MELSEC System Q Programmable Logic Controllers Beginners Manual


MELSEC System Q Programmable Logic Controllers

Beginner’s Manual

Introduction to MELSEC System Q

The MELSEC System Q is a high-performance Programmable Logic Controller (PLC) developed by Mitsubishi Electric. It is designed to meet the demands of modern industrial automation with its modular design, powerful processors, and extensive connectivity options. This beginner’s manual provides a step-by-step guide for understanding, programming, and operating the MELSEC System Q, making it easier for newcomers to get started.

Chapter 1: Overview of MELSEC System Q

1.1 Key Features

  • Modular Design: Flexible configuration for various application sizes.
  • High-Speed Processing: Handles complex tasks with precision and speed.
  • Scalable System: Easily expand the system with additional modules for I/O, communication, or special functions.
  • Network Integration: Supports multiple protocols like Ethernet, CC-Link, and Modbus.
  • User-Friendly Programming: Compatible with GX Works2/GX Developer software for intuitive programming.

1.2 Applications

  • Factory automation.
  • Machine control.
  • Building automation systems.
  • Process control in industries like food, pharmaceutical, and automotive.

Chapter 2: Hardware Components

2.1 Main Components

  1. CPU Module: The core of the system, responsible for processing logic and managing communication.
  2. Power Supply Module: Provides the necessary power to the system.
  3. Base Unit: Houses the CPU and other modules, with slots for easy installation.
  4. I/O Modules: Connect to sensors and actuators for controlling industrial devices.
  5. Special Function Modules: For advanced tasks such as motion control, data logging, or communication.

2.2 System Configuration

A basic MELSEC System Q configuration includes:

  • One power supply module.
  • One CPU module.
  • I/O modules as required for the application.

Chapter 3: Installation and Setup

3.1 Installing the System

  1. Mounting: Install the base unit securely on a DIN rail or control panel.
  2. Module Placement: Insert the power supply and CPU module into designated slots. Add I/O and special function modules as needed.
  3. Wiring:
    • Connect inputs such as switches or sensors to the input modules.
    • Connect outputs like relays or motors to the output modules.
    • Ensure proper grounding to prevent electrical interference.

3.2 Powering On

  • Check all connections and ensure correct module placement.
  • Switch on the power supply and verify that the system LEDs indicate normal operation.

Chapter 4: Programming Basics

4.1 Programming Tools

MELSEC System Q is programmed using:

  • GX Works2: Advanced programming software with graphical and text-based options.
  • GX Developer: Traditional programming tool for ladder logic and other IEC 61131-3 languages.

4.2 Programming Languages

  1. Ladder Diagram (LD): Visual programming for ease of understanding.
  2. Instruction List (IL): Text-based programming for compact and efficient code.
  3. Structured Text (ST): High-level language for complex tasks.
  4. Function Block Diagram (FBD): Graphical programming using predefined function blocks.

4.3 Basic Programming Concepts

  • Inputs (X): Physical devices like buttons or sensors.
  • Outputs (Y): Devices controlled by the PLC, such as lights or motors.
  • Internal Relays (M): Virtual relays for internal logic control.
  • Timers (T) and Counters (C): Used for time-based and count-based operations.

Chapter 5: Communication and Networking

5.1 Built-In Communication Options

  • Ethernet: For high-speed networking and remote access.
  • RS-232/RS-485: For serial communication with external devices.

5.2 Network Protocols

  • CC-Link: High-speed industrial communication for real-time control.
  • Modbus: Protocol for device-to-device communication.
  • PROFINET: Integration with Siemens devices and systems.

5.3 Data Sharing

MELSEC System Q allows seamless data exchange with HMIs (Human-Machine Interfaces), SCADA (Supervisory Control and Data Acquisition) systems, and MES (Manufacturing Execution Systems).

Chapter 6: Hands-On Exercises

Exercise 1: Basic On/Off Control

Objective: Turn on an output (e.g., a light) when an input (e.g., a switch) is activated.

Ladder Logic Example:

  • Input X0: Switch.
  • Output Y0: Light.
| X2 |---| |---[ C1 K10 ]  
[C1 ]---| |---( Y2 )  

Chapter 7: Maintenance and Troubleshooting
7.1 Preventive Maintenance
  1. Inspect all connections periodically.
  2. Ensure firmware and software are up to date.
  3. Clean the PLC and surroundings to prevent dust accumulation.
7.2 Troubleshooting Common Issues
  1. Power Issues: Check the power supply and wiring.
  2. I/O Malfunctions: Verify connections and test the devices.
  3. Program Errors: Debug logic using GX Works2 or GX Developer.
7.3 Diagnostics Tools
  • System LEDs: Indicate the status of power, run mode, and errors.
  • Error Logs: Access detailed error information using the programming software.
Chapter 8: Advanced Features
8.1 Data Logging
  • Use special function modules to log process data for analysis and reporting.
8.2 Analog Control
  • Connect analog input/output modules for precise control of variables like temperature and pressure.
8.3 PID Control
  • Implement PID loops for advanced control applications, such as regulating speed or maintaining temperature.
Conclusion
The MELSEC System Q is a versatile and powerful PLC system designed for modern industrial automation. By understanding its hardware, programming capabilities, and communication features, you can build efficient and reliable control systems. This beginner’s manual provides the foundational knowledge to start working with MELSEC System Q PLCs confidently.
Appendices
  • Appendix A: Specifications of MELSEC System Q Modules.
  • Appendix B: List of Common Instructions.
  • Appendix C: Example Ladder Logic Diagrams for Reference.
For further assistance, refer to Mitsubishi Electric’s official documentation or contact their support team.

You have to wait 10 seconds.

Download Timer
Tags:
Previous Post Next Post