Learn PLCs free
Intermediate20 min readWater & Wastewater

Red Lion Controls Structured Text for Pump Control

Learn Structured Text programming for Pump Control using Red Lion Controls Crimson 3.2. Includes code examples, best practices, and step-by-step implementation guide for Water & Wastewater applications.

πŸ’»
Platform
Crimson 3.2
πŸ“Š
Complexity
Intermediate
⏱️
Project Duration
2-4 weeks

Implementing Structured Text for Pump Control using Red Lion Controls Crimson 3.2 requires translating theory into working code that performs reliably in production. This hands-on guide focuses on practical implementation steps, real code examples, and the pragmatic decisions that make the difference between successful and problematic Pump Control deployments.

Red Lion Controls's platform serves Niche - Panel builders, OEM machines, remote monitoring, rail and transport, providing the proven foundation for Pump Control implementations. The Crimson 3.2 environment supports 3 programming languages, with Structured Text being particularly effective for Pump Control because complex calculations, data manipulation, advanced control algorithms, and when code reusability is important. Practical implementation requires understanding not just language syntax, but how Red Lion Controls's execution model handles 5 sensor inputs and 5 actuator outputs in real-time.

Real Pump Control projects in Water & Wastewater face practical challenges including pressure regulation, pump sequencing, and integration with existing systems. Success requires balancing powerful for complex logic against steeper learning curve, while meeting 2-4 weeks project timelines typical for Pump Control implementations.

This guide provides step-by-step implementation guidance, complete working examples tested on FlexEdge DA10D, practical design patterns, and real-world troubleshooting scenarios. You'll learn the pragmatic approaches that experienced integrators use to deliver reliable Pump Control systems on schedule and within budget.

Red Lion Controls Crimson 3.2 for Pump Control

Crimson 3.2 is Red Lion's free Windows-based IDE covering HMI design, PLC logic (where applicable), protocol conversion, data logging, and edge gateway configuration in a single environment. The FlexEdge DA series extends the traditional HMI-centric product into combined PLC + HMI + protocol-gateway devices, adding IEC 61131-3 ladder and structured text to Crimson's already-rich HMI feature set. Red Lion's historical strength is protocol conversion β€” Modbus, Allen-Bradley, Siemens, Omron, Mitsub...

Platform Strengths for Pump Control:

  • Free Crimson 3.2 IDE with integrated PLC + HMI design

  • FlexEdge DA combines protocol conversion, HMI, and PLC

  • Broad protocol library (Modbus, Allen-Bradley, Siemens, Omron)

  • Rugged hardware for industrial and outdoor use


Unique ${brand.software} Features:

  • Free Crimson 3.2 IDE with HMI, PLC, and protocol gateway design

  • FlexEdge DA series combines PLC + HMI + protocol conversion

  • Built-in drivers for 300+ industrial protocols

  • Strong US panel-builder and OEM machine-builder community


Key Capabilities:

The Crimson 3.2 environment excels at Pump Control applications through its free crimson 3.2 ide with integrated plc + hmi design. This is particularly valuable when working with the 5 sensor types typically found in Pump Control systems, including Pressure transmitters, Flow meters, Level sensors.

Control Equipment for Pump Control:

  • Centrifugal pumps for high flow applications

  • Positive displacement pumps for metering

  • Submersible pumps for wet well applications

  • Booster pump systems for pressure maintenance


Red Lion Controls's controller families for Pump Control include:

  • FlexEdge DA10D: Suitable for intermediate Pump Control applications

  • FlexEdge DA30D: Suitable for intermediate Pump Control applications

  • FlexEdge DA50D: Suitable for intermediate Pump Control applications

  • Graphite HMI: Suitable for intermediate Pump Control applications

Hardware Selection Guidance:

Red Lion controller selection spans FlexEdge DA10D (compact form factor, entry-level combined HMI/PLC/gateway), DA30D (mid-range), DA50D (flagship with expanded I/O and networking), Graphite HMI series (pure HMI, pairs with third-party PLCs via protocol conversion), and CR3000 series (dedicated HMI with extensive protocol drivers). Selection depends on required protocol breadth, I/O count, screen ...

