Networking + IoT - Motion Control Tips

New inductive positioning system from Pepperl+Fuchs offers precise position detection

October 11, 2018 By Miles Budimir Leave a Comment

Pepperl+Fuchs’ new PMI F90 inductive positioning system works with a unique, patented multi-coil system. The absolute position of the actuator is precisely detected from the measuring signals of a single coil. In addition to sending the analog position signal, switch points can also be defined. The sensor can detect two actuators as well as the distance between them, meaning that dynamic positioning tasks can be completed with the smallest amount of measuring technology.

PMI inductive positioning technology combines the ruggedness of an inductive proximity sensor with the precision of a position measurement and angular positioning system. The patented technology ensures highly accurate measurements, and the ability to use simple steel actuators is designed to maximize the flexibility of applications.

The device’s IO-Link interface enables continuous data flow, making it suitable for Industry 4.0 applications. Event logs, error messages, signal quality data, device status, and operating hours can all be read directly via an IO-Link master.

Certified versions of the PMI product family allow the system to be used in ATEX Zone 2/22 (3G nA, 3D tc) hazardous locations. The compact design allows these sensors to be installed in even the tightest of spaces, while the rugged metal housing protects them from external influences. IP67 protection and a temperature rating of -25 °C to +85 °C ensure reliable positioning in outdoor environments.

The advantages of the inductive measuring principle apply to all devices: noncontact, low-wear and maintenance-free, dirt-resistant, and resistant to interference. All steel components or objects can generally be used as actuators since the inductive system is not reliant on a magnetic actuator.

For more information, visit www.pepperl-fuchs.com/usa/en/.

New functions in B&R SafeDESIGNER 3.1 include expanded numeric ranges for functions

October 5, 2018 By Lisa Eitel Leave a Comment

The latest version of B&R’s SafeDESIGNER tool now makes it possible to process and compare safe INT and DINT signals in addition to linking them mathematically using basic arithmetic operations. Safety-oriented function blocks are also available for converting INT and DINT values in either direction. This expansion now rounds off the full range of numeric functions for the Automation Studio 4 development and configuration tool.

Safety applications increasingly need numeric functions to manage values for pressure, temperature and speed. Since its introduction in 2008, SafeDESIGNER has provided support for safe INT data types and associated arithmetic operations and comparison functions. This range of functions has been continuously expanded ever since.

Monitoring synchronous operation with B&R software

Users of Smart Safe Reaction technology from B&R can now process safety-related speed and position values and use them to initiate safe machine states. These functions are suitable for cases where requirements go above and beyond the possibilities provided by prepackaged SafeMOTION functions. Possible scenarios include integrating additional safe rotary encoders in a safety application or monitoring several power transmission systems for synchronism. In process control applications, SafeDESIGNER has become a widely used tool perfectly suited for the safe processing of pressure, temperature and flow signals.

B&R is a privately owned company with headquarters in Austria and offices all around the world. As a global leader in industrial automation, B&R combines state-of-the-art technology with advanced engineering to provide customers in virtually every industry with complete solutions for machine and process automation, motion control, HMI and integrated safety technology. With industrial fieldbus communication standards like POWERLINK and openSAFETY as well as the powerful Automation Studio software development environment, B&R is constantly redefining the future of automation engineering. The innovative spirit that keeps B&R at the forefront of industrial automation is driven by a commitment to simplifying processes and exceeding customer expectations. For more information, visit www.br-automation.com.

Festo Industry 4.0-Enabled technology and engineering productivity tools — and electric and pneumatic automation systems — at IMTS 2018

September 11, 2018 By Lisa Eitel Leave a Comment

At IMTS this year, Festo is showing the Motion Terminal, a modular Industry 4.0 device – a single unit capable of replacing 50 different components through the download of various combinations of cloud-based apps. The Festo IMTS Booth is 134357 — in the East Building Level 3.

The Motion Terminal seamlessly integrates computational algorithms and physical components. This new cyber-physical system enables the Industry 4.0 advantages of small lot size manufacturing, adaptability to shorter product life cycles, scalability, resiliency, energy conservation, cloud-based predictive analytics, and more.

