2
Description of the safety function STO
20
Festo – GDCP-CMMS-AS-G2-S1-EN – 1306NH – English
2.3.4
STO timing diagram
Controller enable
DIN5 [X1.9]
Output stage
enable DIN4
[X1.21]
Actual speed
value
Output stage
active
Open holding
brake BR+ [X6.2]
Holding brake
open (mechanical)
t1
7-segment display
t3
t5
t2
Acknowledgment
contact NC1/NC2
[X3.5/6]
Driver supply relay
Rel [X3.2]
t4
Safe Torque Off
t5
‘H’
t4
t8
t7
t6
t10
t9
Open
Closed
Open
t
STO
t1
≤
5 ms
t2
≤
2.5 ms
t
STO
≤
12 ms
t3
L
50 … 500 ms (dependent on the brake
used)
t4
≤
30 ms
t5
≤
720 ms
t6
≤
20ms
t7
any
t8
>
2.5 ms
t9
≤
5 ms (For control via the fieldbus,
controller enable via fieldbus is also required
beforehand)
t10 0 … 6553 ms (with FCT parameterised
switch-on delay brake)
Fig. 2.4
STO timing diagram