Siemens SIMATIC PCS 7 Operating Manual page 159

Other parameters
The remaining parameters have been discussed in the preceding sections of this section.
Processing in the 1st CPU / processing in the 2nd CPU
The processing in the 2nd CPU is optional. It involves the same variants as in the 1st. CPU.
There are 2 different variants:
● One F-shutdown group is present in the signal flow being examined.
● Two F-shutdown groups are present in the signal flow being examined.
You will need the following parameters for the calculation:
T /T
CI
T
CImax.proj.
T
CI max.proj.2
T
FPROG
TIMEOUT
CPU-to-CPU communication (optional)
If your signal is transferred from one CPU to another, select "Yes" in the header. For
calculation purposes, you require the time parameterized at the TIMEOUT input of the send
and receive blocks for communication.
If CPU-to-CPU communication is not taking place, leave the default setting ("No")
unchanged. The next section, "Processing in the 2nd CPU", is not be taken into account
during calculation in this case
Result
As the result, S7ftimea.xls returns two groups with 3 times each.
The lower group takes into account the delay times of the sensor and actuator.
Check that the times calculated meet the requirements of your process.
Compendium Part B - Process Safety (V8.2)
Operating Manual, 07/2016, A5E35031794-AB
/T Configured cycle time of the cyclic interrupt OB in which the F-function
CI1 CI2
block has been installed in each case
/ T / Time set in chart @F_CycCo-OBxx, at input MAX_CYC of the
CImax.proj.1
F_CYC_CO-OBxx F-function block (xx = Number of corresponding cyclic
interrupt OB).
/T /T Program runtime of the corresponding cyclic interrupt OB
FPROG1 FPROG2
Time parameterized at the TIMEOUT input of the F_R_BO or F_R_R
block
Configuring the safety program
7.11 Monitoring times and system response times
159