At IMTS, Festo also features the latest version of the Handling Guide Online and the new Festo Motion Control Package. These engineering productivity tools slash the costs of Cartesian robot engineering, assembly, and programming as well as shorten time to market for new machines.

Festo showcases the company’s expanded offering of electric automation devices, including the new low-cost linear axes ELGC and mini slide EGSC. These new electric actuators offer an optimal ratio between installation space and working space. Additional IMTS highlights from Festo include:

A portfolio of IO-Link solutions
A host of mechanical grippers
Electric and pneumatic safety systems that lower overall risk of equipment damage and worker injury
A flexible loading system for end-of-line packaging and other applications
The new CPX-E compact, low-cost controller for handling systems.

Festo demonstrates how the company’s global Stars of Automation program lowers downtime and reduces overhead through guaranteed 24-hour shipment of core Festo products. For more information, visit www.festo.us.

What are slip rings and why do some motors use them?

August 21, 2018 By Danielle Collins Leave a Comment

Slip rings — also referred to as rotary electrical joints, electric swivels, and collector rings — are devices that can transmit power, electrical signals, or data between a stationary component and a rotating component. The design of a slip ring will depend on its application — transmitting data, for example, requires a slip ring with higher bandwidth and better EMI (electromagnetic interference) mitigation than one that transmits power — but the basic components are a rotating ring and stationary brushes.

A complete slip ring assembly includes end caps, bearings, and other structural features. But the basic components of a slip ring are the ring and the brushes.
Image credit: Moog Inc.

If the rotation of one component involves a fixed number of revolutions, it may be possible to use spools with sufficient cable length and rotating speed to allow for the required revolutions, although cable management in this setup can be quite complex. But if one component rotates continuously, using cables to transmit signals between the rotating and stationary components isn’t practical or reliable in many cases.

Slip rings in AC motors

Image credit: brighthubengineering.com

In a version of the AC induction motor referred to as a wound rotor motor, slip rings are used not for transferring power, but for inserting resistance into the rotor windings. A wound rotor motor uses three slip rings — typically made of copper or a copper alloy — mounted to (but insulated from) the motor shaft. Each slip ring is connected to one of the three phases of rotor windings. The slip ring brushes, made of graphite, are connected to a resistive device, such as a rheostat. As the slip rings turn with the rotor, the brushes maintain constant contact with the rings and transfer the resistance to the rotor windings.

Slip rings on a wound rotor AC motor. Once the motor reaches operating speed, the brushes are lifted via the springs and the slip rings are short-circuited via the sliding contact bar.
Image credit: Wikipedia

Adding resistance to the rotor windings brings the rotor current more in-phase with the stator current. (Recall that wound rotor motors are a type of asynchronous motor, in which the rotor and stator electrical fields rotate at different speeds) The result is higher torque production with relatively low current. The slip rings are only used at start-up, however, due to their lower efficiency and drop-off of torque at full running speed. As the motor reaches its operating speed, the slip rings are shorted out and the brushes lose contact, so the motor then acts like a standard AC induction (aka “squirrel cage”) motor.

The slip rings in a wound rotor motor form a secondary, external circuit. Inserting resistance to this circuit allows the motor to produce very high torque at start-up, which is necessary for moving loads with high inertia.

Slip ring or commutator?

You may have noticed that the design and function of a slip ring sounds very similar to that of a commutator. While there are similarities between the two, there are critical distinctions between slip rings and commutators. Physically, a slip ring is a continuous ring, whereas a commutator is segmented. Functionally, slip rings provide a continuous transfer of power, signals, or data. Specifically, in AC motors, they transfer resistance to the rotor windings.

Commutators, on the other hand, are used in DC motors to reverse the polarity of current in the armature windings. The ends of each armature coil are connected to commutator bars located 180 degrees apart. As the armature spins, brushes supply current to opposing segments of the commutator and, therefore, to opposing armature coils.

