Chapter 8. Writing a terminal error program
Considerations common to all user-replaceable programs
Note that the comments contained in “Chapter 5. General notes about
user-replaceable programs” on page401 apply to this chapter.
This chapter contains information about the CICS terminal error program (TEP),
which handles error conditions for devices that use the TCAM DCB interface or the
sequential access method. Note that node error programs, not terminal error
programs, must be used for VTAM-supported devices.The chapter is divided
into three sections:
1. “Background to error handling for TCAM and sequential devices” is an
overview.
2. “The sample terminal error program” on page 417 describes the
CICS-supplied sample TEP.It contains:
v“Components of the sample terminal error program” on page418
v“Structure of the sample terminal error program” on page419
v“Sample terminal error program messages” on page423
v“Generating the sample terminal error program” on page425.
3. “User-written terminal error programs” on page 437 discusses factors you
need to consider when writing your own terminal error program. It contains:
v“Why write your own terminal error program?” on page438
v“Restrictions on the use of EXEC CICS commands” on page438
v“Addressing the contents of the communication area” on page438
v“Addressing the contents of the TACLE”on page 441
v“Example of a user-written terminal error program” on page445.

Background to error handling for TCAM and sequential devices

CICS terminal error handling is based on the assumption that most users want to
modify CICS operations in response to terminal errors. Because CICS cannot
anticipate all possible courses of action, the error-handling facilities have been
designed to allow maximum freedom for users to create unique solutions for errors
that occur within a terminal network.
The following CICS components are involved in the detection and correction of
errors that occur when TCAM terminals or sequential devices are used:
vTerminalcontrol program (DFHTCP)
vTerminalabnormal condition program (DFHTACP)
vTerminalerror program (DFHTEP).
These components are discussed in the following sections. (The corresponding
CICS components for logical units are discussed in “Chapter 9. Writing a node error
program” on page 449.)
© Copyright IBM Corp. 1977, 1999 415