Industrial motion control applications require precision, reliability, and flexibility. Nonvolatile-memory-based industrial controllers (NVICs) offer key advantages over traditional volatile memory-based controllers for motion control. This article examines the benefits of using NVICs for industrial motion control applications.
A key benefit of NVICs is increased reliability compared to traditional volatile memory controllers. Volatile memory requires a constant power source to retain data. If power is lost, all position data and configuration parameters stored in volatile memory are lost. This can lead to problems with precision and accuracy when the system powers back up.
NVICs use nonvolatile flash memory to store position data, configuration parameters, and application code. This data is retained even during power loss. When power returns, the NVIC can quickly resume normal operation without relearning position values or requiring reconfiguration. This improves overall system reliability and accuracy.
Precision Motion Control
Precision motion control requires accurate tracking of position and velocity. Traditional controllers sample position feedback at fixed intervals to perform closed-loop control. Between these sampling points, the actual motor position must be estimated based on the previous sample. Faster sampling rates improve precision but require greater processing power and memory.
NVICs can sample feedback and update motion parameters at much higher frequencies, up to 10X that of a traditional controller. This enables more precise real-time control of position, velocity, acceleration, and other motion parameters. Combining high-speed sampling with advanced control techniques like model predictive control further improves precision.
Adaptive Tuning for Optimal Performance
Tuning closed-loop motion systems properly for desired responses can be challenging. NVICs simplify tuning through auto-tuning and adaptive control algorithms. These advanced algorithms monitor key motion parameters in real-time and automatically adjust controller gains and filter coefficients for optimal system performance.
Auto-tuning occurs during initialcommissioning and whenever changes are detected in the mechanical load, removing the need for manual tuning. Adaptive tuning continually optimizes responses to varying operating conditions during normal operation. This ensures the highest performance and responsiveness at all times.
Advanced Programming and Customization
NVICs utilize more powerful processors than traditional industrial controllers. This allows them to run complex algorithms and provides benefits such as higher-order filtering, model predictive control, synchronous multi-axis coordination, and custom user routines. Programming languages like C/C++, .NET, and IEC 61131-3 are supported for coding custom control sequences.
Nonvolatile memory provides significant space for user programs, with memory capacities ranging from hundreds of KB up to MB. Larger programs enable developers to customize and optimize control for their specific application. NVICs also integrate readily with open industrial Ethernet networks and provide connectivity to HMIs, sensors, drives, and other automation components.
Simplified Commissioning and Maintenance
Commissioning complex motion systems can be very time consuming with traditional controllers. NVICs streamline and simplify startup procedures through GUI-based configuration tools. Rather than adjusting potentiometers and switches on the controller, all tuning parameters, I/O setups, control loop gains and other settings are configured graphically on a PC or in the HMI.
Troubleshooting and diagnostics are also improved through real-time data monitoring and logging functions. Maintenance personnel can quickly identify issues, for example tracking down any mechanical resonances or oscillations that may require system tuning. Parameter changes, firmware updates, and new program modules can be downloaded over the network, reducing maintenance costs.
Integrated Safety Features
Implementing safety functions like e-stop, safe torque off, and safe motion on traditional systems requires additional safety controller hardware. NVICs allow control, motion, and safety functions to be integrated into a single controller. Common industrial safety protocols like STO, SS1, SLS, SSM, and SBC are embedded directly in the NVIC, eliminating extra hardware.
Built-in safety functions reduce wiring and commissioning time. Integrated control and safety also enables advanced modes like safe speed monitoring, safe brake control, and safe linked motions. Overall, embedded safety capabilities in NVICs decreases cost and complexity compared to traditional distributed safety architectures.
High-Speed Synchronized Multi-Axis Coordination
Many motion applications require precise coordination between multiple axes and mechanisms. This includes applications like electronic camming, flying shears, registration control, and robotics. Performing high-speed multi-axis synchronization requires very short sample and update times.
The high-speed processing capabilities of NVICs allows them to coordinate synchronous motion across multiple axes simultaneously. Complex cam profiles, electronic gearing ratios, and motion profiles can be updated in a synchronized manner every few hundred microseconds. This enables scalable coordinated motion with very short update frequencies not practically achievable with traditional controllers.
