Rockwell Automation 440L GuardShield Type 4 and Remote Teach User Manual - Manual (Page 13)

R
GuardShield™ Safety Light Curtain User Manual
11
Original instructions
If the result S is > 500 mm (19.6 in.), then recalculate S as
follows:
S = 1600 × T + 8 × (d – 14) [mm]
If the new value S is > 500 mm (19.6 in.), then use the newly
determined value as the minimum safety distance.
If the new value S is ≤ 500 mm (19.6 in.), then use 500 mm
(19.6 in.) as the safety distance.
Example:
Stopping/run-down time of the machine = 290 ms
Response time = 30 ms
Resolution of the light curtain = 14 mm (0.55 in.)
T = 290 ms + 30 ms = 320 ms = 0.32 s
S = 2000 Ч 0.32 + 8 Ч (14 – 14) = 640 mm (25.1 in.)
S > 500 mm, therefore:
S = 1600 Ч 0.32 + 8 Ч (14 – 14) = 512 mm (20.1 in.)
Example:
In opto-electronic safeguarding, such as with a perpendicular safety
light curtain applications with object sensitivity (effective resolution)
less than 2.5 inches, the D
pf can be approximated based on the
following formula:
D pf (inches) =3.4 × (Object Sensitivity – 0.276),
but not less than 0.
Minimum Distance from Reflecting Surfaces
The infrared light from the sender may be reflected off of shiny
surfaces and be received by the system’s receiver. If this condition
occurs, it can result in an object not being detected when it enters the
GuardShield sensing field.
All reflecting surfaces and objects (e.g. material bins) must therefore be
located at a minimum distance
a from the protective field of the
system. The minimum distance
a depends on the distance D between
sender and receiver.
Figure 5: Minimum distance from reflecting surfaces
How to Determine the Minimum Distance from the
Reflecting Surfaces:
Determine the distance D [m] sender-receiver
Read the minimum distance a [mm] from the graph:
Figure 6: Graph, minimum distance from reflecting surfaces
The effective aperture angle for the GuardShield system is
+/- 2.5° at a mounting distance of > 3.0 m (9.8 ft). Calculate the
minimum distance to reflecting surfaces depending on the distance
between the transmitter and the receiver, using an aperture angle of +/
- 2.5°, or take the appropriate value from the following table:
Note: Formula: a = tan 2.5° x D [mm]
a = minimum distance to reflecting surfaces
D = distance between transmitter and receiver
Installation and Mounting
This section describes the preparation, selection and installation of the
GuardShield safety light curtain.
The standard GuardShield has an amber LED in the receiver which is
used as an alignment aid. This LED will begin flashing when the
infrared light from the transmitter is “seen” by the receiver. This LED
turns off when optimal alignment is attained.
Alignment Procedure: Standard GuardShield
Mount and connect both transmitter and receiver. They must be
parallel to each other and be positioned at the same height.
Turn on power to GuardShield system.
Rotate the transmitter while watching the amber LED on the receiver
to find the point where the indicator for the ON state (Green LED)
illuminates and the amber LED goes off.
Determine the maximum left and right turning angles and position
unit in center. Tighten all hardware assuring that the alignment
indicator is not illuminated.
a
Distance D (meters)
Distance Between Transmitter and Receiver
(Range L) [m (ft)]
Minimum Distance
a [mm (in.)]
0.2 to 3.0 (0.65 to 9.8) 135 (5.31)
4.0 (13.1) 175 (6.88)
5.0 (16.4) 220 (8.66)
6.0 (19.6) 265 (10.43)
7.0 (22.9) 310 (12.2)
10.0 (32.8) 440 (17.32)
16.0 (52.4) 700 (27.55)