Monitoring and Response Times of F-Systems
A.3 F-Related Monitoring Times for S7 Distributed Safety
Safety Engineering in SIMATIC S7
System Manual, 04/2006, A5E00109529-05
A-7
A.3.4
Minimum Monitoring Time for Safety-Related Master-I-Slave Communication
TIMEOUT Parameter in F_SENDDP and F_RCVDP
Time monitoring takes place in F-application blocks F_SENDDP and F_RCVDP using the
same monitoring time, which must be assigned in both F-application blocks (TIMEOUT
parameter).
To ensure that monitoring does not respond when no errors are present, the selected
TIMEOUT monitoring time must be sufficiently large.
TIMEOUT > T CI,F_ T CI,F 2 x T 2 x TTR
Definition of Times
Time
Definition
Reference
TCI,F_SENDDP
Maximum cycle time of the OB with the
call of F_SENDDP
"Minimum Monitoring Time for F-
Cycle Time"
TCI,F_RCVDP
Maximum cycle time of the OB with the
call of F_RCVDP
"Minimum Monitoring Time for F-
Cycle Time"
TDP_DLY
Additional DP time delay of a PROFIBUS
CP (communications processor)
Object Properties of CP, "Operating
Mode" tab in
HW Config
TTR
Maximum target rotation time for the DP
master system
In
HW Config
: Object Properties for
DP master system, Bus parameters
A.3.5
Minimum Monitoring Time for Safety-Related I-Slave-I-Slave Communication
The information provided in "Minimum Monitoring Time for Safety-Related Master-I-Slave
Communication" applies here.
A.3.6
Minimum Monitoring Time for Safety-Related Communication via S7 Connections
TIMEOUT Parameter in F_SENDS7 and F_RCVS7
Time monitoring takes place in F-application blocks F_SENDS7 and F_RCVS7 using the
same monitoring time, which must be assigned in both F-application blocks (TIMEOUT
parameter).
To ensure that monitoring does not respond when no errors are present, the selected
TIMEOUT monitoring time must be sufficiently large.
Use the Microsoft Excel file provided with S7 Distributed Safety to determine a
recommended TIMEOUT monitoring time for PROFINET IO. The Excel file is available on
the Internet under the contribution ID 19138505 at
http://support.automation.siemens.com/WW/view/en/11669702/133100.