Intermediate15 min readProcess Control

ABB Function Blocks for Temperature Control

Learn Function Blocks programming for Temperature Control using ABB Automation Builder. Includes code examples, best practices, and step-by-step implementation guide for Process Control applications.

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Platform
Automation Builder
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Complexity
Intermediate
⏱️
Project Duration
2-3 weeks
Learning to implement Function Blocks for Temperature Control using ABB's Automation Builder is an essential skill for PLC programmers working in Process Control. This comprehensive guide walks you through the fundamentals, providing clear explanations and practical examples that you can apply immediately to real-world projects. ABB has established itself as Medium - Strong in power generation, mining, and marine applications, making it a strategic choice for Temperature Control applications. With 8% global market share and 3 popular PLC families including the AC500 and AC500-eCo, ABB provides the robust platform needed for intermediate complexity projects like Temperature Control. The Function Blocks approach is particularly well-suited for Temperature Control because process control, continuous operations, modular programming, and signal flow visualization. This combination allows you to leverage visual representation of signal flow while managing the typical challenges of Temperature Control, including pid tuning and temperature stability. Throughout this guide, you'll discover step-by-step implementation strategies, working code examples tested on Automation Builder, and industry best practices specific to Process Control. Whether you're programming your first Temperature Control system or transitioning from another PLC platform, this guide provides the practical knowledge you need to succeed with ABB Function Blocks programming.

ABB Automation Builder for Temperature Control

Automation Builder provides ABB's unified environment for AC500 PLC programming, drive configuration, and HMI development. Built on CODESYS V3 with ABB-specific enhancements. Strength lies in seamless drive integration with ACS880 and other families....

Platform Strengths for Temperature Control:

  • Excellent for robotics integration

  • Strong in power and utilities

  • Robust hardware for harsh environments

  • Good scalability


Unique ${brand.software} Features:

  • Integrated drive configuration for ACS880, ACS580 drives

  • Extensive application libraries: HVAC, pumping, conveying, crane control

  • Safety programming for AC500-S within standard project

  • Panel Builder 600 HMI development integrated


Key Capabilities:

The Automation Builder environment excels at Temperature Control applications through its excellent for robotics integration. 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.

Control Equipment for Temperature Control:

  • Electric resistance heaters (cartridge, band, strip)

  • Steam injection systems

  • Thermal fluid (hot oil) systems

  • Refrigeration and chiller systems


ABB's controller families for Temperature Control include:

  • AC500: Suitable for intermediate Temperature Control applications

  • AC500-eCo: Suitable for intermediate Temperature Control applications

  • AC500-S: Suitable for intermediate Temperature Control applications

Hardware Selection Guidance:

PM554 entry-level for simple applications. PM564 mid-range for OEM machines. PM573 high-performance for complex algorithms. PM5 series latest generation with cloud connectivity. AC500-S for integrated safety....

Industry Recognition:

Medium - Strong in power generation, mining, and marine applications. AC500 coordinating VFD-controlled motors with ACS880 drives. Energy optimization reducing consumption 25-40%. Robot integration via ABB robot interfaces. Press line automation with AC500-S safety....

Investment Considerations:

With $$ pricing, ABB 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.

Understanding Function Blocks for Temperature Control

Function Block Diagram (FBD) is a graphical programming language where functions and function blocks are represented as boxes connected by signal lines. Data flows from left to right through the network.

Execution Model:

Blocks execute based on data dependencies - a block executes only when all its inputs are available. Networks execute top to bottom when dependencies allow.

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: RTDs (PT100/PT1000) for high-accuracy measurements, Thermocouples (J, K, T types) for high-temperature applications, Infrared pyrometers for non-contact measurement

  • Actuators: SCR (thyristor) power controllers for electric heaters, Solid-state relays for on/off heating control, Proportional control valves for steam or thermal fluid

  • Complexity: Intermediate with challenges including Long thermal time constants making tuning difficult


Control Strategies for Temperature Control:

  • pid: Standard PID control with proportional, integral, and derivative terms tuned for the thermal process dynamics

  • cascade: Master temperature loop outputs to slave heater/cooler control loop for tighter control

  • ratio: Maintain temperature ratio between zones for gradient applications


Programming Fundamentals in Function Blocks:

