Event Detection Of The Cpus 41X As Dp Slave; Evaluation Of Run-Stop Transitions In The Dp Master/Dp Slave - Siemens SIMATIC S7-400 Reference Manual

Event Detection
Table 1-13 shows you how the CPU 41x as DP slave detects any operating mode
changes or interruptions in data transfer.
Table 1-13 Event Detection of the CPUs 41x as DP Slave
Event
Bus interruption
(short circuit,
connector removed)
DP master:
RUN → STOP
DP master:
STOP → RUN
Evaluation in the User Program
The following table 1-14 shows you, for example, how you can evaluate
RUN-STOP transitions of the DP master in the DP slave (see also Table 1-13).
Table 1-14 Evaluation of RUN-STOP Transitions in the DP Master/DP Slave
In the DP Master
Diagnostic addresses: (example)
Master diagnostic address=1023
Slave diagnostic address in the master
system=1022
CPU: RUN → STOP
Automation System S7-400 CPU Specifications
A5E00165965-01
What Happens in the DP Slave
•
OB 86 is called with the message Station failure
(incoming event; diagnostic address of the DP slave that is
assigned to the DP slave)
•
In the case of I/O access: OB 122
called (I/O access error)
•
OB 82 is called with the message Faulty module
(incoming event;
diagnostic address of the DP slave that is assigned to the
DP slave;
Variable OB82_MDL_STOP=1)
•
OB 82 is called with the message Module OK.
(outgoing event;
diagnostic address of the DP slave that is assigned to the
DP slave;
Variable OB82_MDL_STOP=0)
Diagnostic addresses: (example)
Slave diagnostic address=422
Master diagnostic address=not relevant
The CPU calls OB 82 with the following
information, amongst other things:
•
OB 82_MDL_ADDR:=422
•
OB82_EV_CLASS:=B#16#39
(incoming event)
•
OB82_MDL_DEFECT:=module
malfunction
Tip: This information is also in the diagnostic
buffer of the CPU
Structure of a CPU 41x
In the DP Slave
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