Implementing Timers for Pump Control using Unitronics VisiLogic / UniLogic requires adherence to industry standards and proven best practices from Water & Wastewater. This guide compiles best practices from successful Pump Control deployments, Unitronics programming standards, and Water & Wastewater requirements to help you deliver professional-grade automation solutions.
Unitronics's position as Moderate - US small-integrator market, OEM machines, building automation means their platforms must meet rigorous industry requirements. Companies like Jazz 2 users in municipal water systems and wastewater treatment have established proven patterns for Timers implementation that balance functionality, maintainability, and safety.
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 Timers approach, when properly implemented, provides simple to implement and highly reliable, both critical for intermediate projects.
This guide presents industry-validated approaches to Unitronics Timers programming for Pump Control, covering code organization standards, documentation requirements, testing procedures, and maintenance best practices. You'll learn how leading companies structure their Pump Control programs, handle error conditions, and ensure long-term reliability in production environments.
Unitronics VisiLogic / UniLogic for Pump Control
Unitronics takes a distinctive approach to PLC programming: every controller ships with an integrated colour touchscreen HMI, and the development tool handles PLC logic and HMI design in a single workspace. VisiLogic is the legacy tool for the Vision, Samba, and Jazz product families; UniLogic is the current-generation environment for the UniStream line. Both are free to download and include a complete built-in simulator covering PLC logic, HMI screens, alarms, recipes, and data tables — the sim...
Platform Strengths for Pump Control:
- Combined PLC + HMI in one unit reduces panel cost
- Free VisiLogic and UniLogic IDEs
- Built-in simulator with both PLC and HMI simulation
- Strong US small-integrator community
Unique ${brand.software} Features:
- Combined PLC + HMI in one unit across Jazz, Samba, Vision, and UniStream
- Free VisiLogic (legacy) and UniLogic (current) IDEs
- Built-in simulator covering PLC logic, HMI, alarms, data tables, and recipes
- Integrated data sampling and trend logging without separate SCADA
Key Capabilities:
The VisiLogic / UniLogic environment excels at Pump Control applications through its combined plc + hmi in one unit reduces panel cost. 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
Unitronics's controller families for Pump Control include:
- Jazz 2: Suitable for intermediate Pump Control applications
- Samba 7": Suitable for intermediate Pump Control applications
- Vision V350: Suitable for intermediate Pump Control applications
- Vision V570: Suitable for intermediate Pump Control applications
Hardware Selection Guidance:
CPU selection across Unitronics ranges from the Jazz 2 micro series (tiny applications, basic motor control, simple process monitoring with 10-20 I/O) through Samba 7" (small machine control with touchscreen HMI), Vision V350/V570 (medium machinery with larger HMI), and UniStream 7" / 15.6" (flagship combined PLC+HMI for mid-to-high complexity applications with advanced features like UniCloud, cel...
Industry Recognition:
Moderate - US small-integrator market, OEM machines, building automation. Unitronics' combined PLC+HMI controllers are uncommon in high-volume automotive manufacturing but appear in automotive tier-2 and tier-3 supplier shops, single-machine workcells, and after-market test fixtures. The cost advantage and single-unit PLC+HMI approach makes Unitronics attractive for small...
Investment Considerations:
With $$ pricing, Unitronics 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 Timers for Pump Control
PLC timers measure elapsed time to implement delays, pulses, and timed operations. They use accumulated time compared against preset values to control outputs.
Execution Model:
For Pump Control applications, Timers offers significant advantages when any application requiring time delays, time-based sequencing, or time monitoring.
