Fault Reactions With Fail-Safe Modules - Siemens SIMATIC S7-1500 System Manual

Not e
S ubstitute v alue behavior of the installed I/O modules during reset to factory s ettings
With "Reset to factory settings", the I/O modules in the station change to the non-configured
state, which means that no input data is acquired and no output data is output.
Reference
You will find more information on the procedure in the STEP 7 online help.
13.6

Fault reactions with fail-safe modules

Safe s tate (safety c oncept)
The basic principle behind the safety concept is the existence of a safe state for all process
variables.
Not e
For fail-safe input and output modules, this safe state is the value "0".
Fault reactions and startup of the F-system
The safety function requires that substitute values (safe state) be output instead of process
values for a fail-safe module (pas sivation of the fail-safe module) in the following cases:
● When the F-system is started up
● If errors are detected during safety-related communication between the F-CPU and the F-
module via the PROFIsafe safety protocol (communication error)
● If F-I/O faults or channel faults are detected (e.g., wire break, discrepancy error)
Detected faults are written to the diagnostic buffer of the F-CPU and communicated to the
safety program in the F-CPU.
F-modules cannot save errors as retentive data. When the system is powered down and
then restarted, any faults still existing are detected again during startup. However, you have
the option of saving faults in your safety program.
Channel faults do not trigger any diagnostic reactions or error handling for channels that
have been set to "deactivated" in STEP 7, even when this channel is affected indirectly by a
channel group fault (Channel parameter "activated/deactivated").
Automation system
System Manual, 09/2016, A5E03461182-AD
WA RNING
13.6 Fault reactions with fail-safe modules
Maintenance
223