Technical data

5.6.9
Communication Errors
(FE-3)
If problems occur on the second serial interface with the computer
link RK 517, data transfer with procedure 3964/3964R, data transfer
with "open driver" or data transfer with SINEC L1, the system
program calls organization block
OB 35 and transfers additional
information about the problems to ACCU 1.
Response in the case of
unloaded OB 35
If you do not program OB 35, the system program does not react and
the CPU does
not go into the stop mode. This is the default reaction.
If you want the CPU to go into the stop mode when an interface error
occurs and you do not program OB 35, you must change the default in
DX 0.
Error information in ACCU 1 Every 100 ms the system program checks whether communication
errors have occurred on the second serial interface. If an error is
detected, the system program transfers the error information to ACCU
1 and ACCU 2. If you program OB 35, the system program calls it
and transfers the error information in ACCU 1 and ACCU 2.
Error numbers for a maximum of three causes of problems can be
transferred when OB 35 is called. If there are more than three causes
of problems at the same time, this is indicated by a special overflow
identifier.
Structure of the error
information in ACCU 1 and
ACCU 2
31 24
23 18 15 8 7 0
ACCU 1 0 0 0 0 F U B 0 Error number
1
Error number
2
Error number
3
F = ’0’, when there is no error entered in the error area
= ’1’, when there is an error entered in the error area.
U = ’0’, when there is no error overflow (maximum three entries)
= ‘1‘, when there is an error overflow (more than three entries)
B = ’0’, when there is no BREAK on the interface
= ’1’, when there is a BREAK on the interface
5
Errors in RUN and in RESTART
CPU 928B Programming Guide
C79000-B8576-C898-01 5 - 61