Technical data

5.4 Error Handling using Organization Blocks
When the system program detects an error, it calls the appropriate
organization block to handle it. You can determine how the CPU
reacts by programming the relevant organization block.
Depending on how you program the organization block, you can
achieve the following reactions:
•• normal program processing is continued
•• the CPU goes to the STOP mode
and/or
•• a special error handling program is run through.
Organization blocks exist for the following causes of errors:
Cause of error Organization
block called
Reaction of CPU
if OB is not
programmed
1)
Call of a block that is not loaded (LZF) OB 19 STOP
Timeout in the user program during access to I/O
modules (QVZ)
OB 23 none
Timeout during update of the process image and during transfer of
IPC flags (QVZ)
OB 24 none
Addressing error (ADF) OB 25 STOP
Cycle time exceeded (ZYK) OB 26 STOP
Substitution error (SUF) OB 27 STOP
Mode selector set to STOP, PG function PC STOP,
STOP from S5 bus (multiprocessor operation)
OB 28 STOP
Operation code error (BCF) OB 29 STOP
Parameter error (BCF) OB 30 STOP
Other runtime errors (LZF) OB 31 STOP
Load/transfer error with data blocks (TRAF) OB 32 STOP
Collision of time interrupts (WECK-FE)
OB 33 STOP
Table 5-8 The organization blocks called in case of errors
5
Error Handling using Organization Blocks
CPU 928B Programming Guide
C79000-B8576-C898-01 5 - 29