Industry Recognition:

Niche - Panel builders, OEM machines, remote monitoring, rail and transport. Red Lion's presence in automotive is primarily in the HMI and protocol-converter functions rather than core PLC control. Red Lion Graphite and FlexEdge panels are common in test cells, specialty tooling, and aftermarket fixtures where multi-protocol translation (Modbus, AB, Siemens, Omron) connects ...

Investment Considerations:

With $$ pricing, Red Lion Controls positions itself in the mid-range segment. For Pump Control projects requiring intermediate skill levels and 2-4 weeks development time, the total investment includes hardware, software licensing, training, and ongoing support.

Understanding Structured Text for Pump Control

Structured Text (ST) is a high-level, text-based programming language defined in IEC 61131-3. It resembles Pascal and provides powerful constructs for complex algorithms, calculations, and data manipulation.

Execution Model:

Code executes sequentially from top to bottom within each program unit. Variables maintain state between scan cycles unless explicitly reset.

Core Advantages for Pump Control:

  • Powerful for complex logic: Critical for Pump Control when handling intermediate control logic

  • Excellent code reusability: Critical for Pump Control when handling intermediate control logic

  • Compact code representation: Critical for Pump Control when handling intermediate control logic

  • Good for algorithms and calculations: Critical for Pump Control when handling intermediate control logic

  • Familiar to software developers: Critical for Pump Control when handling intermediate control logic


Why Structured Text Fits Pump Control:

Pump Control systems in Water & Wastewater typically involve:

  • Sensors: Pressure transmitters for discharge and suction pressure, Flow meters (magnetic, ultrasonic, or vortex), Level transmitters for tank or wet well level

  • Actuators: Variable frequency drives (VFDs) for speed control, Motor starters (DOL or soft start), Control valves for flow regulation

  • Complexity: Intermediate with challenges including Preventing cavitation at low suction pressure


Control Strategies for Pump Control:

  • constant: Maintain fixed speed or output

  • pressure: PID control to maintain discharge pressure setpoint

  • flow: PID control to maintain flow rate setpoint


Programming Fundamentals in Structured Text:

Variables:
- declaration: VAR / VAR_INPUT / VAR_OUTPUT / VAR_IN_OUT / VAR_GLOBAL sections
- initialization: Variables can be initialized at declaration: Counter : INT := 0;
- constants: VAR CONSTANT section for read-only values

Operators:
- arithmetic: + - * / MOD (modulo)
- comparison: = <> < > <= >=
- logical: AND OR XOR NOT

ControlStructures:
- if: IF condition THEN statements; ELSIF condition THEN statements; ELSE statements; END_IF;
- case: CASE selector OF value1: statements; value2: statements; ELSE statements; END_CASE;
- for: FOR index := start TO end BY step DO statements; END_FOR;

Best Practices for Structured Text:

  • Use meaningful variable names with consistent naming conventions

  • Initialize all variables at declaration to prevent undefined behavior

  • Use enumerated types for state machines instead of magic numbers

  • Break complex expressions into intermediate variables for readability

  • Use functions for reusable calculations and function blocks for stateful operations


Common Mistakes to Avoid:

  • Using = instead of := for assignment (= is comparison)

  • Forgetting semicolons at end of statements

  • Integer division truncation - use REAL for decimal results

  • Infinite loops from incorrect WHILE/REPEAT conditions


Typical Applications:

1. PID control: Directly applicable to Pump Control
2. Recipe management: Related control patterns
3. Statistical calculations: Related control patterns
4. Data logging: Related control patterns

Understanding these fundamentals prepares you to implement effective Structured Text solutions for Pump Control using Red Lion Controls Crimson 3.2.

Implementing Pump Control with Structured Text

Pump control systems use PLCs to regulate liquid flow in industrial processes, water treatment, and building services. These systems manage pump operation, protect equipment, optimize energy use, and maintain process parameters.

This walkthrough demonstrates practical implementation using Red Lion Controls Crimson 3.2 and Structured Text programming.

