How terminals are defined to CICS
Terminal definitions are created as resource definitions or DFHTCT macros, and then added to the terminal control table (TCT) as TCT terminal entries (TCTTEs). DFHTCT macros can only be used for z/OS Communications Server logical units supporting logical device codes and sequential devices attached by BSAM. All z/OS Communications Server connected terminals, intersystem communication links, and multiregion operation links are defined using resource definition online (RDO).
When a cold start is performed, CICS obtains its TCT entries from DFHTCT macros or from groups of resource definitions in the CSD file, which are named in the GRPLIST system initialization parameter. These are recorded in the CICS catalog.
When a warm start is performed, CICS obtains the definitions from the DFHTCT macros and from the CICS catalog; the GRPLIST is ignored.
On emergency restart, CICS obtains the definitions from the DFHTCT macros and from the CICS catalog; the GRPLIST is ignored. Then CICS re-applies any in-flight TCT updates using information from the system log.
- By using the CEDA INSTALL command
- By the autoinstall process when an unknown terminal logs on
- By the transaction routing component when a TCT entry is shipped from a terminal-owning to an application-owning region.
- By using the EXEC CICS CREATE command
- By using the EXEC CICS DISCARD command
- By the autoinstall process when an autoinstalled terminal logs off or has been logged for a period.
- By the transaction routing component when a TCT entry has been unused for a period.
- Using the CEDA INSTALL, EXEC CICS CREATE, transaction routing, or autoinstall processes to replace the old entry.
