Siemens SIMATIC S5 Manual page 196

S5-115F Manual
Any errors found are evaluated by the central error routine and entered in error DBs 2 and 3.
Subunit A writes its error into error DB 2 and subunit B writes its error into error DB 3. If the error
does not cause the link between the two subunits to be interrupted, the subunits are synchronized
by exchanging the error DBs. Figure 5-7 describes the structure of the error DBs.
Meaning of the errors in the error DB:
Error response; meaning of the set bit:
7 6 5 4
Self-test identifier
F error (bit is set in the case of errors with PLC STOP response)
F error (bit is set in the case of errors with PLC STOP response)
Subunit identifier
ASCII characters A or B
Signal group number:
A bit is assigned to each signal group.
If there has been a fault on a SINEC L1 data path, the number of the source slave is stored
here.
Error buffer
The error buffer contains error messages in eight-byte records, just as they are output by the
operating system. The first error message with stop response reaches record 2 of the error
stack.
Errors with stop response can attract other messages as well as the main message (records
2 to 5). After passivation of a signal group, the S5-115F remains in RUN mode. These messages
are stored in the passivation message stack. Record six contains the message of the last
passivation error to occur.
Marking field for passivated I/O modules
The user can see from this which I/Os have been passivated:
Bit=1: The relevant I/O word or the relevant I/O channel
- has caused passivation and
- is passivated.
COM 115F constructs the error messages using the information stored here ( Appendix B).
EWA 4NEB 811 6149-02
3 2 1 0
Lesser stop loop
Error detected on one side
Large stop loop
Passivation request
Passivation implemented
Error Diagnostics
5-15