StandardBlocks:
- logic: AND, OR, XOR, NOT - Boolean logic operations
- comparison: EQ, NE, LT, GT, LE, GE - Compare values
- math: ADD, SUB, MUL, DIV, MOD - Arithmetic operations

TimersCounters:
- ton: Timer On-Delay - Output turns ON after preset time
- tof: Timer Off-Delay - Output turns OFF after preset time
- tp: Pulse Timer - Output pulses for preset time

Connections:
- wires: Connect output pins to input pins to pass data
- branches: One output can connect to multiple inputs
- feedback: Outputs can feed back to inputs for state machines

Best Practices for Function Blocks:

  • Arrange blocks for clear left-to-right data flow

  • Use consistent spacing and alignment for readability

  • Label all inputs and outputs with meaningful names

  • Create custom FBs for frequently repeated logic patterns

  • Minimize wire crossings by careful block placement


Common Mistakes to Avoid:

  • Creating feedback loops without proper initialization

  • Connecting incompatible data types

  • Not considering execution order dependencies

  • Overcrowding networks making them hard to read


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 ABB Automation Builder.

Implementing Temperature Control with Function Blocks

Industrial temperature control systems use PLCs to regulate process temperatures in manufacturing, food processing, chemical processing, and other applications. These systems maintain precise temperature setpoints through heating and cooling control while ensuring product quality and energy efficiency.

This walkthrough demonstrates practical implementation using ABB Automation Builder and Function Blocks programming.

System Requirements:

A typical Temperature Control implementation includes:

Input Devices (Sensors):
1. RTDs (PT100/PT1000) for high-accuracy measurements: Critical for monitoring system state
2. Thermocouples (J, K, T types) for high-temperature applications: Critical for monitoring system state
3. Infrared pyrometers for non-contact measurement: Critical for monitoring system state
4. Thermistors for fast response applications: Critical for monitoring system state
5. Thermal imaging cameras for surface temperature monitoring: Critical for monitoring system state

Output Devices (Actuators):
1. SCR (thyristor) power controllers for electric heaters: Primary control output
2. Solid-state relays for on/off heating control: Supporting control function
3. Proportional control valves for steam or thermal fluid: Supporting control function
4. Solenoid valves for cooling water or refrigerant: Supporting control function
5. Variable frequency drives for cooling fan control: Supporting control function

Control Equipment:

  • Electric resistance heaters (cartridge, band, strip)

  • Steam injection systems

  • Thermal fluid (hot oil) systems

  • Refrigeration and chiller systems


Control Strategies for Temperature Control:

  • pid: Standard PID control with proportional, integral, and derivative terms tuned for the thermal process dynamics

  • cascade: Master temperature loop outputs to slave heater/cooler control loop for tighter control

  • ratio: Maintain temperature ratio between zones for gradient applications


Implementation Steps:

Step 1: Characterize thermal system dynamics (time constants, dead time)

In Automation Builder, characterize thermal system dynamics (time constants, dead time).

Step 2: Select appropriate sensor type and placement for representative measurement

In Automation Builder, select appropriate sensor type and placement for representative measurement.

Step 3: Size heating and cooling capacity for worst-case load conditions

In Automation Builder, size heating and cooling capacity for worst-case load conditions.

Step 4: Implement PID control with appropriate sample time (typically 10x faster than process time constant)

In Automation Builder, implement pid control with appropriate sample time (typically 10x faster than process time constant).

Step 5: Add output limiting and anti-windup for safe operation

In Automation Builder, add output limiting and anti-windup for safe operation.

Step 6: Program ramp/soak profiles if required

In Automation Builder, program ramp/soak profiles if required.


ABB Function Design:

Standard FB structure with VAR_INPUT/OUTPUT/VAR. Methods extend functionality. ABB application libraries provide tested FBs. Drive FBs wrap drive parameter access.

Common Challenges and Solutions:

1. Long thermal time constants making tuning difficult

  • Solution: Function Blocks addresses this through Visual representation of signal flow.


2. Transport delay (dead time) causing instability

  • Solution: Function Blocks addresses this through Good for modular programming.


3. Non-linear response at different temperature ranges

  • Solution: Function Blocks addresses this through Reusable components.


4. Sensor placement affecting measurement accuracy

  • Solution: Function Blocks addresses this through Excellent for process control.


