Technical data

Cause of error Organization
block called
Reaction of CPU
if OB is not
programmed
1)
Table 5-8 continued:
Error processing the controller structure R64 (REG-FE) OB 34 STOP
Communication error on the 2nd serial interface (FE-3) OB 35 none
1)
with DX 0 defaults
Response of organization
block not loaded
If the organization block is not loaded the response depends on the
particular error:
No interruption of cyclic
program execution
If a timeout occurs and OB 23, OB 24 or OB 35 is not loaded, cyclic
program execution is
not interrupted. The CPU does not react.
If you want the CPU to go into the STOP mode when a timeout
occurs, the organization block must contain a stop statement and be
completed with the block end statement BE or DX 0 must have
suitable parameters assigned.
Program for STOP:
:
:
:STP
:BE
STOP mode When any other error occurs, the CPU goes into the STOP mode
immediately if you did not program the appropriate organization
blocks.
If, in exceptional circumstances, (e.g. during system installation) you
do not want one of these errors to interrupt cyclic program execution,
a block end statement in the appropriate organization block is
sufficient or assign suitable parameters to DX 0.
Program for uninterrupted operation:
:
:
:BE
Note
Organization block OB 28 is an exception: here, the CPU always
goes to the STOP mode regardless of whether you have loaded
OB 28 or not.
Error Handling using Organization Blocks
CPU 928B Programming Guide
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