Slip rings are used in virtually any application that includes a rotating base or platform, from industrial equipment such as index tables, winders, and automated welders, to wind turbines, medical imaging machines (CT, MRI), and even amusement park rides that have a turntable-style operation. Although the traditional application for slip rings was to transmit power, they can also transmit analog and digital signals from devices such as temperature sensors or strain gauges, and even data via Ethernet or other bus networks.

Feature image credit: Rotary Systems Inc.

New inclinometer for pitch, yaw, and roll feedback from Joral

July 18, 2018 By Miles Budimir Leave a Comment

Joral’s new G-force compensated inclinometer provides feedback for pitch, yaw, and roll. The new technology uses sensor fusion, which is the combining of more than one complementary sensing method. The new Joral SGAM and DGAM incline sensors take input by a gyroscope, accelerometer, and magnetometer to provide a 3-axis output for X, Y, and Z as well as new feedback for pitch, yaw, and roll.

The GAM Series sensor provides steady feedback during motion, allowing users to eliminate complex sensor networks with a single G-force compensated inclinometer. Rather than depending on encoders, string pots, laser gates, and proximity sensors to monitor the position of a ladder, fork or platform, users can place one Joral GAM Series sensor on the application to get real-time feedback for absolute control.

Joral has designed the same level strength into the GAM series as other standard Joral products. Rated with a standard environmental protection of IP67, the GAM series sensors are 100% encapsulated. Designed to eliminate the drawback of accelerometer based incline sensors, the SGAM and DGAM inclinometers are J1939 capable, and available in a convenient form factor with common connection options, including a CAN Open connection.

For more information, visit www.joralllc.com.

More details on the trend towards Ethernet-based networking protocols

July 9, 2018 By Lisa Eitel Leave a Comment

In a recent survey of industry experts, many mentioned Ethernet-based networking protocols overtaking traditional fieldbuses.

Recall that industrial communication protocols (including those based on Industrial Ethernet) are messaging systems for automated installations. Some fieldbuses are more reliable than nondeterministic Ethernet offerings, but Ethernet speeds now lead.

“Some old bus systems have data rates in the range of 1 to 20 Mbit and no real-time reaction,” said Horst Messerer, HELUKABEL data, network, and bus technology sales manager. “Certain types of manufacturing can tolerate these rates … so bus protocol won’t go away entirely — but they’re seeing reduced market share.”

In fact, industrial Ethernet-based networks now connect some 40% of industrial communication networks.

“That’s why more bus systems are being replaced with Ethernet-based equipment,” said Messerer. “The advantage of Ethernet is its faster data rate — with a minimum of 100 Mbit — which lets industrial-automation manufacturers view manufacturing and production process data in real-time. Having this kind of data quickly allows for improved reaction time to optimize processes for higher output per hour.”

Another benefit is that even though older variations such as 802.3c is slower than 802.3ab (at 1 Gbit/sec, which is called GbE) all use Cat5e cable. That makes Industrial Ethernet implementation easier. Both Cat5 and newer Cat6 cables for Ethernet work with Gigabit Ethernet, though Cat6 Ethernet cable is displacing the former.

“We’ve seen continued robust interest in both Cat5 and Cat6 flat cables,” said Rich Buchicchio of Cicoil Corp. “Our versions of these cables typically go in applications that benefit from high cable flexibility and durability to survive extreme environments better than common versions of these Ethernet cables.” The cables meet (and typically exceed) platform requirements.

Besides speed, other reasons for Ethernet’s rise include its ease of use, and ubiquitous design; multi-protocol network acceptance; familiarity thanks to commercial off-the-shelf (CotS) Ethernet; and consolidation of network-interface hardware. Plus unlike traditional device and fieldbus networks (that can have multiple physical layers) Ethernet networks run on one.

Controls and related motion hardware often dictate which fieldbus communications an installation will use.

“We continue development of integrated motors that can be powered over Ethernet (PoE),” said Eric Rice of Applied Motion Products. “Combining power and Ethernet over a single cable is an excellent example of the evolution of integration in motors, drives, and industrial Ethernet communications.”

