Modeling Multicore Programmable Logic Controllers in Networked Automation Systems

Integrating Multicore Programmable Logic Controllers (PLC) in Networked Automation Systems (NAS) promises a higher computing performance and PLC manufactures are launching their first Multicore PLCs (MPLC). However, analyzing the MPLCs time behavior considering distributing automation tasks on different cores is more complex than analyzing the time behavior of single-core PLCs. For increasing analyzability of NAS a modeling notation is needed. However, MPLCs are not considered sufficiently in modeling NAS nowadays. In this paper, properties and requirements of MPLCs regarding the distribution of automation tasks on multiple cores are explored. These properties and requirements affect real-time constraints of automation tasks of a Multicore-Capable NAS (MCNAS). Based on the explored properties and requirements a modeling notation for modeling MPLCs is proposed. This modeling notation offers the automation engineer higher analyzability of the time behavior of MCNAS.