5
Notes on implementing the process images
Safety-related cut-off paths and non-safety-related cut-off paths
In the following example, cut-off paths 1 (protective field) and 4 (contour detection field)
are safety-related. Cut-off paths 2 and 3 (warning fields) are non-safety-related.
When incorporating the cut-off paths into the logic, the user can select a suitable byte
from the assembly. A cut-off path with a protective field or contour detection field is
always regarded as safety-related. A cut-off path with a warning field is always regarded
as non-safety-related.
Table 7: Example 6-byte process image
Function
(Safety Designer)
Field type
Allocation in the
process image
Data
Safe
Cut-off path 1
Protective field
Safety-related cut-off
path 1
I1.0
Yes
Cut-off path 2
Warning field
Non-safety-related
cut-off path 2
I2.1
No
Cut-off path 3
Warning field
Non-safety-related
cut-off path 3
I2.2
No
Cut-off path 4
Contour detection
field
Safety-related cut-off
path 4
I1.3
Yes
Behavior with mixed field types
When a cut-off path with safe and non-safe fields (e.g., protective field and warning
field) is used in different monitoring cases and the monitoring case with the warning
field is active, then the safe cut-off path is deactivated. As a result, the bit for this safe
cut-off path is LOW and the display of the safety laser scanner indicates the OFF state.
The following example illustrates this behavior in the configuration and in the display of
the device. All fields are clear in this example (no field detection).
5
NOTES ON IMPLEMENTING THE PROCESS IMAGES
16
T E C H N I C A L I N F O R M A T I O N | microScan3 - PROFINET
8026545/2021-03-15 | SICK
Subject to change without notice
