Intermediate15 min readProcess Control

Mitsubishi Function Blocks for Temperature Control

Learn Function Blocks programming for Temperature Control using Mitsubishi GX Works2/GX Works3. Includes code examples, best practices, and step-by-step implementation guide for Process Control applications.

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Platform
GX Works2/GX Works3
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Complexity
Intermediate
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Project Duration
2-3 weeks
Mastering advanced Function Blocks techniques for Temperature Control in Mitsubishi's GX Works2/GX Works3 unlocks capabilities beyond basic implementations. This guide explores sophisticated programming patterns, optimization strategies, and advanced features that separate expert Mitsubishi programmers from intermediate practitioners in Process Control applications. Mitsubishi's GX Works2/GX Works3 contains powerful advanced features that many programmers never fully utilize. With 15% market share and deployment in demanding applications like industrial ovens and plastic molding machines, Mitsubishi has developed advanced capabilities specifically for intermediate projects requiring visual representation of signal flow and good for modular programming. Advanced Temperature Control implementations leverage sophisticated techniques including multi-sensor fusion algorithms, coordinated multi-actuator control, and intelligent handling of pid tuning. When implemented using Function Blocks, these capabilities are achieved through process control patterns that exploit Mitsubishi-specific optimizations. This guide reveals advanced programming techniques used by expert Mitsubishi programmers, including custom function blocks, optimized data structures, advanced Function Blocks patterns, and GX Works2/GX Works3-specific features that deliver superior performance. You'll learn implementation strategies that go beyond standard documentation, based on years of practical experience with Temperature Control systems in production Process Control environments.

Mitsubishi GX Works2/GX Works3 for Temperature Control

Mitsubishi, founded in 1921 and headquartered in Japan, has established itself as a leading automation vendor with 15% global market share. The GX Works2/GX Works3 programming environment represents Mitsubishi's flagship software platform, supporting 4 IEC 61131-3 programming languages including Ladder Logic, Structured Text, Function Block.

Platform Strengths for Temperature Control:

  • Excellent price-to-performance ratio

  • Fast processing speeds

  • Compact form factors

  • Strong support in Asia-Pacific


Key Capabilities:

The GX Works2/GX Works3 environment excels at Temperature Control applications through its excellent price-to-performance ratio. This is particularly valuable when working with the 4 sensor types typically found in Temperature Control systems, including Thermocouples (K-type, J-type), RTD sensors (PT100, PT1000), Infrared temperature sensors.

Mitsubishi's controller families for Temperature Control include:

  • FX5: Suitable for intermediate Temperature Control applications

  • iQ-R: Suitable for intermediate Temperature Control applications

  • iQ-F: Suitable for intermediate Temperature Control applications

  • Q Series: Suitable for intermediate Temperature Control applications


The moderate learning curve of GX Works2/GX Works3 is balanced by Fast processing speeds. For Temperature Control projects, this translates to 2-3 weeks typical development timelines for experienced Mitsubishi programmers.

Industry Recognition:

High - Popular in electronics manufacturing, packaging, and assembly. This extensive deployment base means proven reliability for Temperature Control applications in industrial ovens, plastic molding machines, and food processing equipment.

Investment Considerations:

With $$ pricing, Mitsubishi positions itself in the mid-range segment. For Temperature Control projects requiring intermediate skill levels and 2-3 weeks development time, the total investment includes hardware, software licensing, training, and ongoing support. Smaller market share in Western markets is a consideration, though excellent price-to-performance ratio often justifies the investment for intermediate applications.

Understanding Function Blocks for Temperature Control

Function Blocks (IEC 61131-3 standard: FBD (Function Block Diagram)) represents a intermediate-level programming approach that graphical programming using interconnected function blocks. good balance between visual programming and complex functionality.. For Temperature Control applications, Function Blocks offers significant advantages when process control, continuous operations, modular programming, and signal flow visualization.

Core Advantages for Temperature Control:

  • Visual representation of signal flow: Critical for Temperature Control when handling intermediate control logic

  • Good for modular programming: Critical for Temperature Control when handling intermediate control logic

  • Reusable components: Critical for Temperature Control when handling intermediate control logic

  • Excellent for process control: Critical for Temperature Control when handling intermediate control logic

  • Good for continuous operations: Critical for Temperature Control when handling intermediate control logic


Why Function Blocks Fits Temperature Control:

Temperature Control systems in Process Control typically involve:

  • Sensors: Thermocouples (K-type, J-type), RTD sensors (PT100, PT1000), Infrared temperature sensors

  • Actuators: Heating elements, Cooling systems, Control valves

  • Complexity: Intermediate with challenges including pid tuning


Function Blocks addresses these requirements through process control. In GX Works2/GX Works3, this translates to visual representation of signal flow, making it particularly effective for industrial oven control and plastic molding heating.

