This is an excerpt from the May/June 2013 InTech by John D’Silva. To read the full article, please see the link at the bottom of this post.
Machine builders and end users can now enjoy the benefits of new machine guarding technologies endorsed by international safety standards. From the most sophisticated manufacturing operation to the simplest relay-based system, economical and effective choices are now available to enhance machine safety. In the 1970s, machine builders 
began to change the way they wired machines by replacing relays with automatic sequencers, known today as programmable logic controllers (PLC). However, machine builders addressed safety as an afterthought. Regulators excluded PLCs from machine safety, and little attention was paid to safety by end users.
Today it is a different story.
It is no longer necessary to attach steel cables to operators’ wrists to keep hands out of machine pinch points, for example. Safety is now automatic. The latest options include integrated, networked safety systems that use reliable safety PLC technology. Designed and built according to IEC guidelines and tested by nationally recognized testing laboratories, such as Technical Inspection Association (TUV) and Underwriters Laboratories (UL), PLCs, buses, I/Os, and other components are replacing traditional hardwiring on machines.
The most important benefit of integrated, automated machine safety is enhanced operator protection. According to one study, machine-related injuries are among the most common in the workplace. The National Institute for Occupational Safety and Health (NIOSH) indicates the fatality rate from machine-related accidents was second only to motor vehicle-related accidents and recorded higher fatality rates than from homicides, falls, and electrocutions. In addition to protecting machine operators, machine builders and end users alike are realizing other benefits to enhancing machine safety:
- Lower cost of controls
- Speed time to market
- Decrease machine downtime
- Reduce litigation
Incorporating safety into machine designs begins by understanding recent changes in international safety standards and regulations. Then, it is simply a matter of applying the appropriate safety options to meet these requirements. When considering these options, it is important to include total lifecycle costs in the decision-making process.
To read the full article on streamlining safety systems, click here.
About the Author
John D’Silva, safety technology manager at Siemens, is a professional engineer with 17 years industrial experience around the globe, including more than 10 years of functional safety in North America. OSHA & TUV certified, he also works in coordination with UL, NFPA, RIA, TUV, and other machine safety standards organizations to assist customers with their safety compliance and application requirements. Contact John at john.dsilva@siemens.com.
