Minimum Monitoring Time For Safety-Related Communication Between F-Cpus - Siemens SIMATIC S7 System Manual

A.4.3

Minimum Monitoring Time for Safety-Related Communication between F-CPUs

TIMEOUT Parameter in F_SENDR and F_RCVR or F_SENDBO and F_RCVBO
Time monitoring takes place in F-blocks F_SENDR and F_RCVR or F_SENDBO and
F_RCVBO using
F-blocks (TIMEOUT parameter).
To ensure that monitoring in F_SENDR or F_SENDBO (or F_RCVR or F_RCVBO) does not
respond when no errors are present, the TIMEOUT monitoring time setting must be
sufficiently large:
TIMEOUT > T CI,F_SEND + T CI,F_RCV + MAX(TDelay,F_SEND; TDelay,F_RCV)
+ 2 ☓ TUSEND + MAX(MIN(TCiR,F_SEND; 2500);MIN(TCiR,F_RCV; 2500))
Use the greater of the two values
1
Definition of Times
Time
TCI,F_SEND
TCI,F_RCV
TDelay,F_SEND
TDelay,F_RCV
TUSEND
TCiR,F_SEND
TCiR,F_RCV
Safety Engineering in SIMATIC S7
System Manual, 04/2006, A5E00109529-05
A.4 F-Related Monitoring Times for S7 F/FH Systems
the same
monitoring time, which must be assigned in
Definition
Configured cycle time of the time
interrupt OB with the call of F_SENDBO
or F_SENDR
Configured cycle time of the time
interrupt OB with the call of F_RCVBO or
F_RCVR
Maximum communication delay when
updating the reserve in the
FH System with the call of F_SENDBO or
F_SENDR
Maximum communication delay when
updating the reserve in the FH System
with the call of F_RCVBO or F_RCVR
Maximum response time of USEND
With 48 bytes of user data for
•
F_SENDBO
With 88 bytes of user data for
•
F_SENDR
CiR synchronization time of the F-CPU
with the call of F_SENDBO or F_SENDR:
Sum of CiR synchronization times for all
DP master systems that are to be
changed simultaneously.
CiR synchronization time of the F-CPU
with the call of F_RCVBO or F_RCVR:
Sum of CiR synchronization times for all
DP master systems that are to be
changed simultaneously.
Monitoring and Response Times of F-Systems
Reference
In
HW Config
: Object properties for
CPU, "Time interrupt, Type"
In
HW Config
: Object properties for
CPU, "Time interrupt, Type"
HW Config
In
sender CPU, "H-parameters" tab
HW Config
In
receiver CPU, "H-parameters" tab
Refer to the Internet for information
(see below)
HW Config
In
CiR object
If CiR is not used, enter "0" in the
formulas
HW Config
In
CiR object
If CiR is not used, enter "0" in the
formulas
both
1
1
: Object properties for
: Object properties for
: Object properties for
: Object properties for
A-13