In 1969, Programmable Logic Controllers (PLCs) were first introduced into manufacturing processes, and today, they are most widely used for automation and industrial process control. In an industrial setup, PLCs are used to control conveyor systems, to sequence automated devices such as robots, and to capture data and communicate information. Almost any machine function, process or production line is greatly enhanced whenever a PLC control system is used. A PLC system is modular, this allows you to mix and match different types of Output and Input devices to best suit your applications. Nevertheless, the greatest benefit of utilizing a PLC is its ability to replicate and change a given process or operation, while collecting and disseminating essential information. Typically, any PLC has a Central Processing Unit, the CPU, which contains an internal program. The program tells the PLC how to perform various functions such as Execute user defined control instructions that are contained...
Industries globally understand the importance of electric drives in ensuring efficient control of motor outputs. And with the constant developments and innovations springing up in the industrial automation field, the need for alternating current (AC) and direct current (DC) drives have continued to grow in leaps. Both AC and DC drives are indispensable to the regulation of control signals. However, there are notable differences between the two drives. This article focuses on these differences in terms of benefits, composition, operation, capability, cost, and usability. The AC Drive and its Benefits The AC drive is used to control motor speed through the conversion of direct current (DC) to alternating current (AC). This drive involves such components as an inverter unit, DC circuit, rectifier unit, etc. It has helped increase productivity and innovation in the electronics industry. AC drives operate only with motors whose speeds are controlled by switching frequency from the...
The printed circuit board (PCB) invention ushered in a radical change in electrical and electronic technology. This success has led to the continued improvement of many devices and smaller and even miniature profiles for others. It has also resulted in entirely new classes of products across almost every industry. And it isn’t easy to imagine a powered device or appliance without a PCB. As the technology has matured, two distinct methods for producing PCBs emerged. The first is surface mount technology (SMT). Because PCB components became smaller over time, SMT became the dominant technology by volume. In SMT, components are mounted directly onto the bare board surface. Instead of wires, tabs and connectors are used with solder to complete the board circuitry. Through-hole technology (THT), holes are drilled in the bare board, and wires are run through the holes to connect the components. One side of the board will have “trace holes” to mark the path of the wiring. Wires are soldered...
Servo drives are an integral part of a servo system. Working in tandem with a motor, controller, and a feedback device, servo drives receive instructions from the controller for the prescribed motion for the motor. It then sends the right amount of electrical current to enable the motor to perform the motion required. There are several types of servo drives including those that control torque as well as velocity and positioning. But torque is the most used variable in many servo systems. Because they deliver the precise required voltage and current to motors, servo drives are also called amplifiers. All variables encountered by service systems – torque, position, velocity – are part of a complex motion control system that impacts safety, efficiency, and equipment condition. So, having the right servo system components are critical. Without the right components, servo systems could overheat and shorten the lifespan of the motor. There are many OEM producers of servo drives across the...
In any automation system design: cost, functionality, space, and interoperability are always on the mind of the engineer designing the system. This is true of small control builds and complex, factory-wide control environments with numerous machines connected to the system. For many decades, PLCs have been the workhorse of such automation and control systems, providing an effective and reliable way for engineers to get the job done. But within the last decade, microcontrollers have come to the forefront of numerous applications leading many to wonder if they can be considered a more cost-effective and smaller substitute for PLCs. As the “maker” culture arose with small automation applications such as desktop 3D printers, an entire ecosystem of accessories grew with them until many have reached a comparable feature set and list of capabilities of PLCs. Why then can’t they be used in place of traditional PLCs? The answer lies in a few important distinctions between the two. Benefits of...
