Mastering advanced Timers techniques for Conveyor Systems in Unitronics's VisiLogic / UniLogic unlocks capabilities beyond basic implementations. This guide explores sophisticated programming patterns, optimization strategies, and advanced features that separate expert Unitronics programmers from intermediate practitioners in Material Handling applications.
Unitronics's VisiLogic / UniLogic contains powerful advanced features that many programmers never fully utilize. With 1% market share and deployment in demanding applications like airport baggage handling and warehouse distribution, Unitronics has developed advanced capabilities specifically for beginner to intermediate projects requiring simple to implement and highly reliable.
Advanced Conveyor Systems implementations leverage sophisticated techniques including multi-sensor fusion algorithms, coordinated multi-actuator control, and intelligent handling of product tracking. When implemented using Timers, these capabilities are achieved through delays patterns that exploit Unitronics-specific optimizations.
This guide reveals advanced programming techniques used by expert Unitronics programmers, including custom function blocks, optimized data structures, advanced Timers patterns, and VisiLogic / UniLogic-specific features that deliver superior performance. You'll learn implementation strategies that go beyond standard documentation, based on years of practical experience with Conveyor Systems systems in production Material Handling environments.
Unitronics VisiLogic / UniLogic for Conveyor Systems
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 Conveyor Systems:
- 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 Conveyor Systems 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 Conveyor Systems systems, including Photoelectric sensors, Proximity sensors, Encoders.
Control Equipment for Conveyor Systems:
- Belt conveyors with motor-driven pulleys
- Roller conveyors (powered and gravity)
- Modular plastic belt conveyors
- Accumulation conveyors (zero-pressure, minimum-pressure)
Unitronics's controller families for Conveyor Systems include:
- Jazz 2: Suitable for beginner to intermediate Conveyor Systems applications
- Samba 7": Suitable for beginner to intermediate Conveyor Systems applications
- Vision V350: Suitable for beginner to intermediate Conveyor Systems applications
- Vision V570: Suitable for beginner to intermediate Conveyor Systems 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 Conveyor Systems projects requiring beginner skill levels and 1-3 weeks development time, the total investment includes hardware, software licensing, training, and ongoing support.
Understanding Timers for Conveyor Systems
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 Conveyor Systems applications, Timers offers significant advantages when any application requiring time delays, time-based sequencing, or time monitoring.
Core Advantages for Conveyor Systems:
- Simple to implement: Critical for Conveyor Systems when handling beginner to intermediate control logic
- Highly reliable: Critical for Conveyor Systems when handling beginner to intermediate control logic
- Essential for most applications: Critical for Conveyor Systems when handling beginner to intermediate control logic
- Easy to troubleshoot: Critical for Conveyor Systems when handling beginner to intermediate control logic
- Widely supported: Critical for Conveyor Systems when handling beginner to intermediate control logic
Why Timers Fits Conveyor Systems:
Conveyor Systems systems in Material Handling typically involve:
- Sensors: Photoelectric sensors for product detection and zone occupancy, Proximity sensors for metal product detection, Encoders for speed feedback and position tracking
- Actuators: AC motors with VFDs for variable speed control, Motor starters for fixed-speed sections, Pneumatic diverters and pushers for sorting
- Complexity: Beginner to Intermediate with challenges including Maintaining product tracking through merges and diverters
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 Conveyor Systems
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 Conveyor Systems using Unitronics VisiLogic / UniLogic.
Implementing Conveyor Systems with Timers
Conveyor control systems manage the movement of materials through manufacturing and distribution facilities. PLCs coordinate multiple conveyor sections, handle product tracking, manage zones and accumulation, and interface with other automated equipment.
This walkthrough demonstrates practical implementation using Unitronics VisiLogic / UniLogic and Timers programming.
System Requirements:
A typical Conveyor Systems implementation includes:
Input Devices (Sensors):
1. Photoelectric sensors for product detection and zone occupancy: Critical for monitoring system state
2. Proximity sensors for metal product detection: Critical for monitoring system state
3. Encoders for speed feedback and position tracking: Critical for monitoring system state
4. Barcode readers and RFID scanners for product identification: Critical for monitoring system state
5. Weight scales for product verification: Critical for monitoring system state
Output Devices (Actuators):
1. AC motors with VFDs for variable speed control: Primary control output
2. Motor starters for fixed-speed sections: Supporting control function
3. Pneumatic diverters and pushers for sorting: Supporting control function
4. Servo drives for precision positioning: Supporting control function
5. Brake modules for controlled stops: Supporting control function
Control Equipment:
- Belt conveyors with motor-driven pulleys
- Roller conveyors (powered and gravity)
- Modular plastic belt conveyors
- Accumulation conveyors (zero-pressure, minimum-pressure)
Control Strategies for Conveyor Systems:
1. Primary Control: Automated material handling using conveyor belts with PLC control for sorting, routing, and tracking products.
2. Safety Interlocks: Preventing Product tracking
3. Error Recovery: Handling Speed synchronization
Implementation Steps:
Step 1: Map conveyor layout with all zones, sensors, and motor locations
In VisiLogic / UniLogic, map conveyor layout with all zones, sensors, and motor locations.