Faster Time to Market for Machine Builders
For original equipment manufacturers (OEMs), reducing time to market for new machines is critical. NVICs allow machine builders to quickly prototype and integrate new motion control designs without requiring PLCs or external safety modules.
PC-based configuration software enables rapid virtual commissioning of machines before physical hardware is complete. Support for C/C++, .NET and IEC 61131-3 programming provides flexibility for machine builders to use their desired development environment. These capabilities allow OEMs to get new motion-centric machine designs to market faster.
Extreme Environment Operation
Industrial motion control applications often must operate reliably in harsh, extreme environments like high/low temperatures, high shock/vibration levels, humidity, and airborne contaminants. NVIC components are designed specifically for operation in extreme industrial environments.
Critical components like processors and memory chips are soldered directly to circuit boards rather than using sockets susceptible to vibration issues. Conformal coating protects against humidity and airborne contamination. Operation up to 70°C or higher is standard, with some NVICs rated for -40 to 85°C. Meeting these extreme environmental requirements is critical for reliable motion control.
Functional Safety Certification
Safety is a critical consideration for industrial motion control. Traditional controllers provide basic unsafe stop functions, but lack advanced integrated safety capabilities. NVICs incorporate safety functions up to SIL 3 as per IEC 61508, the highest level for single components.
Certification according to standards like IEC 61800-5-2 demonstrates compliance for safe motion functions. Documented failure rates and safety parameters like PFH (probability of dangerous failure per hour) are provided. Integrated safety without external modules reduces the number of safety components and simplifies validation. These certifications provide independent proof of suitability for functional safety applications.
High-Speed EtherCAT Communication
Many motion systems utilize industrial Ethernet for communication between controllers, drives, and other components. EtherCAT is a popular Ethernet-based protocol for motion control applications due to its high speed and synchronization capabilities.
NVICs provide EtherCAT slave connectivity allowing very high-speed communication with rates up to 1 millisecond. This allows tightly synchronized control across multiple nodes. Fast transfer of setpoints and telemetry data improves real-time control and coordination. Support for EtherCAT features like distributed clocks enhance synchronization. EtherCAT connectivity is essential for high-performance motion control systems.
Advanced Connectivity Options
In addition to EtherCAT networking, NVICs offer connectivity to a wide range of industrial networks and fieldbuses. These include common options like Ethernet/IP, Profinet, Sercos, Modbus TCP, Powerlink, CANopen, and more. Highly flexible connectivity integration with established communication protocols simplifies interoperability.
NVICs also provide connectivity to a wide range of digital and analog I/O including encoders, sensors, drives, contactors, operator interfaces, and more. Support is provided for interfacing to both traditional and emerging I/O technologies. This comprehensive connectivity enables seamless integration into diverse industrial control systems.
Software Tools for Simplified Commissioning
One challenge with traditional motion controllers is the complexity of initial configuration and commissioning. NVICs include GUI-based software tools to simplify and speed up the commissioning process. Rather than adjusting hardware potentiometers and switches, the entire configuration and tuning process is done through an intuitive software interface.
Graphical tools provide automated drive tuning, control loop configuration, I/O setup, cam definition, gearing, and more. Debugging capabilities like trace and snapshots allow diagnosing issues through a software interface. User-friendly software tools dramatically reduce the learning curve and speed up initial deployment of NVIC-based motion systems.
Built-in Hardware-Based Safety Features
Industrial motion systems require multiple safety functions like emergency stop, overtravel limits, and safe torque off. Implementing these functions traditionally requires additional hardware components and extensive wiring. NVICs reduce cost and complexity by incorporating essential safety capabilities directly in hardware.
Functions like STO, SS1, SLS, SSM, etc. are built into the NVIC chipset and can be easily configured through software. This eliminates the need for separate safety PLCs or safety relay modules. The hardware integration provides a high degree of reliability and diagnostic coverage. Costs are reduced by minimizing additional safety components and associated wiring.
