Inovance Structured Text for Pump Control: Complete Programming Guide

Implementing Structured Text for Pump Control using Inovance InoProShop / AutoShop requires a documented design, applicable standards, and project-specific acceptance criteria. This guide organizes practical checks for code structure, diagnostics, testing, and maintenance.

The example references AM600-family terminology, but model capabilities vary. Verify the controller manual, the installed InoProShop / AutoShop version, and any applicable machinery, process, electrical, or functional-safety requirements for the actual project.

Best practices for Pump Control encompass multiple dimensions: proper handling of 5 sensor types, safe control of 5 different actuators, managing pressure regulation, and ensuring compliance with relevant industry standards. The Structured Text approach, when properly implemented, provides powerful for complex logic and excellent code reusability, both critical for intermediate projects.

This guide presents a reviewable approach to Inovance Structured Text programming for Pump Control, covering code organization, documentation, test procedures, and maintenance handoff. The sample logic is educational and must be compiled, simulated, peer-reviewed, and tested against the project's acceptance criteria before use on equipment.

Inovance InoProShop / AutoShop for Pump Control

InoProShop / AutoShop is a programming environment associated with Inovance controller families such as AM600, AM610, H5U. This guide uses Structured Text terminology from the supplied guide dataset, but controller capabilities and language support can change by model, firmware, software edition, and license.

Verify Before You Start:

The selected controller supports the required Structured Text constructs

The project version matches the installed InoProShop / AutoShop release

Required communications, motion, safety, and simulation options are licensed

Firmware and device-description files are compatible with the project

The vendor manuals used for the design match the exact hardware revision

Application Planning:

For a Pump Control exercise, map the required inputs and outputs before writing logic. The example considers 5 sensor types, including Pressure transmitters, Flow meters, Level sensors, and 5 actuator types.

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

Controller-family references used in this guide include:

AM600: Confirm CPU, I/O, memory, communications, and Structured Text support in the current selection guide

AM610: Confirm CPU, I/O, memory, communications, and Structured Text support in the current selection guide

H5U: Confirm CPU, I/O, memory, communications, and Structured Text support in the current selection guide

AC800: Confirm CPU, I/O, memory, communications, and Structured Text support in the current selection guide

Hardware Selection Checklist:

Count local and remote I/O, including planned expansion

Measure the required task and communications update rates

Identify memory, data-retention, diagnostics, and cybersecurity requirements

Treat safety functions as a separate, standards-led design activity

Confirm lifecycle status, regional availability, licensing, and support

Source and Validation Note:

This page does not represent a vendor certification or a hardware acceptance test. Use current Inovance manuals, release notes, and safety documentation as the authority for product-specific behavior. Validate adapted logic in a simulator or isolated test setup before connecting it to equipment.

Investment Considerations:

For Pump Control projects, compare hardware, software licensing, training, engineering, test equipment, commissioning, spares, and ongoing support. Obtain current pricing and lifecycle information directly from the vendor or an authorized regional supplier.

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 Inovance InoProShop / AutoShop.

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 Inovance InoProShop / AutoShop 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 InoProShop / AutoShop, characterize pump curve and system curve.

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

In InoProShop / AutoShop, size vfd for application (constant torque vs. variable torque).

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

In InoProShop / AutoShop, implement primary control loop (pressure, flow, or level).

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

In InoProShop / AutoShop, add pump protection logic (minimum flow, temperature, seal).

Step 5: Program lead/lag sequencing with alternation

In InoProShop / AutoShop, program lead/lag sequencing with alternation.

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

In InoProShop / AutoShop, implement soft start/stop ramps for smooth operation.

Inovance Function Design:

InoProShop strongly favours function-block reuse via the Library Manager — Inovance ships standard libraries for motion, drives, HMI, OPC UA, and industry-specific applications (lithium-battery, EV, elevator). AutoShop reuse is open-coded via P-label subroutines. OEM machine-builders increasingly default to InoProShop / AM600 to access the FB libraries.

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:

Task and I/O timing: Record minimum, average, and maximum values under a defined test load

Accuracy: Define an acceptable tolerance and compare it with calibrated reference measurements

Throughput: Count completed cycles over a fixed interval and record rejected or incomplete cycles

Fault response: Measure detection, safe-state, alarm, and recovery behavior for each test case

Resource use: Record memory, communications load, and diagnostic-buffer behavior

Inovance Diagnostic Tools:

InoProShop online mode with full POU monitoring and breakpoint debug,EtherCAT diagnostics page with topology and slave status,Trace tool for analogue / motion signal capture,OPC UA server diagnostics page,Modbus communication trace utility,AutoShop online mode for legacy AC800 / Easy series,Inovance HMI integrated diagnostics for HMI-PLC binding faults,Servo-drive panel diagnostics with InoProShop drive-monitor view,EtherCAT slave-firmware update tool,Project compare tool for change tracking

Use the monitoring and diagnostic functions available in your InoProShop / AutoShop version, and record the software, firmware, hardware, workload, and test procedure with every result.

