Safety
Fail-Safe Systems
7-18 A5E00085588-03
• The specified I/Os must be checked in the case of the following fail-safe
blocks:
Fail-Safe Block I/O Description
F_CYC_CO MAX_CYC Maximum permissible
F cycle time
F_SENDBO, F_RCVBO
F_SENDR, F_RCVR
TIMEOUT Monitoring time during
communication between F-
CPUs
F_R_R, F_R_BO TIMEOUT Monitoring time during
communication between F-
run-time groups
F_M_DI8
F_M_DI24
F_M_DO10
F_M_DO8
F_M_AI6
TIMEOUT Monitoring time for
PROFIsafe communication
with F-I/O
F_M_DI8
F_M_DI24
F_M_DO10
F_M_DO8
F_M_AI6
LADDR
LADDR_R
Logical address of the
module (SM1)
Logical address of the
redundant module (SM2)
F_M_AI6 MODE_00 to MODE_05 Measurement range coding
in the case of an analog
input module
F_CH_DI,
F_CH_DO, F_CH_AI
ACK_NEC Acknowledgment required
for reintegration
F_LIM_HL QH 1: Upper limit violated
F_LIM_LL QL 1: Lower limit violated
F_RS_FF Q Output
F_SR_FF Q Output
F_CTUD CV Current count value
Switched output parameters are marked with an asterisk (*) on the printout.
Checking the Signatures
Overall signature: After the program has been downloaded to the CPU (see the
sections entitled "Downloading the Whole Safety Program" and "Downloading
Changes"), you have to compare the overall signature of the program in the CPU
with the overall signature in the accepted printout. In the case of S7 FH systems,
you have to make this comparison for both CPUs.
Signatures and initial-value signatures of the F-Blocks: The signatures and
initial-value signatures of all the fail-safe blocks must be identical with those in
Annex 1 of the certificate report. When you use newly created F-Block types, you
must carry out this comparison for all the F-Blocks called in the F-Block type.