134 HB700 | CPU | PMC921xEx | en | 24-04
Deployment CPU iC921xM-FSoE
Response times > Cycle monitoring time T
CL_MAX
safety CPU
Dimensioning
Dimensioning
Dimensioning
5.12.4 Maximum permitted watchdog times
The following formula applies for dimensioning TI/TO
FSoEWD_MAX
in the FSoE system:
TI
FSoEWD_MAX
+ T
O
FSoEWD_MAX
≤ T
maxRTSA
- TI
WCDT
- TO
WCDT
⮫‘Designations’
...page 135
TI/TO
FSoEWD_MAX
Maximum permitted FSoE watchdog time
(FSoE WatchDog MAXimum).
T
maxRTSA
Max. response time on error with max. runtime with sensor and
actuator (max RunTime Sensor Actuator).
TI/TO
WCDT
Max. response time without errors (Worst Case Delay Time).
Based on the information in the device-specific user documentation of
the F devices, consider whether further information on watchdog times is
available within the internal device function.
Timer functions that are used in the safety-related application programme
within the safety function must also be taken into account for the calcula-
tion.
You can find more information on calculating and optimizing the watchdog
time in the documentation of the iCube Engineer.
5.12.5 Cycle time T
CL
safety CPU
iCube Engineer
:
The following formula applies to the cycle time:
T
CL
= T
FPROG
/ 0.7
T
FPROG
is to be estimated. The following specifications for totalization apply:
■ Add 70µs per F device.
■ Add 20µs per safety-related function block instances.
In
iCube Engineer, the value is to be specified at ‘Plant 🠂 Safety PLC’: ‘Tasks and Events
🠂 Intervall’ in the range of 5 ... 15ms.
⮫‘Designations’...page 135
T
CL
Cycle time of the safety CPU.
T
FPROG
Cycle time safety program.
5.12.6 Cycle monitoring time T
CL_MAX
safety CPU
The following formula applies to the cycle monitoring time:
T
CL_MAX
≥ T
FPROG
/ 0.7
T
FPROG
is to be estimated. The following specifications for totalization apply:
■ Add 70µs per F device.
■ Add 20µs per safety-related function block instances.
In iCube Engineer
, the value is to be specified at ‘Plant 🠂 Safety PLC’: ‘Tasks and Events
🠂 Watchdog’.
⮫‘Designations’...page 135
T
CL_MAX
Cycle monitoring time of the safety CPU.
T
FPROG
Cycle time safety program.