Not every presumed “emergency” requires full shutdown of a machine system. Yet, traditional safety systems offered only complete removal of power regardless of the risk level involvedwww.cechina.cn, resulting in unavoidable loss of productivity.
　　A newer approach is based on comprehensive risk and reliability assessment of the machine system which is then associated with the degree of machine shutdown needed to prevent harm or injury. This allows safe access to machines with the main power left on, to ease setups and troubleshooting and more quickly return to production. Added safety functions prevent unwanted or accidental motion of motors and actuators.

Ever increasing speeds of machines and manufacturing processes underscore the need for enhanced onboard safety functions.

　　Safety standards have defined functional safety and made it a necessary part of motion control, whereas previously these were separate systems. Europe has led the way with standards like EN 954-1 and IEC 61508控制工程网版权所有, but the 2007 revision of NFPA 79 opened up functional safety to U.S. manufacturers and users. (See more on safety standards online.) Experts say the real driver for integrationwww.cechina.cn, however控制工程网版权所有, has been the ability to verify functional safety by tests according to the standards by a nationally recognized testing laboratory.
　　SafetyCONTROL ENGINEERING China版权所有, integrationwww.cechina.cn, benefits
　　Amid examining technology and productivity issues it’s important to remember the main concern of safe motion: prevention of worker injury or fatality.
　　Bosch Rexroth Corp. (BRC) considers immediate connectivity and quicker machine stopping time the prime benefit of integrating safety and motion. “When a safety function is activated, you don’t want additional delays 

　　Bosch Rexroth's drivebased SafeMotion and controller-based Safe Logic systems allow operators safe access to food processing or packaging machines to rectify a fault quickly without the need for shutdown.

　　with fieldbus couplers and/or a slow monitoring PLC to first determi