Safety Considerations:

  • Independent high-limit safety thermostats (redundant to PLC)

  • Watchdog timers for heater control validity

  • Safe-state definition on controller failure (heaters off)

  • Thermal fuse backup for runaway conditions

  • Proper ventilation for combustible atmospheres


Performance Metrics:

  • Scan Time: Optimize for 4 inputs and 5 outputs

  • Memory Usage: Efficient data structures for AC500 capabilities

  • Response Time: Meeting Process Control requirements for Temperature Control

ABB Diagnostic Tools:

Online monitoring with live values,Watch window with expressions,Breakpoints for inspection,Drive diagnostics showing fault history,Communication diagnostics for network statistics

ABB's Automation Builder provides tools for performance monitoring and optimization, essential for achieving the 2-3 weeks development timeline while maintaining code quality.

ABB Function Blocks Example for Temperature Control

Complete working example demonstrating Function Blocks implementation for Temperature Control using ABB Automation Builder. Follows ABB naming conventions. Tested on AC500 hardware.

(* ABB Automation Builder - Temperature Control Control *)
(* Reusable Function Blocks Implementation *)
(* Standard FB structure with VAR_INPUT/OUTPUT/VAR. Methods ext *)

FUNCTION_BLOCK FB_TEMPERATURE_CONTROL_Controller

VAR_INPUT
    bEnable : BOOL;                  (* Enable control *)
    bReset : BOOL;                   (* Fault reset *)
    rProcessValue : REAL;            (* RTDs (PT100/PT1000) for high-accuracy measurements *)
    rSetpoint : REAL := 100.0;  (* Target value *)
    bEmergencyStop : BOOL;           (* Safety input *)
END_VAR

VAR_OUTPUT
    rControlOutput : REAL;           (* SCR (thyristor) power controllers for electric heaters *)
    bRunning : BOOL;                 (* Process active *)
    bComplete : BOOL;                (* Cycle complete *)
    bFault : BOOL;                   (* Fault status *)
    nFaultCode : INT;                (* Diagnostic code *)
END_VAR

VAR
    (* Internal Function Blocks *)
    fbSafety : FB_SafetyMonitor;     (* Safety logic *)
    fbRamp : FB_RampGenerator;       (* Soft start/stop *)
    fbPID : FB_PIDController;        (* Process control *)
    fbDiag : FB_Diagnostics;         (* ST_Alarm structure with bActive, bAcknowledged, dtActivation, nCode, sMessage. Array of alarms with detection and acknowledgment logic. Integration with ABB alarm libraries. *)

    (* Internal State *)
    eInternalState : E_ControlState;
    tonWatchdog : TON;
END_VAR

(* Safety Monitor - Independent high-limit safety thermostats (redundant to PLC) *)
fbSafety(
    Enable := bEnable,
    EmergencyStop := bEmergencyStop,
    ProcessValue := rProcessValue,
    HighLimit := rSetpoint * 1.2,
    LowLimit := rSetpoint * 0.1
);

(* Main Control Logic *)
IF fbSafety.SafeToRun THEN
    (* Ramp Generator - Prevents startup surge *)
    fbRamp(
        Enable := bEnable,
        TargetValue := rSetpoint,
        RampRate := 20.0,  (* Process Control rate *)
        CurrentValue => rSetpoint
    );

    (* PID Controller - [object Object] *)
    fbPID(
        Enable := fbRamp.InPosition,
        ProcessValue := rProcessValue,
        Setpoint := fbRamp.CurrentValue,
        Kp := 1.0,
        Ki := 0.1,
        Kd := 0.05,
        OutputMin := 0.0,
        OutputMax := 100.0
    );

    rControlOutput := fbPID.Output;
    bRunning := TRUE;
    bFault := FALSE;
    nFaultCode := 0;

ELSE
    (* Safe State - Watchdog timers for heater control validity *)
    rControlOutput := 0.0;
    bRunning := FALSE;
    bFault := NOT bEnable;  (* Only fault if not intentional stop *)
    nFaultCode := fbSafety.FaultCode;
END_IF;

(* Diagnostics - Circular buffer with ST_LogRecord. Write index with modulo wrap. Triggered capture with pre/post samples. File export using file system library. *)
fbDiag(
    ProcessRunning := bRunning,
    FaultActive := bFault,
    ProcessValue := rProcessValue,
    ControlOutput := rControlOutput
);

