinstall model TERMINAL definition
    • The TYPETERM definition to which it refers
  • If your control program decides to reject the INSTALL request, it should return to CICS with a non-zero value in the return code. Having completed processing, the control program must return to CICS by issuing an EXEC CICS RETURN command.

Setting the TERMINAL value

The TERMINAL value must be unique, and must be 1 - 4 characters long. The TERMINAL value is the name or identifier that CICS uses for the console. The CONSNAME value is the identifier z/OS uses for the console.

If the control program attempts to install a TCT entry for a TERMINAL value that already has a TCT entry, the installation is rejected, even if the terminal is eligible and a suitable model has been found. However, if a MODIFY command is received from a z/OS console for which CICS already has an entry in the TCT with a matching CONSNAME value, CICS uses that entry and does not start your autoinstall control program.

The default autoinstall control program creates the TERMINAL value from the last four non-blank characters of the CONSNAME value, which means that the terminal name might not be unique. One way of overcoming this problem is to use the CICS Explorer® Terminals operations view or the EXEC CICS INQUIRE command from the control program, to determine whether the TERMINAL value is already in use. If it is, modify the last character and check again.