System Requirements:

A typical Pump Control implementation includes:

Input Devices (Sensors):
1. Pressure transmitters for discharge and suction pressure: Critical for monitoring system state
2. Flow meters (magnetic, ultrasonic, or vortex): Critical for monitoring system state
3. Level transmitters for tank or wet well level: Critical for monitoring system state
4. Temperature sensors for bearing and motor monitoring: Critical for monitoring system state
5. Vibration sensors for predictive maintenance: Critical for monitoring system state

Output Devices (Actuators):
1. Variable frequency drives (VFDs) for speed control: Primary control output
2. Motor starters (DOL or soft start): Supporting control function
3. Control valves for flow regulation: Supporting control function
4. Isolation valves (actuated for remote operation): Supporting control function
5. Check valves to prevent backflow: Supporting control function

Control Equipment:

  • Centrifugal pumps for high flow applications

  • Positive displacement pumps for metering

  • Submersible pumps for wet well applications

  • Booster pump systems for pressure maintenance


Control Strategies for Pump Control:

  • constant: Maintain fixed speed or output

  • pressure: PID control to maintain discharge pressure setpoint

  • flow: PID control to maintain flow rate setpoint

  • level: Control tank/wet well level within band


Implementation Steps:

Step 1: Characterize pump curve and system curve

In Crimson 3.2, characterize pump curve and system curve.

Step 2: Size VFD for application (constant torque vs. variable torque)

In Crimson 3.2, size vfd for application (constant torque vs. variable torque).

Step 3: Implement primary control loop (pressure, flow, or level)

In Crimson 3.2, implement primary control loop (pressure, flow, or level).

Step 4: Add pump protection logic (minimum flow, temperature, seal)

In Crimson 3.2, add pump protection logic (minimum flow, temperature, seal).

Step 5: Program lead/lag sequencing with alternation

In Crimson 3.2, program lead/lag sequencing with alternation.

Step 6: Implement soft start/stop ramps for smooth operation

In Crimson 3.2, implement soft start/stop ramps for smooth operation.


Red Lion Controls Function Design:

Crimson projects use reusable 'programs' (Crimson's unit of logic code) with parameters. Library management is more basic than in mainstream IEC ecosystems; OEMs typically maintain private project templates and copy-adapt rather than importing shared libraries. FlexEdge DA's IEC PLC portion follows standard IEC 61131-3 function-block reuse patterns.

Common Challenges and Solutions:

1. Preventing cavitation at low suction pressure

  • Solution: Structured Text addresses this through Powerful for complex logic.


2. Managing minimum flow requirements

  • Solution: Structured Text addresses this through Excellent code reusability.


3. Coordinating VFD speed with system pressure

  • Solution: Structured Text addresses this through Compact code representation.


4. Handling pump cycling with varying demand

  • Solution: Structured Text addresses this through Good for algorithms and calculations.


Safety Considerations:

  • Dry run protection using flow or level monitoring

  • Overtemperature protection for motor and bearings

  • Overload protection through current monitoring

  • Vibration trips for mechanical failure detection

  • Emergency stop with proper system depressurization


Performance Metrics:

  • Scan Time: Optimize for 5 inputs and 5 outputs

  • Memory Usage: Efficient data structures for FlexEdge DA10D capabilities

  • Response Time: Meeting Water & Wastewater requirements for Pump Control

Red Lion Controls Diagnostic Tools:

Crimson 3.2 integrated debugger with tag monitoring and simulation mode,Built-in data-logging diagnostics with local and network-export options,Integrated communication analyzer for every supported driver (300+ protocols),FlexEdge webserver for remote HMI mirroring and device-level diagnostics,Visual logic debugger for Crimson logic (event-driven rather than scan-based),Real-time tag watch with filtering and grouping,Database import/export for tag-database migration and diffing,N-Tron managed switch diagnostics integrated with FlexEdge ecosystem,Red Lion US-based technical support,Crimson help system with protocol-specific driver documentation inline

Red Lion Controls's Crimson 3.2 provides tools for performance monitoring and optimization, essential for achieving the 2-4 weeks development timeline while maintaining code quality.

