Datalogic SG4 FIELDBUS Series, Instruction Manual, Page: 17 / 136

HOW TO CHOOSE THE DEVICE
INSTRUCTION MANUAL 7
When devices with > 40 mm resolution are used, the height of the top beam has to be ≥
900 mm (H2) from machine supporting base while the height of the bottom beam has
to be
≤ 300 mm (H1).
If the safety light curtain must be mounted in a horizontal position (Figure 4) the dis-
tance between the dangerous area and the most distant optical beam must be equal to
the value calculated using the following formula:
S = 1600 mm/s (t1 + t2) + 1200 - 0.4 H
where:
• S = Minimum safety distance in mm
• t1 = Response time of the ESPE in seconds (see "
Technical Data" on page 83
)
• t2 = Machine stopping time in seconds (including the Safety Control System)
• H = Beam height from ground; this height must always be less than 1,000 mm
Figure 4 - Installation distance (horizontal positioning)
Practical examples
Let's suppose to have a light curtain with height = 600 mm
To calculate the distance of the device from the ESPE, in a vertical position, the follow-
ing formula is used:
S = K*T + C
where:
• S = Minimum safety distance in mm
• t1 = ESPE response time
• t2 = Machine stopping time (including the Safety Control System)
• T = (t1 +t2) Overall system stopping performance
• C = 8 * (R - 14) for devices with resolution ≤ 40 mm
• R = Resolution of the system
In all cases, if K = 2000 mm/s, then S > 500 mm.
Distance will have to be recalculated using K = 1600 mm/s.
NOTE
The reference standard is EN ISO 13855 “Safety of machinery - Positioning
of safeguards with respect to the approach speeds of parts of the human
body”.
The following information is to be considered as indicative and concise.
For correct safety distance please refer to complete standard EN ISO
13855.