How miniature safety laser scanners can maximize protection and productivity
designed to mitigate risks that could result in serious injuries or significant environmental damage, but not necessarily catastrophic events. Using similar concepts to SILs, ISO 13849 defines performance levels (PLs). Safety mats typically qualify for a PLc certification, while safety laser scanners must qualify for the tougher PLd certification. Some safety mat installations can also meet PLd performance requirements. To become certified, a safety laser scanner must meet SIL 2, PLd, and IEC 61496-3, specifically covering active optoelectronic protective devices responsive to diffuse reflection (AOPDDR, or laser scanners). The implications of the various safety certifications for safety mats and safety laser scanners are important, but they are just the start when maximizing protection and productivity. More to consider Properly specified safety mats and safety laser scanners can both meet the IEC and ISO safety requirements. But that’s not the end of the story; there’s more to consider in Industry 4.0 factory and logistics automation applications. A safety mat is a matrix of mechanical switches. When a weight, like a person stepping on the mat, closes one or more of
Figure 1: Safety mat operation requires physical contact and can be compromised by accidents and environmental hazards. (Image source: SICK)
the switches, it sends a signal to the mat controller that stops the operation of the protected system. The mechanical nature of safety mats can be a cause for concern. First, for the mat to operate, there must be direct contact with a person walking across the mat. Second, the mats are subjected to wear and (sometimes literally) tear. People can drop heavy and/or sharp tools on the mat, damaging it (Figure 1). Or a forklift may drive across the mat and damage it. Environmental factors like spills of corrosive materials can also compromise the mat.
There are different sizes and mat configurations for specific installation requirements. That can present challenges in Industry 4.0 factories and logistics operations that are subject to reconfiguration as process demands change. Making changes to safety mat- based systems can require the acquisition of a new mat, extending the time needed for the changeover to become operational. That can negatively impact machine availability and overall productivity. One way to minimize the impact is to keep various replacement safety mat sizes on hand. That can speed changeovers and the replacement of mats that become damaged. But it’s also expensive. It can also require keeping a variety of safety mat
Adjustability
Safety mats are inherently fixed installations and are not adjustable.
12
Powered by FlippingBook