Safeguarding Against Machine Hazards

Modules and Controllers

Another family of devices that fall under the heading of complementary protective equipment is safety modules, safety controllers and safety PLCs. Safety modules interface safety-related devices, such as the safety solutions described above, directly to the machine control, providing an increased level of safety functionality with self-checking logic. They can identify faults within a safety-related device or circuit, as well as monitor their own circuitry and outputs, simplifying the task of machine design, while also increasing the level of safety. Safety modules tend to monitor one or two safety or safeguarding devices.

For incorporating numerous input devices and managing multiple safety-related functions, a configurable safety controller can be used. Generally, easy-to-configure safety controllers can replace multiple dedicated safety modules to integrate E-stop buttons, interlocking switches, safety light screens, two-hand controls and many other devices, providing a cost-effective safety solution that protects against costly damage to machines as well as injuries to personnel.

Machine safety is everyone's responsibility, from the machine designer, to the installer and integrator, to the operator and maintenance personnel and, ultimately, the employer. There are a number of solutions for every problem and many resources to help achieve the goal of a safe working environment. Rely on trusted sources, such as OSHA, the ANSI standards that cover your particular situation and the many well known suppliers of safety and safeguarding equipment.

Mike Carlson has been employed in the machine safeguarding field for 20 years. He has worked with Minneapolis-based Banner Engineering for the past 12 years, where he develops and promotes safety products and the education of safeguarding solutions, safety product literature, sales brochures and Web-based information. Carlson is involved in the development of several safety standards recognized by ANSI.

This article originally appeared in MHM's sister publication, EHS Today.