Certification of Safe fieldbus communication with SafetyBUS p®

Notified bodies such as TÜV and BG have approved safe communication via SafetyBUS p for use in safety-related applications in accordance with the following standards:

• SIL 3 in accordance with IEC 61508
• Category 4 in accordance with EN 954-1
• PL e in accordance with ISO 13849
• SIL 3 in accordance with IEC 62061

Diagnostics
Diagnostic information from the subscriber is made available to the Management Device, which is usually a safety control system. The safety control system can provide this information to common standard communication systems such as Profi bus DP, CANopen or Ethernet/IP, for example.

Communication media
A wide range of communication media is available to SafetyBUS p, enabling it to satisfy the varied application requirements. Communication may therefore be copper, wireless, light or fiber-optic based.

Fiber-optic communication
With fiber-optic (FO) communication, fiber-optic cables, transmitters and receivers are used instead of copper cables. Fibre-optic routers are used on SafetyBUS p for this purpose. For safety control systems with SafetyBUS p interface, the fiber-optic routers are totally transparent, i. e. copper-based communication can simply be swapped for fiber-optic communication, without having to reconfigure the control system. SafetyBUS p has a number of different devices for creating fiber-optic paths. Fiber-optic converters can be selected for glass fiber paths from 4 to 40 kilometres, depending on the application. Integrated routing functions enable network segmentation. As a result, different transmission rates are possible within the segments connected via FO. The FO router also filters messages in SafetyBUS p, so that they only reach the segments for which they are intended. This reduces the network load in the remote bus segment.

Today, FO communication is found in a wide range of applications. It's important where a high EMC load would disrupt communication, as would be the case with welding robots in the automotive industry, for example. Fiber-optic paths are also used for safety-related communication between the mountain and valley stations on cablecars, where it's necessary to span long distances outdoors. This technology is also used to reduce reaction times in safety technology. On copper-based networks, the data transmission rate depends on the cable runs, so the reaction time of the safety technology increases with the length of the bus cable. This dependency is lower on FO-based networks, so a short reaction time is guaranteed, even over long  distances.