Terminal error processing
There are two main CICS® programs that participate in terminal error processing. These are the node error program, DFHZNEP, and the terminal error program, DFHTEP.
CICS controls terminals
by using z/OS® Communications
Server (in conjunction with NCP for remote terminals). These communication
access methods detect transmission errors between the central processing
complex (CPC) and a remote terminal, and automatically invoke error
recovery procedures, if specified. These error recovery procedures
generally involve:
- Retransmission of data a defined number of times or until data is transmitted error-free.
- Recording of information about the error on a data set, or internally in control blocks. You can, at times, access data recorded in control blocks using communication system commands.
If the data is not transmitted successfully after the specified number of retries:
- CICS terminal management is notified.
- One of the following CICS terminal error transactions is initiated:
- Control can pass to a user-written node error program (DFHZNEP).
- Control can pass to a user-written terminal error program (DFHTEP).