Inovance Structured Text Example for Pump Control

Illustrative Structured Text example for Pump Control using Inovance terminology. Adapt the syntax to your InoProShop / AutoShop release, compile it, and verify it in an isolated test environment before use on equipment.

(* Inovance InoProShop / AutoShop - Pump Control Control *)
(* Structured Text Implementation for Water & Wastewater *)
(* On InoProShop projects, conventions follow CODESYS / IEC norms — Pasca *)

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; (* Illustrative value; replace with a reviewed requirement *)
END_VAR

VAR CONSTANT
    (* Water & Wastewater Process Parameters *)
    C_DEBOUNCE_TIME : TIME := T#500MS;
    C_PROCESS_TIMEOUT : TIME := T#30S; (* Illustrative value; verify for the process *)
    C_BATCH_SIZE : INT := 50; (* Illustrative value; replace with a reviewed requirement *)
END_VAR

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

(* Main State Machine - Pattern: InoProShop state machines typically use  *)
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 - InoProShop on AM600 / H5U supports SD-card logging via library FBs, plus OPC UA streaming for cloud / on-premises historians. Inovance HMIs add CSV logging at HMI tier. AutoShop projects rely on HMI-tier logging exclusively. *)
        eState := IDLE;

    FAULT:
        rCentrifugalpumps := 0.0;
        (* InoProShop alarms are typically defined in the visualisation alarm-configuration page with severity, latching, and acknowledgement behaviour configured per alarm. The runtime maintains active and historical alarm lists. AutoShop projects fall back to M-flag banks with HMI-side alarm logging. *)
        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 (InoProShop state machines typically use IEC SFC steps with action blocks per step, or a state-enum-and-CASE pattern in Structured Text. SFC dominates production-line sequencers; CASE patterns dominate axis-control state and recipe-routing logic. AutoShop projects fall back to FX-style SFC step memory (S0..S511) or D-register integer state.) for clear Pump Control sequence control
2.Constants use clearly marked illustrative values that must be replaced with reviewed project requirements
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 flags a possible stuck condition for investigation
6.The final override illustrates a software permissive only; it is not a safety-rated function and must not replace a validated safety system

Best Practices

✓Follow Inovance naming conventions: On InoProShop projects, conventions follow CODESYS / IEC norms — PascalCase for
✓Inovance function design: InoProShop strongly favours function-block reuse via the Library Manager — Inova
✓Data organization: InoProShop uses GVLs and persistent variables for shared data. AutoShop uses D /
✓Structured Text: Use meaningful variable names with consistent naming conventions
✓Structured Text: Initialize all variables at declaration to prevent undefined behavior
✓Structured Text: Use enumerated types for state machines instead of magic numbers
✓Pump Control: Use PID with derivative on PV for pressure control
✓Pump Control: Implement soft start ramps even with VFD (200-500ms)
✓Pump Control: Add flow proving before considering pump operational
✓Debug with InoProShop / AutoShop: Use InoProShop's online mode to set breakpoints in POUs and step throu
✓Safety: Dry run protection using flow or level monitoring
✓Use a compatible simulator or isolated test rig 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
⚠Inovance common error: EtherCAT slave order mismatch after physical re-cabling — slave addressing break
⚠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

🏆Inovance Certified Engineer

🏆InoProShop / AutoShop training certificates

🏆EV / Lithium Battery automation specialist tracks

🏆Advanced Inovance Programming Certification

Applying Structured Text to Pump Control using Inovance InoProShop / AutoShop requires understanding the platform, the process, and the project's acceptance criteria. This guide has covered implementation structure, an illustrative code example, verification practices, and common pitfalls for a intermediate Pump Control exercise.

Use the practices outlined here to create a design that can be reviewed and tested. Define performance targets in the project requirements and confirm them with repeatable measurements.

Next Steps:

1. Check Sources: Read the current InoProShop / AutoShop help, controller manual, release notes, and relevant standards
2. Practice Safely: Adapt the example in a simulator or isolated training setup
3. Review: Have the I/O map, state behavior, faults, and recovery steps reviewed
4. Test: Record normal, boundary, fault, restart, and communications test results

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...

Project duration depends on scope, reviews, hardware availability, software and firmware versions, testing, commissioning, and site constraints. Remember: Use PID with derivative on PV for pressure control

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