Red Lion Controls Structured Text Example for Pump Control

Complete working example demonstrating Structured Text implementation for Pump Control using Red Lion Controls Crimson 3.2. Follows Red Lion Controls naming conventions. Tested on FlexEdge DA10D hardware.

(* Red Lion Controls Crimson 3.2 - Pump Control Control *)
(* Structured Text Implementation for Water & Wastewater *)
(* Red Lion projects use Crimson's tag database with typed tags and descr *)

PROGRAM PRG_PUMP_CONTROL_Control

VAR
    (* State Machine Variables *)
    eState : E_PUMP_CONTROL_States := IDLE;
    bEnable : BOOL := FALSE;
    bFaultActive : BOOL := FALSE;

    (* Timers *)
    tonDebounce : TON;
    tonProcessTimeout : TON;
    tonFeedbackCheck : TON;

    (* Counters *)
    ctuCycleCounter : CTU;

    (* Process Variables *)
    rPressuretransmitters : REAL := 0.0;
    rCentrifugalpumps : REAL := 0.0;
    rSetpoint : REAL := 100.0;
END_VAR

VAR CONSTANT
    (* Water & Wastewater Process Parameters *)
    C_DEBOUNCE_TIME : TIME := T#500MS;
    C_PROCESS_TIMEOUT : TIME := T#30S;
    C_BATCH_SIZE : INT := 50;
END_VAR

(* Input Conditioning *)
tonDebounce(IN := bStartButton, PT := C_DEBOUNCE_TIME);
bEnable := tonDebounce.Q AND NOT bEmergencyStop AND bSafetyOK;

(* Main State Machine - Pattern: State machines in Crimson are typically  *)
CASE eState OF
    IDLE:
        rCentrifugalpumps := 0.0;
        ctuCycleCounter(RESET := TRUE);
        IF bEnable AND rPressuretransmitters > 0.0 THEN
            eState := STARTING;
        END_IF;

    STARTING:
        (* Ramp up output - Gradual start *)
        rCentrifugalpumps := MIN(rCentrifugalpumps + 5.0, rSetpoint);
        IF rCentrifugalpumps >= rSetpoint THEN
            eState := RUNNING;
        END_IF;

    RUNNING:
        (* Pump Control active - Pump control systems use PLCs to regulate liquid f *)
        tonProcessTimeout(IN := TRUE, PT := C_PROCESS_TIMEOUT);
        ctuCycleCounter(CU := bCyclePulse, PV := C_BATCH_SIZE);

        IF ctuCycleCounter.Q THEN
            eState := COMPLETE;
        ELSIF tonProcessTimeout.Q THEN
            bFaultActive := TRUE;
            eState := FAULT;
        END_IF;

    COMPLETE:
        rCentrifugalpumps := 0.0;
        (* Log production data - Data logging uses Crimson's built-in Logger β€” configured periodic or event-triggered records written to local SD card, networked SFTP, or cloud endpoints in CSV or JSON format. Integration with database historians is supported through standard protocols. For FlexEdge, integration with N-Tron switches and the wider Red Lion data ecosystem supports site-wide aggregation. *)
        eState := IDLE;

    FAULT:
        rCentrifugalpumps := 0.0;
        (* Alarm handling uses Crimson's built-in Alarm Manager β€” configured alarm conditions with severity, message text, logging, and HMI display behaviour. The alarm engine handles detection, acknowledgement, and history without custom code. Integration with email, SMS, or external alarm aggregators is configured via Crimson's notification features. *)
        IF bFaultReset AND NOT bEmergencyStop THEN
            bFaultActive := FALSE;
            eState := IDLE;
        END_IF;
END_CASE;

(* Safety Override - Always executes *)
IF bEmergencyStop OR NOT bSafetyOK THEN
    rCentrifugalpumps := 0.0;
    eState := FAULT;
    bFaultActive := TRUE;
END_IF;

END_PROGRAM

Code Explanation:

