Rockwell Automation MSR42 Curtains Configuration and Diagnostic Software Tool User Manual - Manual (Page 54)

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Light Curtain Multi-Function Control Module User Manual
Original instructions
Important safety notice:
Additionally, the blanked region should be clearly marked, and the protective field should be fully tested with the provided test rods according to the
instructions given in the MSR42 user manual. The user should ensure that the number of blanked beams (i.e. the size of the object interrupting the
protective field) will not be reduced during operation. If this is not possible, there is a risk that the resolution, at the edge of the “Fixed Blanking” area
will be increased by 10 mm for a light curtain with 14 mm resolution and 25mm for a light curtain with 30mm resolution. This must be considered
when calculating the safety distance.
5.7.3. Floating Blanking mode
Floating Blanking is understood to be an interruption of a certain number of beams (adjacent) anywhere in the protective field. The specified number of
interrupted beams may not be exceeded. If they are exceeded the MSR42 safety output will switch off. The blanked area(s) may move throughout a
defined region of the light curtain. The remaining beams within this region maintain their normal safety operation.
According to safety regulations, two floating Blanking modes are permitted: "with monitoring" and "without monitoring".
"With monitoring" means that the specified number of interrupted beams must be located next to each other and are always interrupted. If they are not
interrupted the MSR42 safety output will switch off. Due to vibrations often present in industrial applications, the number of physically interrupted
beams in this mode is allowed to be 1 less than the specified number of beams. A local adjustment of this “tolerance” value is not possible (
Table 5).
"Without monitoring" means that the specified number of interrupted beams may be interrupted, but do not have to be. For Floating Blanking
“without monitoring”, the specified number of interrupted beams do not have to be located next to each other.
Example:
A Micro 400 light curtain has 60 beams, which for a 14 mm resolution light curtain, means 600 mm protective height. In one application with
monitoring, an object must interrupt six adjacent beams, somewhere within the specified protective field region. The process requires that the object
interrupting the light beams, can move around throughout the protective field. At one point in time, beams 10 to 15 are interrupted, and at another
point in time, beams 20 to 25 are interrupted. Due to this movement, Fixed Blanking is not acceptable.
If in this example, if beams 10 to 15 and beam 20 were interrupted, this would not be permitted and the MSR42 safety output will switch off.
The following condition would also not be allowed:
• Beam 10 to 12 interrupted
• Beam 13 not interrupted
• Beam 14 to 15 interrupted
This is because the interrupted beams are not adjacent to each other.
Typical application examples for "Floating Blanking" are applications where the transport of material occurs between the working area and the
dangerous area, e.g. a roll of metal sheeting that is fed into a punch press, and depending on the position of the roll will interrupt a different area of the
protective field (
Figure 72).
Figure 72: Typical application of "Floating Blanking" with "monitoring"
Important safety notice:
During "Floating Blanking without monitoring", protective field "holes" can occur. This means at times when no material or insufficient material is being
transported through the protective field, there is a danger that the operator can reach through the protective field without deactivating the machine.