TCT: terminal control table
Use the DFHTCT macro to define SNA logical units (LUs) that support logical device codes and sequential devices attached by BSAM.
A CICS® system can communicate with terminals, sequential devices, logical units, and other systems. The TCT defines each of the devices in the configuration. Each TCT entry defines the optional and variable features of the device to CICS, and specifies the optional and variable features of CICS to be used.
CICS uses a telecommunication access method to communicate with terminals. This can be the z/OS® Communications Server or (for sequential devices) BSAM; you can use one or both of these in your system.
An terminal can be a telecommunication device; for example, an IBM® 3279 Color Display Station, or a subsystem such as an IBM 4700 Finance Communication System. Terminals can be local (channel-attached) or remote (link-attached).
You can use a sequential device to simulate a CICS terminal. You can define a card reader or punch, line printer, direct access storage device (disk drive), or magnetic tape drive as a sequential device.
A logical unit (LU) is a port through which a user of an SNA network gains access to the network facilities.
- Between different processors (intersystem communication or ISC), using the LUTYPE 6.1 or LUTYPE 6.2 protocols, or using an intermediate system as an indirect link. (Intercommunication with non-CICS systems also uses ISC.)
- Within the same processor (multiregion operation or MRO), using interregion communication (IRC). (You can also use LUTYPE 6.2 ISC within the same processor.)