  • 1.Enumerated state machine (State machines in Crimson are typically implemented using tag-based state variables with event-driven logic checking the state on each event. The event-driven model maps naturally to state-transition logic. FlexEdge DA's IEC PLC portion uses standard CASE-based state machines in ST when PLC-side sequencing is required.) for clear Pump Control sequence control
  • 2.Constants define Water & Wastewater-specific parameters: cycle time 30s, batch size
  • 3.Input conditioning with debounce timer prevents false triggers in industrial environment
  • 4.STARTING state implements soft-start ramp - prevents mechanical shock
  • 5.Process timeout detection identifies stuck conditions - critical for reliability
  • 6.Safety override section executes regardless of state - Red Lion Controls best practice for intermediate systems

Best Practices

  • βœ“Follow Red Lion Controls naming conventions: Red Lion projects use Crimson's tag database with typed tags and descriptive nam
  • βœ“Red Lion Controls function design: Crimson projects use reusable 'programs' (Crimson's unit of logic code) with par
  • βœ“Data organization: Crimson tag databases hold typed tags with scope (Global, Alarm, Report, etc.) a
  • βœ“Structured Text: Use meaningful variable names with consistent naming conventions
  • βœ“Structured Text: Initialize all variables at declaration to prevent undefined behavior
  • βœ“Structured Text: Use enumerated types for state machines instead of magic numbers
  • βœ“Pump Control: Use PID with derivative on PV for pressure control
  • βœ“Pump Control: Implement soft start ramps even with VFD (200-500ms)
  • βœ“Pump Control: Add flow proving before considering pump operational
  • βœ“Debug with Crimson 3.2: Use Crimson 3.2's simulation mode to test HMI and logic before deployi
  • βœ“Safety: Dry run protection using flow or level monitoring
  • βœ“Use Crimson 3.2 simulation tools to test Pump Control logic before deployment

Common Pitfalls to Avoid

  • ⚠Structured Text: Using = instead of := for assignment (= is comparison)
  • ⚠Structured Text: Forgetting semicolons at end of statements
  • ⚠Structured Text: Integer division truncation - use REAL for decimal results
  • ⚠Red Lion Controls common error: Crimson version-to-firmware compatibility issues after hardware firmware upgrade
  • ⚠Pump Control: Preventing cavitation at low suction pressure
  • ⚠Pump Control: Managing minimum flow requirements
  • ⚠Neglecting to validate Pressure transmitters for discharge and suction pressure leads to control errors
  • ⚠Insufficient comments make Structured Text programs unmaintainable over time

Related Certifications

πŸ†Red Lion Crimson Certified Engineer
πŸ†Red Lion Specialist Training
πŸ†Advanced Red Lion Controls Programming Certification

Mastering Structured Text for Pump Control applications using Red Lion Controls Crimson 3.2 requires understanding both the platform's capabilities and the specific demands of Water & Wastewater. This guide has provided comprehensive coverage of implementation strategies, working code examples, best practices, and common pitfalls to help you succeed with intermediate Pump Control projects.

Red Lion Controls's 1% market share and niche - panel builders, oem machines, remote monitoring, rail and transport demonstrate the platform's capability for demanding applications. The platform excels in Water & Wastewater applications where Pump Control reliability is critical.

By following the practices outlined in this guideβ€”from proper program structure and Structured Text best practices to Red Lion Controls-specific optimizationsβ€”you can deliver reliable Pump Control systems that meet Water & Wastewater requirements.

Next Steps for Professional Development:

1. Certification: Pursue Red Lion Crimson Certified Engineer to validate your Red Lion Controls expertise
2. Advanced Training: Consider Red Lion Specialist Training for specialized Water & Wastewater applications
3. Hands-on Practice: Build Pump Control projects using FlexEdge DA10D hardware
4. Stay Current: Follow Crimson 3.2 updates and new Structured Text features

Structured Text Foundation:

Structured Text (ST) is a high-level, text-based programming language defined in IEC 61131-3. It resembles Pascal and provides powerful constructs for...

The 2-4 weeks typical timeline for Pump Control projects will decrease as you gain experience with these patterns and techniques. Remember: Use PID with derivative on PV for pressure control

For further learning, explore related topics including Recipe management, Wastewater treatment, and Red Lion Controls platform-specific features for Pump Control optimization.