Application example: Safety Functions
A.2 Components and settings used
Fail-safe operation of the Mobile Panel 277F IWLAN
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Function Manual, 08/2008, 6AV6691-1FQ01-2AB0
Setting
Explanation
Inputs:
Here, define the starting addresses
of the inputs and the process image
to which this address area belongs
(PII).
Outputs:
Here, define the starting addresses
of the outputs and the process
image to which this address area
belongs (PIQ).
F_Dest_Add:
PROFIsafe address of the Mobile
Panel 277F IWLAN. This address
must match the address on the HMI
device.
F_WD_Time (ms):
Monitoring time in the fail-safe IO
device.
A valid current safety message
frame must reach the F-CPU and be
returned to the HMI device within the
monitoring time period. This ensures
that failures and errors are detected
and appropriate responses, which
keep the fail-safe system in a safe
state or transfer it to a safe state,
are triggered.
The monitoring time selected must
be long enough that message frame
delays will be tolerated by the
communication system, but also that
the fault reaction function responds
quickly enough in the event of a fault
(e.g. interruption in the
communication connection).
