Every OB 82 call causes an entry in the diagnostic buffer of the CPU containing error
cause and module address. By using the SFC 59 you may read the diagnostic bytes. At
de-activated diagnostic interrupt you have access to the last recent diagnostic event. If
you've activated the diagnostic function in your hardware configuration, the contents of
record set 0 are already in the local double word 8 when calling the OB 82. The SFC 59
allows you to also read the record set 1 that contains additional information. After leaving
the OB 82 a clear assignment of the data to the last diagnostic interrupt is not longer pos-
sible. The record sets of the diagnostic range have the following structure:
Byte
Bit 7...0
0
n
Bit 0: set at module failure
n
Bit 1: 0 (fix)
n
Bit 2: set at external error
n
Bit 3: set at channel error
n
Bit 7 ... 4: 0 (fix)
1
n
Bit 3 ... 0: Module class
–
0101b: Analog
–
1111b: Digital
n
Bit 4: Channel information present
n
Bit 7 ... 5: 0 (fix)
2
n
Bit 7 ... 0: 0 (fix)
3
n
Bit 5 ... 0: 0 (fix)
n
Bit 6: Process interrupt lost
n
Bit 7: 0 (fix)
After the removing error a diagnostic message
outgoing
takes place if the diagnostic interrupt
release is still active.
Example:
Diagnostic interrupt pro-
cessing
Record set 0 Diag-
nostic
incoming
Record set 0 Diagnostic
out-
going
VIPA System 300S
+
Deployment I/O periphery
Diagnostic and interrupt > Diagnostic interrupt
HB140 | CPU-SC | 312-5BE23 | en | 18-45
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