PoE-enabled integrated motor offerings from the manufacturer include NEMA 14 and NEMA 17 frame motors.

Traditional industrial components feature Ethernet connectivity for an increasing array of functions. “Today, there are scalable I/O options for PLC control … and new hardware to communicate with remote I/O includes multi-Ethernet products to cover major Ethernet such as SERCOS, EtherCAT, PROFINET, and EtherNet/IP,” Joaquin Ocampo, product manager of motors and drives at Bosch Rexroth.

In fact, five real-time protocols — CC-Link, EtherCAT, EtherNet/IP, PROFINET, and SERCOS III capitalize on Ethernet advantages and deterministic networking.

The CC-Link protocol (supported by the CC-Link Partner Association) includes field-device, controller, and information networking and gets speeds to 10 Mbps at 100 m. Versions include CC-Link, CC-Link Safety, CC-Link/LT, and CC-Link Industrial Ethernet (IE) Control and Field. One CC-Link standard is a Seamless Message Protocol to let Ethernet-ready devices work on CC-Link IE networks. A new version of a Control and Communication System Profile (CSP+) simplifies integration of engineering tools and device profiles (in part by outlining the data necessary for setup and operation of CC-Link-compatible devices). Automation-component manufacturers primarily offer CC-Link functionality for servomotors, drives, robots, digital and analog I/O modules, and controllers including PCs and PLCs.

The Ethernet for Control Automation Technology (EtherCAT) protocol uses Ethernet and twisted-pair or coaxial cables with BNC adapters over distances to 1,000 m and optical cable beyond that. It gets Ethernet transfer rates and can control up to 65,535 nodes. Data processing through dedicated software and hardware allows deterministic communications. EtherCAT accommodates any topology and handles 1,000 I/O points in 30 μsec — capable of communicating with 100 servo axes in 100 μsec. Axes get values and control data and report position and status. A simple version of an IEEE 1588 distributed clock technique synchronizes axes with less than 1 μsec of jitter.

Shown here is a maxon motor EPOS04 Compact 50/8 EtherCAT smart drive-controller for programmable positioning.

Ethernet/IP is an industrial application-layer protocol for communication between industrial controls and I/O. It uses standard IEEE 802.3 TCP/IP and communications; Ethernet hardware pairs with TCP and UDP ports. Certain permutations enable synchronized and deterministic multi-axis motion control.

In fact, this and other industrial-Ethernet standards drive many product-development decisions that Applied Motion Products makes. “This year we enhanced our support for EtherNet/IP networks by introducing a set of improved Add-On Instructions for Rockwell’s RSLogix 5000 software,” said Rice. “We also introduced a new family of cost-effective motor drives for EtherCAT networks … and have begun development on drives and integrated motors for use on PROFINET networks,” he added.

Serial Real-time Communications System (SERCOS) is an open protocol for serial communication of closed-loop real-time data — over Ethernet cable for SERCOS III. Specifically for motion controllers, drives, actuators, sensors, I/O, the IEC-standard protocol closes servo loops in the drive to reduce motion-controller burden (and synchronize more motion axes than otherwise possible). Such closing of servo loops also avoids delays between motion controls and drives.

SERCOS III gets deterministic bidirectional real-time motion and control. It also enables higher-level I/O and transmission of conventional protocols over one Ethernet network in parallel with SERCOS real-time communication — with cycle times to 31.25 μsec.

PROFINET is from the same organization from the same organization that gave the motion industry PROFIBUS (PROFIBUS & PROFINET Intl. or PI) PROFINET use of Ethernet means larger messages, better bandwidth, and theoretically unlimited address space … as well as avoidance of network collisions. Deterministic communications are possible through real-time and isochronous real-time (IRT) operation. The latter gets update times down to 250 µsec, while PROFINET IRT gets them down to 31.25 µsec for synchronizing networked components.

Of course, industry-specific communication buses endure and even grow, as connectivity imparts design sophistication even to turnkey operation.

