Datalogic SG4 BASE - Minimum Installation Distance

SG4 BASE
11/73
1.4.3 Minimum installation distance
The safety device must be positioned at a specific safety distance (Fig 3 - page 11).
This distance must ensure that the dangerous area cannot be reached before the dangerous motion of the
machine has been stopped by the Safety Control System.
The safety distance depends on 4 factors, according to the EN ISO 13855 Standard:
• Response time of the ESPE (the time between the effective beam interruption and the opening of the OSSD
contacts)
• Machine stopping time including Safety Control System computing and actuating time if present.
• ESPE resolution
• Approaching speed of the object to be detected
Fig 3 - Installation distance (vertical positioning)
The following formula is used for the calculation of the safety distance:
S = K (t1 + t2) + C
where:
S = Minimum safet
y
distance in mm
K = Speed of the ob
j
ect, limb or bod
y
approachin
g
the dan
g
erous area in mm/sec
t1 = Response time of the ESPE in seconds
(
see cfr.TECHNICAL DATA pa
g
e 48
)
t2 = Machine stoppin
g
time in seconds
(
includin
g
the Safet
y
Control S
y
stem
)
C = Additional distance based on the possibility to insert the body or one of body parts inside
the dan
g
erous area before the protective device trips.
C=8
(
R -14
)
for devices with resolution ≤ 40 mm
C=850 mm for devices with resolution > 40 mm
R = Resolution of the s
y
stem
K value is:
2000 mm/s if the calculated value of S is ≤ 500 mm
1600 mm/s if the calculated value of S is > 500 mm