ProfiSafe safety layer on top of Profinet and Profibus

Safety network: PI North America, the organization for Profinet and Profibus, explains use of the ProfiSafe safety network on top of industrial Ethernet, Profinet, and device-level Profibus networks.
By CFE Media July 4, 2017

Figure 1: Controllers, networking equipment, and operator interface software are the three most specified or used technologies with use, connect with, or support mobility, Ethernet, or wireless technologies. Safety devices were used by 31% of respondentsNetworked safety for PI North America involves using ProfiSafe, an additional software layer used on top of Profinet (industrial Ethernet) and Profibus (device-level) networks. According to the organization, ProfiSafe:

  • Adds functional safety to an existing automation network, running on the same cables.
  • Compared to wired circuits, requires less engineering, less cable, faster commissioning, and easier maintenance.
  • Has been available since 2001 with nearly 7 million ProfiSafe devices in operation in 2016.
  • Can be used with wireless (such as WLAN and Bluetooth) and with open Ethernet backbones.
  • Works by reducing error probabilities in transmitted data between certified devices and controllers and includes safety checks.
  • Operates without interference, avoiding impact on connected standard bus protocols and automation systems.
  • Can be used for safety applications up to SIL3 according to IEC 61508/IEC 62061, or Category 4 according to EN 954-1, or PL "e" according to ISO 13849-1.

To implement ProfiSafe, one must first assess risks, determine a mitigation strategy (including controls, guarding, signage, etc.), use a ProfiSafe controller and input and output (IO) devices, and finally, reassess periodically. ProfiSafe also can integrate AS-i Safety at Work, said Michael Bowne, PI North America, executive director, citing ProfiSafe training materials.

Of the industrial Ethernet protocols, Profinet ranked third, in the 2016 Mobility, Ethernet, Wireless Report from Control Engineering. Courtesy: 2016 Mobility, Ethernet, Wireless Report 

– Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering, mhoske@cfemedia.com.

MORE ADVICE

Key concepts

  • A safety network has been available to use with Profinet and Profibus.
  • ProfiSafe safety network is more flexible and less costly than hardwired safety.
  • Use of ProfiSafe has been carefully documented and help is available from the PI North America organization.

Consider this

If you’re hardwiring safety, have you considered savings available by implementing a safety network?

ONLINE extra

Below, link to the application story about how ProfiSafe was used with the Boeing 787 Dreamliner, as integrated by Advanced Integration Technology (AIT). 

Link to more info from PI North America