Event Detection Of The Cpus 41X As Dp Master; Evaluation In The User Program - Siemens SIMATIC S7-400H Manual

Event Detection
Table 4-8 shows how the CPU 41x acting as a DP master detects any changes in
the operating mode of a CPU as DP slave or interruptions in data transfer.
Table 4-8
Event
Bus
interruption
(short circuit,
plug removed)
DP slave:
RUN → STOP
DP slave:
STOP → RUN

Evaluation in the User Program

The following table shows you how, for example, you can evaluate RUN-STOP
transitions of the DP slave in the DP master (see also Table 4-8).
In the DP Master
Diagnostics addresses: (example)
Master diagnostics address=1023
Slave diagnostics address in the master
system=1022
The CPU calls OB 82 with the following
information, amongst other things:
•
OB 82_MDL_ADDR:=1022
•
OB82_EV_CLASS:=B#16#39
(incoming event)
•
OB82_MDL_DEFECT:=module
malfunction
Tip: This information is also in the diagnostics
buffer of the CPU
You should also program the SFC 13
"DPNRM_DG" in the user program to read
out the DP slave diagnostics data.
We recommend you use SFB 54 in the DPV1
environment. It outputs the interrupt
information in its entirety.
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07

Event detection of the CPUs 41x as DP master

•
OB 86 called with the message Station failure
(incoming event;
diagnostics address of the DP slave that is assigned to the DP
master)
•
In the case of I/O access: Call of OB 122 (I/O access error)
•
OB 82 is called with the message Faulty module
(incoming event; diagnostics address of the DP slave that is
assigned to the DP master; tag 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 master; Variable OB82_MDL_STOP=0)
Installation of a CPU 41x-H
What Happens in the DP Master
In the DP Slave (CPU 41x)
Diagnostics addresses: (example)
Slave diagnostics address=422
Master diagnostics address=not relevant
CPU: RUN → STOP
CPU generates a DP slave diagnostics
frame.
4-39