DC circuits are relatively easy to analyze, due to current flowing in one direction, with resistance being the main element of the circuit. AC circuits, on the other hand, are more complex, since voltage and current alternate direction with a given frequency. Whereas DC circuits have resistance, AC circuits often have resistance and another property, known […]
What are drive isolation transformers and how do the differ from line reactors?
A variable frequency drive alters the speed of an AC induction motor by rectifying incoming AC power to DC, storing the DC power in a bus, and then converting the DC power back to AC at the voltage and frequency required to meet the load demands. Although this matching of the motor speed to the […]
Without micromotors global logistics would be lost
Always more, always faster, always farther — everything needs to arrive at the right time at the right place. The global goods cycle keeps the economy running and presents challenges for everyone involved. Its function relies on extensive automation within the logistics chain, which would be almost impossible without an armada of high-performance micromotors. These motors often […]
What are linear springs and how do they work?
Springs that follow Hooke’s Law are often referred to as “linear springs” because they have a linear relationship between load and deflection. A linear spring has the same diameter along its entire length, and this uniform diameter gives it a constant spring rate. In other words, the spring rate doesn’t change regardless of the load acting on […]
What are vibration criteria and VC curves?
Precision manufacturing and testing processes are highly sensitive to vibrations, which often result from both internal sources such as foot traffic, fans, and pumps, and external ambient sources such as outside traffic, construction, and other nearby industrial activities. To address these concerns, a set of “generic” vibration criteria was created in the 1980s by Eric Ungar […]
What is MQTT and when is it used in motion applications?
Message queuing telemetry transport — commonly referred to as MQTT — is a machine-to-machine (M2M) messaging protocol that is extremely well-suited for devices that have low or unreliable network bandwidth. Although it was originally developed in the late 1990s for the oil and gas industry to address equipment in remote locations, MQTT has been an […]
What are power factor correction capacitors?
The measure of how efficiently a piece of equipment or facility uses power to produce work is known as its power factor. Although resistive loads, such as heating and lighting, have a high power factor, inductive loads, including AC induction motors, don’t use all of their supplied power to produce useful work, so their power […]
What is flux braking and how does it differ from regenerative braking?
AC induction motors are used to drive loads such as fans, pumps, lifts, and conveyors. But in some applications, the motor is also used as a brake to stop the load, reverse its direction, or hold the load and prevent it from moving. And while there are several methods of braking for AC motors, if […]
What role does Linux play in motion control systems?
Operating systems manage the communication between hardware and software in devices such as servers, computers, mobile phones, and embedded systems. Most personal computers and laptops use either Microsoft’s Windows operating system or Apple’s macOS, and mobile devices such as phones and tablets primarily use Google’s Android operating system or Apple’s iOS. In the industrial world, […]
What is a gated index pulse for incremental encoders?
Incremental encoders typically use two square-wave signals in quadrature (out of phase by 90 degrees) to track position and direction of motion. But because they only track incremental position (not absolute position) they’re not able to determine the true position of the motor and connected equipment after a shut-down or power loss. So most incremental […]
What do bit rate, baud, and cycle time mean in industrial networks?
For industrial networks, two of the most important performance factors are determinism and speed. In other words, industrial networks must be able to deliver data in a specified, predictable period of time, and they need to do so as quickly as possible. When describing network speed, three specifications are typically used: bit rate, baud, and cycle […]
What is Ecolab certification for automation components?
In applications that involve wet or humid environments — especially those in the food and beverage industry — a component’s IP (International Protection) rating for ingress of dust and water is an important factor in its selection. But even if a component is rated as dust-proof and protected against the forceful water jets used during washdown […]
What are Hiperface and Hiperface DSL?
Position feedback is core to any servo application, and most rotary servo motors employ an integrated feedback device with a physical link back to the servo drive, allowing the drive to read the motor’s position and correct any errors between the commanded and actual positions. Two interfaces that facilitate the communication between the motor feedback […]
What are RAMI 4.0 and asset administration shells in the context of Industry 4.0?
