Lenze SM302 - Page 47

Safety engineering
Safety functions
Safe maximum speed
1

47
EDS94AYAF EN 1.0
t
t
t
t
STO
SLS

0
0
0
I
I
I
2
t
R
t
S
t
C
t1 t3t2
n
SM301DIA_F
T1 Occurrence of the error event
t
C
Cycle time 2 ms
T2 Determining the error event
t
R
Maximum permissible response time (parameterisable)
t3 Response instance to continuous exceedance
t
S
Stopping time
 Feedback(s)
SLS SLS monitored
 According to the error response set: SS2, SS1 or STO
STO Response in case of an error after the max. response time has elapsed
–––– Normal operation
−−−−−− Incorrect operation
 Note!
If the STO function has been selected as the error response for SMS or SLS, the
internal response time is not considered because the motor is already coasting
after the speed threshold is exceeded for the first time.
 Note!
In case of an error, the set limited speed will be exceeded.
To assess the risk for the plant, you have to calculate the height of the
maximum exceedance. Consider the following:
ƒ internal response time
ƒ application−specific response time
ƒ application−specific maximum acceleration