SICK deTec4 Ex II 3GD - Page 29

NOTE
If t
he safety light curtain is configured with a reduced resolution, then the minimum
distance must be calculated according to the effective resolution in accordance with
ISO 13855.
If the effective resolution is > 40 mm, a different formula may have to be used for the
calculation of the minimum distance.
Approach
T
he example shows the calculation of the minimum distance in accordance with ISO
13855 for an orthogonal (right-angled) approach to the protective field. A different
calculation may be required depending on the application and the ambient conditions
(e.g., for a protective field parallel to or at any angle to the direction of approach or an
indirect approach).
1. First, calculate S using the following formula:
S = 2,000 mm/s × T + 8 ×(d – 14 mm)
Where:
°
S = minimum dis
tance in millimeters (mm)
°
T = machine stopping time + response time of the protective device after
interruption in the light path in seconds (s)
°
d = resolution of the safety light curtain in millimeters (mm)
The reach or approach speed is already included in the formula.
2. If the result S is ≤ 500 mm, then use the determined value as the minimum
dis
tance.
3. If the result S is > 500 mm, then recalculate S as follows:
S = 1,600 mm/s × T + 8 ×(d – 14 mm)
4. If the new value S is > 500 mm, then use the newly determined value as the
minimum distance.
5. If the new value S is ≤ 500 mm, then use 500 mm.
!
"
§
S
Figure 11: Minimum distance to the hazardous point for orthogonal (rectangular) approach to the
pr
otective field
!
Protective field height
"
Hazardous point
§
Depending on the application and distance, persons must be prevented from standing
behind the protective device.
PROJECT PLANNING 4
8023872/18YZ/2021-01-14 | SICK O P E R A T I N G I N S T R U C T I O N S | deTec4 Ex II 3GD
29
Subject to change without notice