IFM Electronic AC402S Programming Manual page 98

SmartPLC SafeLine AC4S with fieldbus interfaces
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Step 4: Calculate the worst-case response time of the safety function
The worst-case process safety time
► Calculate the worst case on the basis of the calculated and measured values.

Without safe cross communication:
-
AS-i input
-
Local input
T(WD_FSoE) +
FSoE slave
2*T(SafetyTask) +
input
15 ms

With safe cross communication:
From device 1
MAX(
AS-i input
30 ms +
2*T(SafetyTask_Dev1) +
tMaxRespTimeMS(SafetyNetVars)
+ 2*T(SafetyTask_Dev2) +
15 ms;
T(WD_SafetyNetVars) +
2*T(SafetyTask_Dev2) +
15 ms)
MAX(
Local input
16 ms +
2*T(SafetyTask_Dev1) +
tMaxRespTimeMS(SafetyNetVars)
+ 2*T(SafetyTask_Dev2) +
15 ms;
T(WD_SafetyNetVars) +
2*T(SafetyTask_Dev2) +
15 ms)
MAX(
FSoE slave
T(WD_FSoE_in) +
input
2*T(SafetyTask_Dev1) +
tMaxRespTimeMS(SafetyNetVars)
+ 2*T(SafetyTask_Dev2) +
15 ms;
T(WD_SafetyNetVars) +
2*T(SafetyTask_Dev2) +
15 ms)
The response times of the output side have to be added to the calculated worst-case times
(T(output) + T(actuator)).
98
AS-i output
-
-
T(WD_FSoE) +
2*T(SafetyTask) +
8 ms
AS-i output
MAX(
30 ms +
2*T(SafetyTask_Dev1) +
tMaxRespTimeMS(SafetyNetVars)
+ 2*T(SafetyTask_Dev2) +
8 ms;
T(WD_SafetyNetVars) +
2*T(SafetyTask_Dev2) +
8 ms)
MAX(
16 ms +
2*T(SafetyTask_Dev1) +
tMaxRespTimeMS(SafetyNetVars)
+ 2*T(SafetyTask_Dev2) +
8 ms;
T(WD_SafetyNetVars) +
2*T(SafetyTask_Dev2) +
8 ms)
MAX(
T(WD_FSoE_in) +
2*T(SafetyTask_Dev1) +
tMaxRespTimeMS(SafetyNetVars)
+ 2*T(SafetyTask_Dev2) +
8 ms;
T(WD_SafetyNetVars) +
2*T(SafetyTask_Dev2) +
8 ms)
Local output
T(WD_FSoE)
T(WD_FSoE)
T(WD_FSoE_in) +
2*T(SafetyTask) +
2*tMaxRespTimeMS(FSoE_out)
To device 2
Local output
MAX(
30 ms +
2*T(SafetyTask_Dev1) +
tMaxRespTimeMS(SafetyNetVars)
+ 2*T(SafetyTask_Dev2) +
tMaxRespTimeMS(FSoE_out);
T(WD_SafetyNetVars) +
2*T(SafetyTask_Dev2) +
tMaxRespTimeMS(FSoE_out);
T(WD_FSoE_out))
MAX(
16 ms +
2*T(SafetyTask_Dev1) +
tMaxRespTimeMS(SafetyNetVars)
+ 2*T(SafetyTask_Dev2) +
tMaxRespTimeMS(FSoE_out);
T(WD_SafetyNetVars) +
2*T(SafetyTask_Dev2) +
tMaxRespTimeMS(FSoE_out);
T(WD_FSoE_out))
MAX(
T(WD_FSoE_in) +
2*T(SafetyTask_Dev1) +
tMaxRespTimeMS(SafetyNetVars)
+ 2*T(SafetyTask_Dev2) +
tMaxRespTimeMS(FSoE_out);
T(WD_SafetyNetVars) +
2*T(SafetyTask_Dev2) +
tMaxRespTimeMS(FSoE_out);
T(WD_FSoE_out))
43029
FSoE slave output
FSoE slave output