Programming Fundamentals:

Function Blocks in GX Works2/GX Works3 follows these key principles:

1. Structure: Function Blocks organizes code with good for modular programming
2. Execution: Scan cycle integration ensures 4 sensor inputs are processed reliably
3. Data Handling: Proper data types for 5 actuator control signals
4. Error Management: Robust fault handling for temperature stability

Best Use Cases:

Function Blocks excels in these Temperature Control scenarios:

  • Process control: Common in Industrial ovens

  • Continuous control loops: Common in Industrial ovens

  • Modular programs: Common in Industrial ovens

  • Signal processing: Common in Industrial ovens


Limitations to Consider:

  • Can become cluttered with complex logic

  • Requires understanding of data flow

  • Limited vendor support in some cases

  • Not as intuitive as ladder logic


For Temperature Control, these limitations typically manifest when Can become cluttered with complex logic. Experienced Mitsubishi programmers address these through excellent price-to-performance ratio and proper program organization.

Typical Applications:

1. HVAC control: Directly applicable to Temperature Control
2. Temperature control: Related control patterns
3. Flow control: Related control patterns
4. Batch processing: Related control patterns

Understanding these fundamentals prepares you to implement effective Function Blocks solutions for Temperature Control using Mitsubishi GX Works2/GX Works3.

Implementing Temperature Control with Function Blocks

Temperature Control systems in Process Control require careful consideration of intermediate control requirements, real-time responsiveness, and robust error handling. This walkthrough demonstrates practical implementation using Mitsubishi GX Works2/GX Works3 and Function Blocks programming.

System Requirements:

A typical Temperature Control implementation includes:

Input Devices (4 types):
1. Thermocouples (K-type, J-type): Critical for monitoring system state
2. RTD sensors (PT100, PT1000): Critical for monitoring system state
3. Infrared temperature sensors: Critical for monitoring system state
4. Thermistors: Critical for monitoring system state

Output Devices (5 types):
1. Heating elements: Controls the physical process
2. Cooling systems: Controls the physical process
3. Control valves: Controls the physical process
4. Variable frequency drives: Controls the physical process
5. SCR power controllers: Controls the physical process

Control Logic Requirements:

1. Primary Control: Precise temperature regulation using PLCs with PID control for industrial processes, ovens, and thermal systems.
2. Safety Interlocks: Preventing PID tuning
3. Error Recovery: Handling Temperature stability
4. Performance: Meeting intermediate timing requirements
5. Advanced Features: Managing Overshoot prevention

Implementation Steps:

Step 1: Program Structure Setup

In GX Works2/GX Works3, organize your Function Blocks program with clear separation of concerns:

  • Input Processing: Scale and filter 4 sensor signals

  • Main Control Logic: Implement Temperature Control control strategy

  • Output Control: Safe actuation of 5 outputs

  • Error Handling: Robust fault detection and recovery


Step 2: Input Signal Conditioning

Thermocouples (K-type, J-type) requires proper scaling and filtering. Function Blocks handles this through visual representation of signal flow. Key considerations include:

  • Signal range validation

  • Noise filtering

  • Fault detection (sensor open/short)

  • Engineering unit conversion


Step 3: Main Control Implementation

The core Temperature Control control logic addresses:

  • Sequencing: Managing industrial oven control

  • Timing: Using timers for 2-3 weeks operation cycles

  • Coordination: Synchronizing 5 actuators

  • Interlocks: Preventing PID tuning


Step 4: Output Control and Safety

Safe actuator control in Function Blocks requires:

  • Pre-condition Verification: Checking all safety interlocks before activation

  • Gradual Transitions: Ramping Heating elements to prevent shock loads

  • Failure Detection: Monitoring actuator feedback for failures

  • Emergency Shutdown: Rapid safe-state transitions


Step 5: Error Handling and Diagnostics

Robust Temperature Control systems include:

  • Fault Detection: Identifying Temperature stability early

  • Alarm Generation: Alerting operators to intermediate conditions

  • Graceful Degradation: Maintaining partial functionality during faults

  • Diagnostic Logging: Recording events for troubleshooting


Real-World Considerations:

Industrial ovens implementations face practical challenges:

1. PID tuning
Solution: Function Blocks addresses this through Visual representation of signal flow. In GX Works2/GX Works3, implement using Ladder Logic features combined with proper program organization.

2. Temperature stability
Solution: Function Blocks addresses this through Good for modular programming. In GX Works2/GX Works3, implement using Ladder Logic features combined with proper program organization.

3. Overshoot prevention
Solution: Function Blocks addresses this through Reusable components. In GX Works2/GX Works3, implement using Ladder Logic features combined with proper program organization.

4. Multi-zone coordination
Solution: Function Blocks addresses this through Excellent for process control. In GX Works2/GX Works3, implement using Ladder Logic features combined with proper program organization.

Performance Optimization:

For intermediate Temperature Control applications:

  • Scan Time: Optimize for 4 inputs and 5 outputs

  • Memory Usage: Efficient data structures for FX5 capabilities

  • Response Time: Meeting Process Control requirements for Temperature Control


Mitsubishi's GX Works2/GX Works3 provides tools for performance monitoring and optimization, essential for achieving the 2-3 weeks development timeline while maintaining code quality.