Highly Scalable Multi-Axis Motion Networks
Demand continues to grow for motion control systems with large numbers of coordinated axes. While traditional controllers can typically only synchronize a few axes, NVICs provide motion networking capabilities to coordinate very high numbers of axes.
Real-time Industrial Ethernet protocols like EtherCAT allow connecting up to several hundred axes to a single motion network. NVICs acting as distributed EtherCAT drives can each control 1-4 axes. All NVIC nodes on the network are precisely synchronized to orchestrate complex multi-axis movements. This scalable motion network architecture enables machines with tens of axes or more.
Advanced Motion Programming Languages
Traditional motion controllers primarily use basic PLC ladder logic languages for programming. However, increasingly complex motion functions demand more advanced programming capabilities. NVICs support modern programming languages including instruction list, structured text, function block diagrams, C/C++, and .NET.
These languages enable object-oriented programming, reusable code modules, and highly structured programming. Debugging tools and network-wide variables are also provided. Programming in terms of motion functions rather than discrete I/O simplifies development. The flexible language options provide a customizable framework to meet diverse application requirements.
ExtensiveMotion Control I/O Support
Interfacing motion controllers with sensors, drives, contactors and actuators is essential. NVICs provide extensive support for both traditional field I/O as well as emerging interfaces like IO-Link. Options for digital, analog, temperature, and encoder feedback cover common motion control signals.
High-speed capture inputs up to 5 MHz support registration and high-speed position latching applications. Flexible signal processing includes quadrature decoding, counter modes, pulse width measurement, edge counting, and more. Breakout modules and pluggable connections simplify wiring. Robust support for motion I/O allows direct interface to sensors, drives, contactors, valves, and actuators.
Embedded Vision and Measurement
Machine vision is being increasingly integrated directly into motion systems for seamless coordination between vision inspection and motion. NVICs offer dedicated vision co-processing capabilities to run embedded vision and metrology algorithms directly on the controller.
Image sensors like CMOS cameras can connect directly to the NVIC for real-time vision processing. Measurement functions like pixel counting, edge detection, shape matching, and more run inline with the motion control loop. This avoids external processing hardware and simplifies integrating precise visual servoing and measurements with motion.
High-Speed Pulse Train Outputs
Many motion applications like electronic gearing require high-frequency pulse train outputs to digital drives for precise speed or position control. Generating high resolution pulses up to 1 MHz traditionally requires external hardware like a rack of VFD cards.
NVICs incorporate dedicated motion processing chips capable of producing pulse & direction or quadrature encoder outputs up to 1 MHz. Electronic gearing, cam switching, and feed-forward profiles are all easily implemented without external modules. High-speed integrated pulse trains simplify system architecture for precision motion applications.
Summary of Benefits
NVICs provide a wide range of benefits for industrial motion control applications, including:
- Increased reliability through nonvolatile flash memory for position data.
- More precision motion from higher speed feedback sampling and advanced control algorithms.
- Adaptive tuning algorithms that optimize responses automatically.
- Advanced customization through open programming languages and large nonvolatile storage.
- Simplified commissioning and maintenance via GUI-based software tools.
- Integrated safety protocols to reduce hardware requirements.
- High-speed multi-axis coordination via deterministic Ethernet networks.
- Faster time to market for machine builders through rapid virtual commissioning tools.
- Extreme environment operation with industrial temperature ratings and vibration resistance.
- Functional safety certifications for suitability in SIL 2 and SIL 3 applications.
- EtherCAT connectivity for high-speed communication and synchronization.
- Comprehensive connectivity options for industrial networks and field devices.
- User-friendly software tools to ease initial configuration steps.
- Hardware integration of safety functions for reliability and reduced wiring.
- Highly scalable multi-axis networks using distributed motion control architecture.
- Advanced motion programming languages for maximizing performance.
- Extensive support for digital, analog, temperature, and encoder I/O.
- Built-in vision and metrology for embedded measurements.
- High-speed pulse trains for electronic gearing and precision control.
NVICs provide an integrated platform that combines high performance motion, flexible programming, and embedded safety for reliable and responsive automation. The benefits highlighted in this article demonstrate the key advantages NVICs offer over previous-generation motion controllers.