Commands issued at an MVS™ console (or in a job stream) can be directed to a CICS® region
running as a started task, or job, using the MVS MODIFY command. Before CICS
can accept the MVS command, it needs an entry in the terminal control table
for the console issuing the command, which CICS terminal control can use to
display a response. The following discussion describes how CICS handles commands
(transaction invocations) it receives from an MVS operator console:
- Pre-installed console definitions
- When MVS receives your request, it identifies the CICS region from the
task or job name, and passes your request to CICS.
CICS
extracts the console's name from the MODIFY data, and searches the terminal
control table (TCT) for a CONSNAME entry that matches the console name. If
CICS finds a matching entry, it starts the transaction specified on the MODIFY
command, and the transaction can send the results to the console using the
termid of the console's entry in the terminal control table.
- Autoinstalled console definitions
- If CICS fails to find a matching entry, it checks the autoinstall status
for consoles to determine whether it can perform an autoinstall for the console.
If
autoinstall for consoles is active, CICS searches the autoinstall model table
(AMT) and initiates the autoinstall process for the console. CICS either:
- Passes a list of autoinstall model definitions to the autoinstall control
program, together with information about the console, or
- Automatically uses the first console model definition it finds, or a console
model with the same name as the console, and autoinstalls the console using
a CICS-generated termid, without calling your autoinstall control program.
Which of these options CICS takes is determined by the autoinstall
status for consoles. The autoinstall status for consoles is either set at
startup by the AICONS system initialization parameter, or dynamically by a
CEMT (or EXEC CICS) SET AUTOINSTALL CONSOLES command.
- The terminal autoinstall control program
- You use the same autoinstall control program for console autoinstall as
for VTAM® terminals
and APPC connections, specifying the name of the control program on the AIEXIT
system initialization parameter.
If the autoinstall control program is
invoked (either the CICS-supplied program or your own) it selects one of the
models and provides the rest of the information necessary to complete a TCT
terminal entry for the console. When the autoinstall control program returns
control, CICS builds a terminal control table terminal entry (TCTTE) for the
console using the autoinstall model, the termid, and other data returned by
the autoinstall control program, and MVS console data. CICS then adds the
new entry to the TCT and starts the transaction specified on the MODIFY command.
- Preset security for autoinstalled consoles
- If the model terminal specifies USERID(*FIRST) or USERID(*EVERY), CICS
uses the user ID passed by MVS on the MODIFY command to sign on the console,
in effect using the MVS-passed user ID as the preset userid for the new console.
- Automatic deletion of autoinstalled consoles
- CICS automatically deletes autoinstalled consoles if they are unused for
a specified delay period (the default is 60 minutes). As part of the install
function, the autoinstall control program can set a 'delete-delay' value for
the console. The delete-delay period is the length of time (in minutes) that
an autoinstalled console can remain installed without being used before CICS
deletes it. Setting this value to 0 inhibits automatic deletion. Autoinstalled
consoles are not recorded on the catalog and not recovered at restart. Note
that a console is deleted even if there is a currently signed-on user.