Safety engineering
Response times
Response time of encoder monitoring
70
EDS94AYAF EN 1.0
Information on how to calculate the processing time and transmission time of the safety
bus can be found in the documentation of the safety PLC used.
Note!
When the safety bus communication is disturbed, it is changed to the fail−safe
state after the safety bus monitoring time (F_WD_Time) has elapsed. The
safety bus communication is passivated.
Example
ƒ
After an event has occurred at a safe input, the message is fed back to drive−based
safety via the safety PLC.
ƒ
Drive−based safety activates a safety function.
ƒ
Hence, the maximum response time to the event is calculated as follows:
t
max response
= t
1
+ t
2
+ t
3
+ max {t
WD
; t
PS
+ t
4
+ t
Ps
+ t
5
}
When calculating the maximum response time, include the times of the safety functions,
e.g. in case of SS1 the stopping time (C15305) until STO is active.
1.8.4
Response time of encoder monitoring
Response time of encoder monitoring
[ms]
Time required to detect
faults caused by continuous
signal errors at the encoder
interface.
12
can be parameterised under
C15410
12/50/100
Note!
The minimum response time must be individually determined for each system.
A longer response time leads to an increased system availability, if, for
instance, during machine set−up with safe operating stop process−related
speed jumps occur for a short time.