Duration of the monitoring case switching
If an object has been detected in a non-active protective or warning field, the safe
multibeam scanner can process the corresponding result immediately after the moni‐
toring case is switched. In this case you need to take into account the time required to
perform the monitoring case switching.
t
CSR
= 20 ms + 2 x t
CANtransmission
Where
•
t
CSR
= Duration of monitoring case switching in milliseconds (ms)
•
t
CANtransmission
= Time for the CAN transmission of the PDO/SRDO in milliseconds
t
CANtransmission
depends on the following configuration settings:
•
Configured baud rate
•
CAN bus load
•
For PDO: transmission type (event-driven or synchronous)
•
For PDO: configured inhibit time
•
For SRDO: configured refresh time / safeguard cycle time (SCT)
Compare the time required to perform the monitoring case switching with the response
time (
) of the safe multibeam scanner. If the response
time is exceeded, check whether your application requires countermeasures. For exam‐
ple, you can initiate switching earlier or reduce the vehicle speed in the case of mobile
hazardous area protection.
When specifying the time of monitoring case switching, also take into account the
signal propagation times to the safe multibeam scanner, e.g. the processing time of a
control.
4.3.5
Distance from walls
The availability may be impaired if the protective field stretches as far as a wall or a
different object. So, a space between the protective field and the object is required. A
distance of the TZ value is recommended to ensure availability. (TZ = tolerance zone of
the safe multibeam scanner,
!
Figure 10: Distance of the protective field from the wall
1
Recommended distance of the protective field from the wall.
PROJECT PLANNING
4
8025990/2021-03-03 | SICK
O P E R A T I N G I N S T R U C T I O N S | scanGrid2 CANopen
21
Subject to change without notice
