Rockwell Automation 442L SafeShield Safety Light Curtain Hardware User Manual

Page 18

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SafeShield Safety Light Curtain Hardware User Manual

18

Table 9: Types of object monitoring for floating blanking

Notes Directly adjacent to the area with floating blanking with

partial object monitoring you can only configure areas
with fixed blanking.

During operation an area with floating blanking with
partial object monitoring is allowed to overlap with an
area of fixed blanking without positional tolerance.

➢ After modifying the blanking, check the protective field with the

test rod. Instructions can be found in the “Daily Functional
Checks of the Protective Device” on page 31.

➢ Also pay attention to the warnings in the related chapter.

Effective Resolution for Blanking

The effective resolution of an optical system depends on both its
optical components and on its configuration. The effective
resolution cannot be higher than the highest possible physical
resolution of the system. However, it can be reduced by the
configuration, e.g. by blanking beams.

In conjunction with size tolerance, the effective resolution is
reduced at the edges of the blanked areas. For blanking with size
tolerance, the effective resolution depends on the physical
resolution and the size tolerance chosen.

Object
monitoring

Description

Complete

The blanked area must be completely covered by the
object within the size tolerance. If this is not the case, then
the safety light curtain switches to red.

Partial

The blanked area does not need to be covered by an
object. However within the size tolerance it can be
partially or completely covered. If you have configured
several areas with floating blanking, then only one area can
use this setting.

ATTENTION:

Check the safety

distance!

When using floating blanking with increased
size tolerance, the required safety distance
will depend on the effective resolution (see
Table 10).

If required, recalculate the safety distance
and readjust it on the machine.

Example: – physical resolution 14mm

– size tolerance –2 beams
– effective resolution 22mm
Calculate the safety distance
with a resolution of 22mm

Mark the effective resolution on the
information label “Operation with blanking
combined with size tolerance …” on the
related sender and receiver.

Figure 15: Marking the effective resolution on the device label

Table 10: Effective resolution for blanking with size tolerance

For floating blanking with partial object monitoring and for fixed
blanking with increased size tolerance, a hole is produced in the
protective field for technical reasons. With the aid of Table 11 you
can determine the effective resolution of the safety light curtain at
this point and the minimum size of an object to ensure that the
safety light curtain reliably switches to red.

Table 11: Effective resolution for floating blanking with partial object
monitoring and for fixed blanking with increased size tolerance

Mark the effective resolution on the information label “Operation
with reduced resolution or blanking …” on the related sender and
receiver.

Resolution modified
to: (please mark)

Physical resolution

14mm

30mm

Size Tolerance

Effective Resolution

1 beam

14mm

40mm

2 beams

22mm

Not
possible

Physical

Resolution

Size

Tolerance

Effective Resolution

at the Edges of the

Blanked Area

Permissible

Types of

Blanking

14mm

Without

14mm

Fixed

–1 beam

14mm

Fixed and floating

–2 beams

22mm

Floating

30mm

Without

30mm

Fixed

–1 beam

40mm (no PSDI mode) Fixed and floating

–2 beams

Not permitted

Not permitted

Physical

resolution

Size of the

blanked area

Blanked beams

(= reduction)

Effective

resolution/

size of the hole

14mm

7.5mm

1 beam

22mm

15mm

2 beams

30mm

22.5mm

3 beams

37mm

n × 7.5mm

n beams

(n + 2) × 7.5mm

30mm

20mm

1 beam

50mm

40mm

2 beams

70mm

60mm

3 beams

90mm

n × 20mm

n beams

n × 20mm + 30mm

ATTENTION: During operation with
“Blanking” combined with “Size
tolerance,” the safety distance that
corresponds to the modified resolution is
to be observed.

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