Machinery and original equipment manufacturer (OEM) designers know that building safety into their equipment is a fundamental requirement. To ensure a consistent approach, the ISO 13849 standard provides guidance for machinery control systems that are applied to provide safety functions for machinery. However, safety design is a complicated subject, and it can be difficult to interpret by both OEMs and their end user customers.
The ISO standard identifies many categories of safety depending on the performance level. There can be a tendency for designers to follow the most restrictive category definitions, often being overly conservative, but any engineer knows that an over-specified design isn’t always prudent. This is especially the case when designers are faced with accommodating the high costs usually associated with more elaborate schemes.