5
EN
SLC 425I
Operating instructions
Safety light curtain
2.8.6 Blanking
Fixed blanking
The SLC 425 I can blank stationary parts in the protection field.
Multiple protection field areas can be blanked. If small changes are
made within the fixed blanking area, each time 1 beam can be additi-
onnally blanked to increase the tolerance.
Fixed blanking area
E1
R1
The range of the fixed blanking can be arbitrarily chosen in the protec-
tion field.
The first beam line, which realises the optical synchronisation and is
located immediately behind the diagnostic window, cannot be blanked.
The area of the fixed blanking must not be modified after the teach-in
process. Any change of the area or removal of the part from the pro-
tection field will be detected by the system. As a result, the outputs are
disabled (locked). This locking can be neutralised by executing a new
teach-in process in accordance with the actual beam interruptions.
• The remaining lateral areas must be protected against intru-
sion by means of mechanical covers.
• The lateral covers must be fixed with the object. Partial
covers are not authorised.
• After the fixed blanking, the protection field must be tested
by means of the test rod.
• The restart interlock function of the safety light curtain or the
machine must be activated.
The standard IEC/TS 62046 includes information, which
describes possibly required additional measures to prevent a
person from reaching a hazard through the blanking areas of
a protection field.
The function is activated by means of the NSR-0801 BUS
converter and a PC or laptop. The activation of the function
is signaled by the LED blanking flashing in the diagnostic
window of the receiver.
Floating blanking
The SLC 425 I can blank movable parts in the protection field.
Cylinder for material ejection
The function enables an arbitrary floating blanking of partial areas in the
protection field.
The first beam, which is located immediately behind the diagnostic
window, cannot be blanked.
The SLC 425I can blank one or more beams in the protection field. A
combination of fixed and variable blanking is possible.
This function allows for an interruption of the protection height without
the outputs being disabled in case of material movement in the protec-
tion field, e.g. material ejection or process-controlled material move-
ment. This extension of the object detection increases the resolution.
In this way, the physical resolution changes into an effective resolution.
This effective resolution must be used to calculate the safety distance.
This effective resolution must be used to calculate the safety distance.
Calculation of the safety distance in accordance with the effective
resolution for the blanking of a maximum of 2 beams by means of for-
mula (1), in case of more than 2 beams by means of formula (3) of the
chapter “Determination of the safety distance”
The number of beams to be blanked is limited by the software.
In a system with a 14 mm physical resolution, the effective resolution
is increased to 2 mm in case of a variable blanking of 34 beams. The
effective resolution must be registered permanently and clearly visible
onto the label affixed to the receiver.
Effective resolution
The effective resolution in case of activated blanking of floating beams
can be found in the following table:
Beams
blanked
Physical
Resolution
Effective
resolution
1
14
24
2
14
34
3
14
44
4
14
54
5
14
64
6
14
74
7
14
84
8
14
94
Beams
blanked
Physical
Resolution
Effective
resolution
1
30
45
2
30
65
3
30
85
4
30
105
The function is activated by means of the NSR-0801 BUS
converter and a PC or laptop. The activation of the function
is signaled by the LED blanking flashing in the diagnostic
window of the receiver.
The function is activated by means of the NSR-0801 BUS
converter and a PC or laptop. The activation of the function
is signaled by the LED blanking flashing in the diagnostic
window of the receiver.
The function "mobile blanking" is not available in the opera-
ting mode muting.
Perform a new calculation of the safety distance with the
effective resolution.
Adjust the safety distance in accordance with your calculation!
After configuration, the protection field must be checked by a
responsible person by means of a test rod; in addition to that,
this person must compare the size of the blanked area to the
object size and if necessary provide for additional covers or a
larger distance of the safety guard with regard to the hazar-
dous point. The standard IEC/TS 62046 includes information,
which describes possibly required additional measures to pre-
vent a person from reaching a hazard through the blanking
areas of a protection field.