Industry 4.0 — the intelligent networking of machines and processes for industry with the help of information and communication technology — was initiated by the German government in 2011 (referred to in the German language as Industrie 4.0). Since that time, the principles and technologies behind Industry 4.0 have been adopted to varying degrees by manufacturers […]
What is OPC UA and how does it compare with Industrial Ethernet?
In manufacturing processes and plants, multiple Industrial Ethernet protocols — such as EtherNet/IP, PROFINET, or EtherCAT — are used across different networks to meet specific topology requirements, communication speeds, or latency guarantees. And although these communication protocols are open, they’re often incompatible, resulting in fragmented networks that can’t “speak” to each other. OPC UA (Open […]
What is time-sensitive networking (TSN)?
Most Industrial Ethernet networks can provide hard real-time communication for multi-axis, synchronized motion control. But each one uses its own methods for time synchronization and data transmission to guarantee cycle times, latency, and jitter, making these networks incompatible with one another. Time-sensitive networking (TSN) sets out to solve the network compatibility problem by providing standard […]
What’s the difference between torque mode and velocity mode in servo control?
Servo systems are used when the application calls for precise control of position, velocity, or torque — or a combination of the three. Depending on the parameter being controlled, the servo system can be operated in torque mode, velocity mode, or position mode. Each mode requires control loops that allow the servo drive and controller […]
What is direct torque control (DTC) for AC induction motors?
Variable frequency drives control AC induction motors through one of several control schemes. Scalar control (also referred to as V/Hz or V/f control) varies both the voltage and frequency of power supplied to the motor to maintain a fixed ratio between the two. This keeps the strength of the magnetic field at a constant level […]
What is isochronous real-time (IRT) data exchange?
Real-time industrial communication protocols are those in which data exchange takes place within a specified amount of time — typically less than 10 ms. But “real-time” systems can be “soft” real-time or “hard” real-time, depending on how rigidly deadlines are enforced. In a soft real-time system, occasional violations of the cycle time, or deadline, for a […]
What are explicit and implicit messaging in EtherNet/IP?
EtherNet/IP, which is the implementation of the Common Industrial Protocol (CIP) over standard Ethernet, uses two types of messaging between devices: explicit messaging for data that is purely informational, and implicit messaging for time-critical data. All four industrial networks that use CIP at the application layer — EtherNet/IP, DeviceNet, ControlNet, and CompoNet — support explicit […]
What is the Common Industrial Protocol (CIP)?
In a recent post, we explained the seven layers of the OSI (Open Systems Interconnection) protocol, including the top, or application, layer, which manages the interaction between programs or applications and the network. One example of a specialized application layer is the Common Industrial Protocol. Also referred to as CIP, the Common Industrial Protocol was […]
What is the application layer in an industrial network?
Think of all the tasks that take place behind the scenes when you interact with a program or application — such as an internet browser or email client — on a computer network. For example, the data being exchanged must be disassembled into packets, which are then transmitted across the network and reassembled at the […]
What are rotate and transfer modules for conveyors?
Pallet conveyors — conveyors that move products on individual carriers, or pallets — offer significant flexibility for assembly, automation, and inspection processes, with the ability to move products asynchronously in virtually any configuration imaginable, including curves, turns, and small elevation changes. And beyond these basic movements, special modules for pallet conveyors can transfer products horizontally […]
AS-Interface: What is it and when is it used?
Sensors and actuators have traditionally been connected to PLCs or other controllers via discrete wires and cable harnesses. But the introduction of actuator-sensor interface, also known as AS-Interface, or AS-I, in the 1990’s offered users and integrators a reliable, cost-effective replacement for the bulky, time-consuming method of parallel wiring. A new version of actuator-sensor interface, […]
Types of industrial springs: compression, extension, and torsion
Typically mounted deep inside an assembly of moving parts, industrial springs often go unnoticed, despite their importance to motion control and industrial equipment. In fact, they’re found in everything from door closing mechanisms on machine tools to mechanical seals in rotary unions. While springs are readily available in custom designs and variations, there are three primary types […]