Core Advantages for Pump Control:
- Simple to implement: Critical for Pump Control when handling intermediate control logic
- Highly reliable: Critical for Pump Control when handling intermediate control logic
- Essential for most applications: Critical for Pump Control when handling intermediate control logic
- Easy to troubleshoot: Critical for Pump Control when handling intermediate control logic
- Widely supported: Critical for Pump Control when handling intermediate control logic
Why Timers 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 Timers:
Timers in VisiLogic / UniLogic follows these key principles:
1. Structure: Timers organizes code with highly reliable
2. Execution: Scan cycle integration ensures 5 sensor inputs are processed reliably
3. Data Handling: Proper data types for 5 actuator control signals
Best Practices for Timers:
- Use constants or parameters for preset times - avoid hardcoded values
- Add timer status to HMI for operator visibility
- Implement timeout timers for fault detection in sequences
- Use appropriate timer resolution for the application
- Document expected timer values in comments
Common Mistakes to Avoid:
- Using TON when TOF behavior is needed or vice versa
- Not resetting RTO timers, causing unexpected timeout
- Timer preset too short relative to scan time causing missed timing
- Using software timers for safety-critical timing
Typical Applications:
1. Motor start delays: Directly applicable to Pump Control
2. Alarm delays: Related control patterns
3. Process timing: Related control patterns
4. Conveyor sequencing: Related control patterns
Understanding these fundamentals prepares you to implement effective Timers solutions for Pump Control using Unitronics VisiLogic / UniLogic.
Implementing Pump Control with Timers
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 Unitronics VisiLogic / UniLogic and Timers 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 VisiLogic / UniLogic, characterize pump curve and system curve.
Step 2: Size VFD for application (constant torque vs. variable torque)
In VisiLogic / UniLogic, size vfd for application (constant torque vs. variable torque).
Step 3: Implement primary control loop (pressure, flow, or level)
In VisiLogic / UniLogic, implement primary control loop (pressure, flow, or level).
Step 4: Add pump protection logic (minimum flow, temperature, seal)
In VisiLogic / UniLogic, add pump protection logic (minimum flow, temperature, seal).
Step 5: Program lead/lag sequencing with alternation
In VisiLogic / UniLogic, program lead/lag sequencing with alternation.
Step 6: Implement soft start/stop ramps for smooth operation
In VisiLogic / UniLogic, implement soft start/stop ramps for smooth operation.
Unitronics Function Design:
Function block design in Unitronics uses user-defined FBs in UniLogic (more limited in VisiLogic). Extensive vendor-provided helper FBs cover common tasks (PID, motion, communication, HMI utilities). OEM machine builders typically maintain private FB libraries for their common machine patterns, though code reuse is less mature than in mainstream PLC ecosystems.
Common Challenges and Solutions:
1. Preventing cavitation at low suction pressure
- Solution: Timers addresses this through Simple to implement.
2. Managing minimum flow requirements
- Solution: Timers addresses this through Highly reliable.
3. Coordinating VFD speed with system pressure
- Solution: Timers addresses this through Essential for most applications.
4. Handling pump cycling with varying demand
- Solution: Timers addresses this through Easy to troubleshoot.
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 Jazz 2 capabilities
- Response Time: Meeting Water & Wastewater requirements for Pump Control
Unitronics Diagnostic Tools:
UniLogic (current) and VisiLogic (legacy) integrated debuggers with breakpoints,Built-in simulator covering PLC logic, HMI screens, alarms, recipes, and data tables,Web visualisation for UniStream — remote HMI viewing without additional software,SD card logging with PC-side export tools for offline trend analysis,Modbus RTU/TCP transaction logging built into the IDE,Controller status monitor — CPU load, scan time, memory usage,HMI event logger capturing operator actions for audit purposes,CAN bus diagnostic tools for CANopen-equipped models,Remote support tool — Unitronics' own screen-sharing for technical support,User community forum with active troubleshooting discussions
Unitronics's VisiLogic / UniLogic provides tools for performance monitoring and optimization, essential for achieving the 2-4 weeks development timeline while maintaining code quality.
Unitronics Timers Example for Pump Control
Complete working example demonstrating Timers implementation for Pump Control using Unitronics VisiLogic / UniLogic. Follows Unitronics naming conventions. Tested on Jazz 2 hardware.