“Products with integrated industrial communications protocols simplify operation,” said Laura May of Thomson Industries. “For example, integration of J1939 CAN bus communications — most commonly used in mobile off-highway markets — means a system can programmed to let each of its actuators run with real-time awareness of speed and position of other actuators — enabling self-adjustment and deploying multiple actuators to handle heavy loads,” May added.

She added the manufacturer has work in progress to better support protocols commonly used in plant-floor automation.

Of course, an ever-growing (and cost-effective) array of gateways simplify network connections where J1939 CAN (and other buses) must interface with Ethernet. It’s common for fieldbus components to connect to Ethernet blocks for connectivity via Cat5E cable and Ethernet RJ45 connectors. Ultimately, Ethernet can even facilitate IIoT functionality to connect enterprise-level systems with machine, I/O, and device-level operations.

Ethernet-driven cloud-based IIoT along with (IEEE-802-compliant) wireless variations unify data streams for:

I/O and motion communications and controls
Safety functionality to protect equipment and personnel
Diagnostics, machine-condition monitoring, and energy management
Final product tracking and documentation of plant-operation statistics

“One of three smart Han modules available is the Mini Ethernet Switch Module,” said Mark Kojak, V.P. of product management and business development in the Americas at Harting Inc., manufacturer of interconnect components. This module incorporates a four-port Ethernet switch within the connector. The module can replace or reduce the port count in systems needing a multi-port Ethernet switch … and excels in systems that use a daisy-chaining architecture.

Case study: Slip rings use CC-Link IE for gigabit data transfer

By John Wozniak, P.E. | Manager of CC-Link Partner Association (CLPA) Americas

Manufacturer of mobile electrification and data transfer systems for industrial machinery Conductix-Wampfler now uses CC-Link IE open gigabit Ethernet (GbE) for high-performance connections in its slip rings. Traditionally used to supply continuous power and data communication to equipment on rotating assemblies, the slip rings are for new and existing machinery needing Industry 4.0 data connectivity.

Conductix-Wampfler specializes in power, signal, and data-transmission systems for container handling, tunneling, mining, and bulk material handling. Their slip rings find use on rotating arms and gantries, cranes, wind turbines, manipulators, and cable reels.

As a CLPA member, Conductix-Wampfler has technical specifications to develop compliant product … even for custom connectivity solutions that work with Ethernet up to 1Gbps.

“Our slip ring technology excels in everything from industrial machinery to theme park rides … and we see need to transfer an increasing amount of data in a secure and easily accessible manner,” said product manager at Conductix-Wampfler Matteo Mosconi. So the company joined CLPA to focus on CC-Link IE because it’s the first and only open protocol that works at 1Gbps with real-time characteristics — and the organization that supports it offered the technical support Mosconi wanted.

“Slip rings certified for CC-Link IE can transmit power … as well as data at very high transfer rates.”

Founded in 2000, CLPA is an international open-network organization with more than 3,000 members (and the leading open industrial-automation network technology in Asia) dedicated to technical development of CC-Link open automation networks. Main activities include the development of CC-Link IE and CC-Link technical specifications; conducting conformance tests and development support. CC-Link IE is an open GbE solution for Industry 4.0 automation with unmatched bandwidth.

CC-Link Partner Association (CLPA) member Conductix-Wampfler used CC-Link IE open GbE technical specifications to develop compliant slip rings.

Safety brakes and intelligent monitoring from mayr for brake technology 4.0

June 28, 2018 By Lisa Eitel Leave a Comment

Safety brakes by mayr power transmission are equipped for the challenges of the Industry 4.0. The coordinated system guarantees the highest level of operational and functional safety …

… and increases the productivity of machines and systems through predictive error detection and maintenance.

Brake technology 4.0 stands for intelligent monitoring modules; modules such as the ROBA-brake-checker and the ROBA -torqcontrol monitor safety brakes easily and quickly or facilitate the even and smooth deceleration of machines and devices.

mayr power transmission as the leading manufacturer is already offering reliable safety brakes, which are equipped for the challenges of the forth industrial revolution.

