The exits

CICS drives the XICTENF exit when the ‘terminal not known’ condition occurs after the interval control program has been invoked by an EXEC CICS START command. CICS drives the XALTENF exit when the ‘terminal not known’ condition occurs after the terminal allocation program has been invoked by the transient data trigger level or the interval control program. Note that an EXEC CICS START command could result in both exits being invoked.

The exit program must indicate whether the terminal exists on another system and, if so, on which one. CICS passes data to the exit program to help establish this information. You can use the same exit program at both exit points. CICS supplies a sample exit program, DFHXTENF, that can be used at both exits and that can deal unchanged with some typical situations.

The exits are designed to deal with ‘terminal not known’ conditions that occur in CICS regions other than the TOR. For a TOR/AOR pair, enable the exit program in the AOR. The exits cannot deal with a ‘terminal not known’ condition in the TOR and the exit program should not normally be enabled there. However, if more than one TOR exists, you may need to enable the exit program in each TOR to deal with requests for terminals owned by other TORs. In this case, the exit program must recognize terminals that should be owned by this system and reject the requests (‘UERCTEUN’). Although the exit provides as much data as possible, the logic of your program depends entirely on your system design. A simple solution to the most complex case would be to make the name of each terminal reflect the netname or sysid of its owning region.