Programming vs Configuration in a Programmable Logic Controller (PLC) System
Understanding the differences between programming and configuration in a Programmable Logic Controller (PLC) system is crucial for system integrators, engineers, and anyone involved in industrial automation. This article aims to clarify these concepts, providing a clear distinction between the two processes and explaining how they are applied in the context of PLC systems.
Introduction to Programming and Configuration
Programming and configuration are fundamental aspects of any system that involves automation, such as a Programmable Logic Controller (PLC) system. While both processes contribute to the functionality of the system, they serve different purposes and require distinct skills and methodologies.
Programming of a PLC System
Programming in a PLC system involves defining the logic and steps required to achieve specific goals. This process is similar to programming other systems, such as Windows embedded systems or any other OSes. The primary focus of programming a PLC is to write the control algorithms and logic that determine how the system will function to meet the desired specifications.
Logic Definition: Programming in a PLC entails creating a set of instructions that dictate the sequence of operations. These instructions can be written in various programming languages, with C being a common choice for most devices. However, some PLCs may require the use of Ladder Logic, which is a graphical programming language specific to PLC systems.Algorithm Development: The programmer must develop algorithms that control the behavior of the system based on specific inputs and outputs. This includes handling various scenarios and ensuring that the system operates efficiently and accurately.Flexibility: Modern PLC systems often come with the flexibility to use different programming languages, allowing for a wide range of control strategies and programming approaches.Configuration of a PLC System
Configuration, on the other hand, involves setting up the physical and logical properties of the PLC system. This process ensures that the hardware and software are properly integrated and ready for programming. Configuration is crucial for the proper operation of any PLC system and forms the foundation for the programming phase.
Setpoint Setup: Configuration involves defining the setpoints for the PLC’s inputs, outputs, and sensing capabilities. These parameters determine how the system will interact with the physical environment and provide the necessary feedback for control.Networking Setup: Configuration also includes setting up the networking systems and serial port configurations. This ensures that the PLC can communicate with other devices and systems, facilitating data exchange and control.Hardware I/O Setup: The hardware interface (Human Interface Device - HMI) and Input/Output (I/O) connections are configured to ensure that the PLC can interact with the real-world processes it controls. This includes setting up the physical connections and defining the signal types (e.g., digital, analog).Key Differences
The main differences between programming and configuration in a PLC system can be summarized as follows:
Focus: Programming focuses on the logical implementation of control algorithms, while configuration focuses on the physical setup and integration of the system.Scope: Programming is concerned with the behavior of the system, whereas configuration is about establishing the correct connection between the hardware and software.Flexibility: Programming can often be done using different languages, while configuration is more specific to the hardware and its physical connections.Conclusion
Understanding the difference between programming and configuration in a PLC system is vital for ensuring the proper operation and efficiency of the automation process. Effective programming requires a thorough understanding of control logic and the chosen programming language, while configuration demands knowledge of the hardware setup and communication protocols.
Further Reading
For more detailed information on PLC systems, programming, and configuration, the following resources may be helpful:
Plc-Systems: Programming vs. Configuration in PLC SystemsControl Engineering: Human Machine Interfaces - Configuration Settings ExplainedInstitute FCPLC: Introduction to Ladder Logic Programming for PLCs