DGUV Test position paper on the safety of control systems on machinery

Control system architectures are assigned to five categories that can achieve one of five Performance Levels (PL). In accordance with the current version of the standard, single-channel electronic control systems without testing and redundancy only achieve the lowest category (category B), and a maximum PL b. If only well-tried components are used, the higher category 1 and PL c can be achieved, which enables use in applications where a higher risk is present.

But what components are considered to be well-tried? According to the standard, so far only mechanical components are included. There are also demands however to include electronic components such as microchips, microprocessors or programmable logic controllers (PLCs) in the list of well-tried components. The position paper explains why, in the view of DGUV Test, the current exclusion of complex electronic components from the list of well-tried components remains correct.

DGUV Test Information 06: Can PL c be achieved with a standards PLC?