Siemens SIMATIC S7 Functional Safety Manual page 32

Getting started
2.2 Configuring
3. Locate the "Fail-safe: F-parameters" area.
You can change the following parameters or accept the default setting:
– "Basis for PROFIsafe addresses": Any value is suitable for a stand-alone fail-safe S7-
– "Default F-monitoring time for central F-I/O": A valid current safety message frame
Leave the default values unchanged for this example.
4. Move to the "Protection" area.
Select the "Protection" property to select the protection level and enter passwords. "Full
access incl. fail-safe (no protection)" protection level with a fail-safe write protection
password is the lowest level for a fail-safe CPU. Enter and confirm a password for the
required protection. Passwords are case-sensitive.
When you download this configuration to the fail-safe CPU, the user has HMI access and
can access HMI functions without a password. To read data, the user must enter the
configured password for "Read access", the password for "Full access (no protection)", or
the password for "Full access incl. fail-safe (no protection)". To write data, the user must
enter the configured password for "Full access (no protection)" or the password for "Full
access incl. fail-safe (no protection)".
32
1200 CPU with local fail-safe SMs.
must be received from the fail-safe CPU to a fail-safe SM within the F-monitoring time.
Otherwise, the fail-safe SM goes to safe state. The F-monitoring time must be set high
enough so that message frame delays are tolerated and, at the same time, low
enough that the process can react as quickly as possible when a fault occurs. By
default, the F-monitoring time for each fail-safe SM is taken from the "Default F-
monitoring time for central F-I/O" parameter of the fail-safe CPU. However, you can
configure the F-monitoring time individually for each fail-safe SM. Refer to Section 5.2:
"Configuring common F-parameters" (Page 106) for further information.
S7-1200 Functional Safety Manual
Manual, 02/2015, A5E03470344-AA