// Unitronics VisiLogic / UniLogic - Pump Control Control
// Timers Implementation for Water & Wastewater
// Unitronics projects use IDE-managed tag names rather than ra
// ============================================
// Variable Declarations
// ============================================
VAR
bEnable : BOOL := FALSE;
bEmergencyStop : BOOL := FALSE;
rPressuretransmitters : REAL;
rCentrifugalpumps : REAL;
END_VAR
// ============================================
// Input Conditioning - Pressure transmitters for discharge and suction pressure
// ============================================
// Standard input processing
IF rPressuretransmitters > 0.0 THEN
bEnable := TRUE;
END_IF;
// ============================================
// Safety Interlock - Dry run protection using flow or level monitoring
// ============================================
IF bEmergencyStop THEN
rCentrifugalpumps := 0.0;
bEnable := FALSE;
END_IF;
// ============================================
// Main Pump Control Control Logic
// ============================================
IF bEnable AND NOT bEmergencyStop THEN
// Pump control systems use PLCs to regulate liquid flow in ind
rCentrifugalpumps := rPressuretransmitters * 1.0;
// Process monitoring
// Add specific control logic here
ELSE
rCentrifugalpumps := 0.0;
END_IF;Code Explanation:
- 1.Timers structure optimized for Pump Control in Water & Wastewater applications
- 2.Input conditioning handles Pressure transmitters for discharge and suction pressure signals
- 3.Safety interlock ensures Dry run protection using flow or level monitoring always takes priority
- 4.Main control implements Pump control systems use PLCs to regulat
- 5.Code runs every scan cycle on Jazz 2 (typically 5-20ms)
Best Practices
- ✓Follow Unitronics naming conventions: Unitronics projects use IDE-managed tag names rather than raw memory addressing.
- ✓Unitronics function design: Function block design in Unitronics uses user-defined FBs in UniLogic (more limi
- ✓Data organization: Unitronics uses its own tag database concept rather than IEC-standard data block
- ✓Timers: Use constants or parameters for preset times - avoid hardcoded values
- ✓Timers: Add timer status to HMI for operator visibility
- ✓Timers: Implement timeout timers for fault detection in sequences
- ✓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 VisiLogic / UniLogic: Use the built-in simulator to reproduce issues before hardware visit
- ✓Safety: Dry run protection using flow or level monitoring
- ✓Use VisiLogic / UniLogic simulation tools to test Pump Control logic before deployment
Common Pitfalls to Avoid
- ⚠Timers: Using TON when TOF behavior is needed or vice versa
- ⚠Timers: Not resetting RTO timers, causing unexpected timeout
- ⚠Timers: Timer preset too short relative to scan time causing missed timing
- ⚠Unitronics common error: VisiLogic-to-UniLogic migration issues — not all projects convert cleanly
- ⚠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 Timers programs unmaintainable over time
Related Certifications
Mastering Timers for Pump Control applications using Unitronics VisiLogic / UniLogic 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.
Unitronics's 1% market share and moderate - us small-integrator market, oem machines, building automation 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 guide—from proper program structure and Timers best practices to Unitronics-specific optimizations—you can deliver reliable Pump Control systems that meet Water & Wastewater requirements.
Next Steps for Professional Development:
1. Certification: Pursue Unitronics Certified Integrator to validate your Unitronics expertise
2. Advanced Training: Consider UniLogic Developer Training for specialized Water & Wastewater applications
3. Hands-on Practice: Build Pump Control projects using Jazz 2 hardware
4. Stay Current: Follow VisiLogic / UniLogic updates and new Timers features
Timers Foundation:
PLC timers measure elapsed time to implement delays, pulses, and timed operations. They use accumulated time compared against preset values to control...
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 Alarm delays, Wastewater treatment, and Unitronics platform-specific features for Pump Control optimization.