Pn4PLC: Verification of Software Upgrade for PLC Code

Most automation engineering tools and platforms are old and are considered legacy software. However, vendors want to upgrade the hardware and relevant software of existing tools and platforms to meet end-user requirements. These changes can potentially introduce code errors, posing a safety risk. Detecting the introduction of such defects in line with strict industry safety requirements is crucial. Behavioural verification using equivalence checking is one of the techniques that can be used to detect software bugs. In this paper, we present a novel Petri net-based behavioral equivalence checking method to detect errors during software upgrades.