Step 2: Define product types, sizes, weights, and handling requirements
In VisiLogic / UniLogic, define product types, sizes, weights, and handling requirements.
Step 3: Create tracking data structure with product ID, location, and destination
In VisiLogic / UniLogic, create tracking data structure with product id, location, and destination.
Step 4: Implement zone control logic with proper handshaking between zones
In VisiLogic / UniLogic, implement zone control logic with proper handshaking between zones.
Step 5: Add product tracking using sensor events and encoder feedback
In VisiLogic / UniLogic, add product tracking using sensor events and encoder feedback.
Step 6: Program diverter/sorter logic based on product routing data
In VisiLogic / UniLogic, program diverter/sorter logic based on product routing data.
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. Maintaining product tracking through merges and diverters
- Solution: Timers addresses this through Simple to implement.
2. Handling products of varying sizes and weights
- Solution: Timers addresses this through Highly reliable.
3. Preventing jams at transitions and merge points
- Solution: Timers addresses this through Essential for most applications.
4. Coordinating speeds between connected conveyors
- Solution: Timers addresses this through Easy to troubleshoot.
Safety Considerations:
- E-stop functionality with proper zone isolation
- Pull-cord emergency stops along conveyor length
- Guard interlocking at all pinch points
- Speed monitoring to prevent runaway conditions
- Light curtains at operator access points
Performance Metrics:
- Scan Time: Optimize for 5 inputs and 5 outputs
- Memory Usage: Efficient data structures for Jazz 2 capabilities
- Response Time: Meeting Material Handling requirements for Conveyor Systems
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 1-3 weeks development timeline while maintaining code quality.
Unitronics Timers Example for Conveyor Systems
Complete working example demonstrating Timers implementation for Conveyor Systems using Unitronics VisiLogic / UniLogic. Follows Unitronics naming conventions. Tested on Jazz 2 hardware.
// Unitronics VisiLogic / UniLogic - Conveyor Systems Control
// Timers Implementation for Material Handling
// Unitronics projects use IDE-managed tag names rather than ra
// ============================================
// Variable Declarations
// ============================================
VAR
bEnable : BOOL := FALSE;
bEmergencyStop : BOOL := FALSE;
rPhotoelectricsensors : REAL;
rACDCmotors : REAL;
END_VAR
// ============================================
// Input Conditioning - Photoelectric sensors for product detection and zone occupancy
// ============================================
// Standard input processing
IF rPhotoelectricsensors > 0.0 THEN
bEnable := TRUE;
END_IF;
// ============================================
// Safety Interlock - E-stop functionality with proper zone isolation
// ============================================
IF bEmergencyStop THEN
rACDCmotors := 0.0;
bEnable := FALSE;
END_IF;
// ============================================
// Main Conveyor Systems Control Logic
// ============================================
IF bEnable AND NOT bEmergencyStop THEN
// Conveyor control systems manage the movement of materials th
rACDCmotors := rPhotoelectricsensors * 1.0;
// Process monitoring
// Add specific control logic here
ELSE
rACDCmotors := 0.0;
END_IF;Code Explanation:
- 1.Timers structure optimized for Conveyor Systems in Material Handling applications
- 2.Input conditioning handles Photoelectric sensors for product detection and zone occupancy signals
- 3.Safety interlock ensures E-stop functionality with proper zone isolation always takes priority
- 4.Main control implements Conveyor control systems manage the move
- 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
- ✓Conveyor Systems: Use rising edge detection for sensor events, not level
- ✓Conveyor Systems: Implement proper debouncing for mechanical sensors
- ✓Conveyor Systems: Add gap checking before merges to prevent collisions
- ✓Debug with VisiLogic / UniLogic: Use the built-in simulator to reproduce issues before hardware visit
- ✓Safety: E-stop functionality with proper zone isolation
- ✓Use VisiLogic / UniLogic simulation tools to test Conveyor Systems 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
- ⚠Conveyor Systems: Maintaining product tracking through merges and diverters
- ⚠Conveyor Systems: Handling products of varying sizes and weights
- ⚠Neglecting to validate Photoelectric sensors for product detection and zone occupancy leads to control errors
- ⚠Insufficient comments make Timers programs unmaintainable over time
Related Certifications
Mastering Timers for Conveyor Systems applications using Unitronics VisiLogic / UniLogic requires understanding both the platform's capabilities and the specific demands of Material Handling. This guide has provided comprehensive coverage of implementation strategies, working code examples, best practices, and common pitfalls to help you succeed with beginner to intermediate Conveyor Systems 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 Material Handling applications where Conveyor Systems 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 Conveyor Systems systems that meet Material Handling 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 Material Handling applications
3. Hands-on Practice: Build Conveyor Systems 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 1-3 weeks typical timeline for Conveyor Systems projects will decrease as you gain experience with these patterns and techniques. Remember: Use rising edge detection for sensor events, not level
For further learning, explore related topics including Alarm delays, Warehouse distribution, and Unitronics platform-specific features for Conveyor Systems optimization.