t
Uv
1
t
U
Δt
2
3
5
4
Figure 32: Advancing the switching time (example)
The gantry robot
1
moves to the right
2
. The dangerous movement is being monitored
on the left-hand side by one of the monitoring cases
3
. Due to the required advance‐
ment of the switching time, it is necessary to already switch the monitoring case when
the gantry robot arrives at the point t
Uv
to ensure that the right monitoring case
4
is
active at time t
U
.
The same applies for a movement to the left, i.e., for the switchover to monitoring case
3
.
The protective fields of the monitoring cases must overlap
5
to ensure the protective
function is guaranteed at all times.
Time of switching
Calculating the time of switching
•
The time of switching is calculated using the following equation:
t
UFVz
= t
EVz
+ t
exOVz
+ t
StVz
where
•
t
UFVz
= time by which the switching is advanced
•
t
EVz
= input delay for the control inputs
•
t
exOVz
= delay time due to external OSSDs via EFI = 20 ms
•
t
StVz
= delay time due to external control inputs via EFI (0.5 × basic response time
of the slowest system in the EFI system)
Complementary information
•
In the phases before and after switching, only the minimum distances calculated
for the individual monitoring cases apply.
•
The preceding considerations are provided exclusively for the purposes of select‐
ing the optimum switching time.
4
PROJECT PLANNING
40
O P E R A T I N G I N S T R U C T I O N S | S3000
8009942/ZA18/2019-11-14 | SICK
Subject to change without notice