(* Watchdog - Detects frozen control *)
tonWatchdog(IN := bRunning AND NOT fbPID.OutputChanging, PT := T#10S);
IF tonWatchdog.Q THEN
    bFault := TRUE;
    nFaultCode := 99;  (* Watchdog fault *)
END_IF;

(* Reset Logic *)
IF bReset AND NOT bEmergencyStop THEN
    bFault := FALSE;
    nFaultCode := 0;
    fbDiag.ClearAlarms();
END_IF;

END_FUNCTION_BLOCK

Code Explanation:

  • 1.Encapsulated function block follows Standard FB structure with VAR_INPUT/OUT - reusable across Process Control projects
  • 2.FB_SafetyMonitor provides Independent high-limit safety thermostats (redundant to PLC) including high/low limits
  • 3.FB_RampGenerator prevents startup issues common in Temperature Control systems
  • 4.FB_PIDController tuned for Process Control: Kp=1.0, Ki=0.1
  • 5.Watchdog timer detects frozen control - critical for intermediate Temperature Control reliability
  • 6.Diagnostic function block enables Circular buffer with ST_LogRecord. Write index with modulo wrap. Triggered capture with pre/post samples. File export using file system library. and ST_Alarm structure with bActive, bAcknowledged, dtActivation, nCode, sMessage. Array of alarms with detection and acknowledgment logic. Integration with ABB alarm libraries.

Best Practices

  • Follow ABB naming conventions: g_ prefix for globals. i_/q_ for FB I/O. Type prefixes: b=BOOL, n=INT, r=REAL, s
  • ABB function design: Standard FB structure with VAR_INPUT/OUTPUT/VAR. Methods extend functionality. A
  • Data organization: DUTs define structures. GVLs group related data. Retain attribute preserves vari
  • Function Blocks: Arrange blocks for clear left-to-right data flow
  • Function Blocks: Use consistent spacing and alignment for readability
  • Function Blocks: Label all inputs and outputs with meaningful names
  • Temperature Control: Sample at 1/10 of the process time constant minimum
  • Temperature Control: Use derivative on PV, not error, for temperature control
  • Temperature Control: Start with conservative tuning and tighten gradually
  • Debug with Automation Builder: Use structured logging to controller log
  • Safety: Independent high-limit safety thermostats (redundant to PLC)
  • Use Automation Builder simulation tools to test Temperature Control logic before deployment

Common Pitfalls to Avoid

  • Function Blocks: Creating feedback loops without proper initialization
  • Function Blocks: Connecting incompatible data types
  • Function Blocks: Not considering execution order dependencies
  • ABB common error: Exception 'AccessViolation': Null pointer access
  • Temperature Control: Long thermal time constants making tuning difficult
  • Temperature Control: Transport delay (dead time) causing instability
  • Neglecting to validate RTDs (PT100/PT1000) for high-accuracy measurements leads to control errors
  • Insufficient comments make Function Blocks programs unmaintainable over time

Related Certifications

🏆ABB Automation Certification
🏆Advanced ABB Programming Certification
Mastering Function Blocks for Temperature Control applications using ABB Automation Builder requires understanding both the platform's capabilities and the specific demands of Process Control. This guide has provided comprehensive coverage of implementation strategies, working code examples, best practices, and common pitfalls to help you succeed with intermediate Temperature Control projects. ABB's 8% market share and medium - strong in power generation, mining, and marine applications demonstrate the platform's capability for demanding applications. The platform excels in Process Control applications where Temperature Control reliability is critical. By following the practices outlined in this guide—from proper program structure and Function Blocks best practices to ABB-specific optimizations—you can deliver reliable Temperature Control systems that meet Process Control requirements. **Next Steps for Professional Development:** 1. **Certification**: Pursue ABB Automation Certification to validate your ABB expertise 3. **Hands-on Practice**: Build Temperature Control projects using AC500 hardware 4. **Stay Current**: Follow Automation Builder updates and new Function Blocks features **Function Blocks Foundation:** Function Block Diagram (FBD) is a graphical programming language where functions and function blocks are represented as boxes connected by signal line... The 2-3 weeks typical timeline for Temperature Control projects will decrease as you gain experience with these patterns and techniques. Remember: Sample at 1/10 of the process time constant minimum For further learning, explore related topics including Temperature control, Plastic molding machines, and ABB platform-specific features for Temperature Control optimization.