Permanent brake monitoring and predictive maintenance

The ROBA -brake-checker module operates without sensors. Instead, it analyzes current and voltage and recognizes the movement of the armature disk. So it knows the condition of the brake. In addition to the switching condition, the module can also deduce the temperature, wear and tension path or tensile force reserve — in other words, whether the magnet still has sufficient force to attract the armature disk.

On reaching the tensile force reserve, the ROBA-brake-checker emits a warning signal, early enough so that a defined operating time of the brake is still possible. Within this time, the machine operator can undertake specific maintenance in coordination with their work process – maintenance with foresight, so to speak. The ROBA -brake-checker is now available in a design for AC voltage. In addition, another version of the module will also in future take on the supply of the brake, and as a result, replace the rectifier. Switching condition monitoring and brake control are therefore combined in one device.

Braking movements gently and in a controlled manner

For applications, which need braking torque control in addition to status monitoring, mayr power transmissions provides the braking torque control module ROBA -torqcontrol. It shares the features of the ROBA -brake-checker and can also change the level of the braking torque in operation through purposeful influencing of current and voltage. As a result, devices and machines can be evenly and gently decelerated. The ROBA -torqcontrol module permits the development of control loops and brakes movements intelligently – the suitable basis for its use in smart, interconnected machines.

The brake control module ROBA -SBCplus performs reliable switching time monitoring. It is type-certified by TÜV Süd and can be used up to the highest Performance Level PLe and Safety Integrity Level (SIL) 3. Image: mayr power transmission

Another module to continuously monitor the switching condition of the brakes is the safe brake control ROBA -SBCplus. In this module, mayr power transmission offers safety brakes and safe brake control in a complete package. This module has been developed in collaboration with the company Pilz, especially for applications which have to fulfil requirements for the protection of people according to standards regarding functional safety. The ROBA -SBCplus module must reliably interrupt the current in the magnetic coil when the brake is switched off. For this purpose, the module operates with wear-free electronic semi-conductors, and as a result achieves practically unlimited switching frequency and switching reliability.

Brake technology 4.0 by mayr power transmission stands for monitoring modules of the latest generation: The modules such as the ROBA-brake-checker or the ROBA-torqcontrol allow permanent brake monitoring and make the safety brakes fit for the challenges of the Industry 4.0.

This brake control module performs reliable switching time monitoring. Furthermore, an integrated plausibility check is conducted through the evaluation of the release monitoring signals. The evaluations of the switching states and the return signal therefore permit reliable error diagnostics. This permits creep errors which influence on the switching times, for example increasing wear, to be detected in due time. The reliable ROBA -SBCplus brake control unit is type-certified by TÜV Süd (Technical Inspectorate, Southern Germany) and can be used up to the highest Performance Level PLe and Safety Integrity Level (SIL) 3.

SmartCamera delivers robust vision in simple package

June 5, 2018 By Paul Heney Leave a Comment

Balluff’s newly released SmartCamera takes inspection and identification applications, in color or monochrome, to a higher level. The SmartCamera simplifies overall usability in an otherwise complex world of vision-based technology, while still delivering a robust assortment of features like flexible connectivity and intuitive on-board image processing tools. The camera, the latest in in a line of Balluff tools designed to innovate automation, combines the power of the HALCON function library with the simplicity of the BVS-Cockpit user interface.

“Minimizing time of deployment and eliminating the over-use of plant resources to integrate vision technology is critical. The wizard-based programming tools allow for efficient set up, and simple adjustments can be made on the fly,” said Balluff Marketing Manager Wolfgang Kratzenberg. “The SmartCamera is also the most connected camera available. With an on-board IO-Link master in addition to Ethernet/IP, Profinet, TCP and UDP communication, this camera can be integrated into any major control network.”

Balluff’s commitment to vision as a solution includes offering a full line of accessories required to address applications in the industrial manufacturing environment. This broad offering includes: optics, lighting, displays, mounting hardware and power supplies along with a wide range of IO-Link products which can be directly controlled by the SmartCamera.

