A Programmable Logic Controller (PLC) is a specialized computing system widely used to control real-time industrial processes and assemblies. The block diagram of a generic PLC is shown in Figure 1.

In Part III of this series, we examined PLC programming methods (ladder logic and functional block diagram), and how the objects (coils and contacts) are system variables stored in the PLCs memory. We ...

This paper attempts a journey right from configuring a PLC, writing application program to code generation along with run-time configurations and RTOS abstraction for embedding it into PLC hardware ...

User-defined instructions (UDIs) let engineers write logic once and reuse it across many components, eliminating tedious copy-paste duplication. Any updates to a UDI definition automatically propagate ...

When a PLC is used primarily to replace relays, timers, and counters, it's hard to beat the simplicity and usefulness of ladder diagram programming. Their ability to accept programming in ladder ...

A human machine interface (HMI) connected to a separate programmable logic controller (PLC) is the standard system for machine automation. However, combining PLC processing and HMI monitoring and ...