Filter
Top Products
Chapter 9. Writing a node error program
Considerations common to all user-replaceable programs
Note that the comments contained in “Chapter 5. General notes about
user-replaceable programs” on page 401 apply to this chapter.
This chapter contains information about the node error program (NEP) of CICS
Transaction Server for OS/390 Release 3. Node error programs, not terminal error
programs, must be used for terminals and logical units supported via the
ACF/VTAM interface.
The chapter is divided into the following sections:
1. “Background to CICS-VTAM error handling” is an overview. If you are not
familiar with the node error program, you should read this section. If you are
familiar with NEPs, you may be able to go straight to the detailed information in
the following sections, and look at the subjects that particularly interest you.
2. “When an abnormal condition occurs” on page 457 describes the CICS
components that are invoked when an abnormal condition is detected from a
VTAM logical unit.
3. “The sample node error program” on page 465 describes the CICS-supplied
sample NEP.
4. “User-written node error programs” on page 475 discusses the factors you
need to consider when writing your own node error program.
5. “Using the node error program with XRF or persistent sessions” on page
480.
Notes:
1. Like the terminal error program for non-VTAM devices, the node error program
for VTAM-attached terminals is available in three forms:
a. The default node error program
b. The CICS-supplied sample node error program
c. User-written versions.
All three types are discussed in the following sections.
2. In this chapter, “VTAM 3270” refers to a non-SNA 3270 connected through
VTAM, and “3270 compatibility mode” refers to an SNA 3270 connected through
VTAM.
3. If you code an EXEC CICS HANDLE CONDITION TERMERR command in your
application program, it is sometimes possible for the application program to
handle exceptional cases, rather than using a node error program. The
‘TERMERR’ condition is driven if the node abnormal condition program
(DFHZNAC) actions an ABTASK (‘ATNI’ abend). Note that ‘TERMERR’ is
application-related, and is not an alternative to the node error program, which
must be used for session-related problems. Dealing with errors in the
application program is particularly useful in an intersystem communication (ISC)
environment. For further information, refer to the
CICS Intercommunication
Guide
.
© Copyright IBM Corp. 1977, 1999 449