Balluff Inc.
www.balluff.com

Teledyne DALSA to preview multi-line CMOS camera

March 30, 2018 By Paul Heney Leave a Comment

Teledyne DALSA, and Teledyne e2v, both Teledyne Technologies companies and global leaders in image sensing technology, will be co-located at The Vision Show, in booth #517 from April 10th to 12th. Teledyne DALSA will display its newest and most advanced multi-line CMOS camera while Teledyne e2v will display their new OctoPlus range of line scan cameras for OCT applications in healthcare and industrial markets. The show takes place at the Hynes Convention Center, in Boston, Massachusetts.

The Teledyne DALSA team will present a wide-array of the company’s very latest imaging technologies. In-booth demonstrations include:

• A preview of Teledyne DALSA’s newest multi-line CMOS camera, offering options for monochrome, color, and NIR imaging, with fiber optic interface to an Xtium CLHS frame grabber.
• BOA spot vision sensor, which offers simple, affordable and reliable performance for automated quality inspections
• Calibir uncooled long wave infrared cameras for thermal imaging applications, featuring shutterless operations with GigE Vision, analog and MIPI CSI-2TM interfaces
• Genie Nano cameras, feature-rich and built around industry-leading CMOS image sensors with GigE or Camera Link interface
• GEVA 4000 vison system, with over eight times the processing performance of the entry level GEVA 300, ruggedized and robust for the factory floor.

In addition to live demonstrations, show attendees will see static displays of Teledyne DALSA’s newest area cameras, including the 86-megapixel Falcon4, frame grabbers, smart cameras, and image processing software. Visit the Teledyne Imaging booth to explore this wide portfolio of technologies designed for many markets and applications.

Hot Corner Topics

Teledyne DALSA subject matter experts will present in two Hot Corner topic discussions. Hot Corner discussions are open to all show attendees.

Tuesday, April 10, 1:00 pm – 3D Imaging Technologies – Raymond Boridy will present on current 3D technologies, applications and trends

Thursday, April 12, 1:15 pm – Multi-channel line scan imaging – Mark Butler and Philip Colet will deliver a presentation focused on the possibilities of multi-channel line scan imaging

The Vision Show 2018
April 10-12, 2018
Booth #517 (See booth location)
Hynes Convention Center, Boston, Massachusetts

The Vision Show is North America’s largest display of machine vision and imaging components and systems. Registration is free.

Teledyne DALSA
www.teledynedalsa.com

How to use SPI for dc motors?

March 27, 2018 By Miles Budimir Leave a Comment

SPI (Serial Peripheral Interface) is a method of data transmission. It’s designed to transmit data between microcontrollers and peripheral devices such as sensors, memory cards, and displays, among others.

At its basic physical level, it’s a 4-wire serial interface with data rates that can vary from a few MHz to upwards of 10 MHz, and claims of even higher rates in some cases. Data transmission is from 2 to 16 bits, depending on how it is programmed.

Evaluation boards for brushless dc motor control, such as the one pictured here from Microchip, feature on-board PWM signal generation as well as an SPI interface (upper left corner, horizontal 6-pin header.) (Image via Microchip)

With regard to how SPI applies to dc motors, the motors themselves aren’t driven directly via SPI but rather by way of a motor driver. Typically, the motor driver will have an SPI port that can be connected to a microcontroller which sends control signals such as PWM signals. Or in some cases the controller may reside on the same chip where the control signals are generated. Aside from control, SPI can also be used for diagnostic purposes.

The pros from a microcontroller programming point of view are that most microcontroller families have built-in SPI communication, making it easy to connect with peripherals. Another plus is that programming via SPI is fairly simple. The protocol is fairly simple and support circuitry is not complex and is easy to implement.

On the down side, it is generally a short distance communication link. Some of the largest distances have pushed the 100 m mark. However, with longer runs more signal delay is introduced, which affects timing of signal propagation.

Still, there are many examples of controlling dc motors with simple controller chips using an SPI interface, including the Raspberry Pi, Arduino, as well as motor drives from Microchip.