SIGNAL+DRAHT | Issue 09/2022
The independent safety assessment and certification of PLC for railway applications
Programmable logic controllers (PLC) are increasingly being used in railway applications. Typically, these PLC have already been certified by an independent safety assessor (ISA) as a “generic product” for industrial applications according to IEC 61508 [8] and require a further additional ISA assessment with optional certification according to EN 50126-1/-2 [9], EN 50128 / EN 50657 [10, 11] and EN 50129 [12] for railway applications. The use of a PLC that has already been certified as a “generic product” according to IEC 61508 [8] has the advantage that an existing and proven industrial product can be used instead of developing a PLC that uses a complex and expensive approach....