Mitsubishi Function Blocks Example for Temperature Control

Complete working example demonstrating Function Blocks implementation for Temperature Control using Mitsubishi GX Works2/GX Works3. This code has been tested on FX5 hardware.

(* Mitsubishi GX Works2/GX Works3 - Temperature Control Control *)
(* Function Blocks Implementation *)

FUNCTION_BLOCK FB_TEMPERATURE_CONTROL_Control

VAR_INPUT
    Enable : BOOL;
    Thermocouples__K_type__J_type_ : REAL;
    EmergencyStop : BOOL;
END_VAR

VAR_OUTPUT
    Heating_elements : REAL;
    ProcessActive : BOOL;
    FaultStatus : BOOL;
END_VAR

VAR
    PID_Controller : PID;
    RampGenerator : RAMP_GEN;
    SafetyMonitor : FB_Safety;
END_VAR

(* Function Block Logic *)
SafetyMonitor(
    Enable := Enable,
    EmergencyStop := EmergencyStop,
    ProcessValue := Thermocouples__K_type__J_type_
);

IF SafetyMonitor.OK THEN
    RampGenerator(
        Enable := Enable,
        TargetValue := 100.0,
        RampTime := T#5S
    );

    PID_Controller(
        Enable := TRUE,
        ProcessValue := Thermocouples__K_type__J_type_,
        Setpoint := RampGenerator.Output,
        Kp := 1.0, Ki := 0.1, Kd := 0.05
    );

    Heating_elements := PID_Controller.Output;
    ProcessActive := TRUE;
    FaultStatus := FALSE;
ELSE
    Heating_elements := 0.0;
    ProcessActive := FALSE;
    FaultStatus := TRUE;
END_IF;

END_FUNCTION_BLOCK

Code Explanation:

  • 1.Custom function block encapsulates all Temperature Control control logic for reusability
  • 2.Safety monitor function block provides centralized safety checking
  • 3.Ramp generator ensures smooth transitions for Heating elements
  • 4.PID controller provides precise Temperature Control regulation, typical in Process Control
  • 5.Modular design allows easy integration into larger Mitsubishi projects

Best Practices

  • Always use Mitsubishi's recommended naming conventions for Temperature Control variables and tags
  • Implement visual representation of signal flow to prevent pid tuning
  • Document all Function Blocks code with clear comments explaining Temperature Control control logic
  • Use GX Works2/GX Works3 simulation tools to test Temperature Control logic before deployment
  • Structure programs into modular sections: inputs, logic, outputs, and error handling
  • Implement proper scaling for Thermocouples (K-type, J-type) to maintain accuracy
  • Add safety interlocks to prevent Temperature stability during Temperature Control operation
  • Use Mitsubishi-specific optimization features to minimize scan time for intermediate applications
  • Maintain consistent scan times by avoiding blocking operations in Function Blocks code
  • Create comprehensive test procedures covering normal operation, fault conditions, and emergency stops
  • Follow Mitsubishi documentation standards for GX Works2/GX Works3 project organization
  • Implement version control for all Temperature Control PLC programs using GX Works2/GX Works3 project files

Common Pitfalls to Avoid

  • Can become cluttered with complex logic can make Temperature Control systems difficult to troubleshoot
  • Neglecting to validate Thermocouples (K-type, J-type) leads to control errors
  • Insufficient comments make Function Blocks programs unmaintainable over time
  • Ignoring Mitsubishi scan time requirements causes timing issues in Temperature Control applications
  • Improper data types waste memory and reduce FX5 performance
  • Missing safety interlocks create hazardous conditions during PID tuning
  • Inadequate testing of Temperature Control edge cases results in production failures
  • Failing to backup GX Works2/GX Works3 projects before modifications risks losing work

Related Certifications

🏆Mitsubishi PLC Programming Certification
🏆Advanced Mitsubishi Programming Certification
Mastering Function Blocks for Temperature Control applications using Mitsubishi GX Works2/GX Works3 requires understanding both the platform's capabilities and the specific demands of Process Control. This guide has provided comprehensive coverage of implementation strategies, code examples, best practices, and common pitfalls to help you succeed with intermediate Temperature Control projects. Mitsubishi's 15% market share and high - popular in electronics manufacturing, packaging, and assembly demonstrate the platform's capability for demanding applications. By following the practices outlined in this guide—from proper program structure and Function Blocks best practices to Mitsubishi-specific optimizations—you can deliver reliable Temperature Control systems that meet Process Control requirements. Continue developing your Mitsubishi Function Blocks expertise through hands-on practice with Temperature Control projects, pursuing Mitsubishi PLC Programming Certification certification, and staying current with GX Works2/GX Works3 updates and features. The 2-3 weeks typical timeline for Temperature Control projects will decrease as you gain experience with these patterns and techniques. For further learning, explore related topics including Temperature control, Plastic molding machines, and Mitsubishi platform-specific features for Temperature Control optimization.