As smart factories, facilities and cities continue to grow, so does the need for improved visualization and functionality in Human Machine Interfaces (HMI). By bringing that visualization down to the operator and technician level at the machine level, machine state, error messaging, real-time running conditions, and other information can be graphically displayed to assist in decision-making and remediation of problems. Introduced in 2015, Allen Bradley’s PanelView Plus 7 Performance offers a broader range of features than its predecessor, the PanelView Plus 7 Standard. For system designers looking to use the PanelView 7 family in their control design, here is a comparison of the most common features of each: There is quite a difference in screens and alarms allowed in a system between the Standard and the Performance. The PanelView Plus 7 Standard allows up to 100 graphics screens within a control system. The Standard is also limited to 500 alarms. By contrast, the PanelView Plus 7...
According to ISA, automation is defined as “the technique of making an apparatus, a process, or a system operate automatically”. In a more practical sense, it is a system that operates with minimum or no human intervention at all. It has been part of the development of mankind all along however, the concept was further realized after the mass production system was finally implemented. With automation in the mass production setup, consistent and uniform outputs may be produced. Absolutely, this cannot be achieved with manual and traditional automation. Fast forward today, a control system – whether commercial or industrial scope, meets the modern automation requirements if it is programmable. With the birth of the 1st programmable controller and the enhancement in the succeeding years, most control systems are now being governed by programmable controllers. Programmable controllers can be used in both home and industrial setup. They are also the core components of automation. They...
The Allen Bradley VersaView line is distinctly different from the PanelView and Component HMI class. The VersaView line combines monitors, industrial PCs, and thin clients that work on an open architecture platform. The VersaView line also has fewer connectors and is fanless, reducing commissioning time and setup costs. By combining these industrial computers and monitors with software applications and thin client software, the entire visualization experience is enhanced. The use of thin clients provides a cost-effective solution for both standalone and complex visualization systems throughout an operation. By connecting via server to access stored applications, local hard drives are not needed. This centralized approach also helps users better ensure security than distributed hard drives that may be more susceptible to breach. The VersaView Family The VersaView line is designed for system flexibility and centralized server access to power the visualization applications. This is...
Variable Frequency Drives (VFD) and Soft Starters are electronic devices that are popularly used in a wide variety of industrial processes which require the utilization of AC motors. These devices share a common, specific purpose to which they are applied, particularly in the field of motor protection and lowering of energy consumption. But what is the difference between a VFD and a Soft Starter? Before we differentiate the difference between each of the devices, let us understand first the common industry terms used to refer to these devices. A Soft Starter is commonly termed as Soft Starter, Motor Starter, or simply starter. A VFD is popularly termed as Variable Speed Drive (VSD), Adjustable Frequency AC Drive, Adjustable Speed Drive, or simply an Inverter. Soft Starters are generally used to protect the AC motor from the stress produced by a large amount of electrical inrush when the motor is started or stopped. During start-up, high amount of inrush current is absorbed directly by...
Continuing our article series on Programmable Logic Controller selection, we’ll look next at Rockwell Automation’s line of Allen-Bradley Micro800 PLCs. These controllers are particularly well positioned to tackle basic single-machine control, offering a versatile range of form factor, expansion, and connectivity options. Despite their modest cost and size, the Micro800 series is packed with advanced features that you’d normally expect only of much larger platforms. The Micro800 (and sister MicroLogix) series sits at the micro-scale end of Allen-Bradley’s PLC offerings, just under small-scale options such as the CompactLogix series, and farther yet under large-scale solutions including the flagship ControlLogix series. These series groupings do not translate into differences in quality or reliability – these names only refer to the scale of the applications each family is designed to serve. Where a ControlLogix PLC may control an entire plant, a Micro PLC is a much better fit to...
Allen Bradley has long offered an extensive line of HMI products for any application. From standalone machines to complex control systems integrating entire operations, they provide reliable, accurate, and robust HMIs for any need. These HMIs allow operators, system designers, and technicians access to real-time machine conditions and process status by choosing the appropriately sized HMI product for the required application. Decision-makers from the shop floor level to the back office can count on accurate and highly visualized data to allow them to make the best decision for the situation. Machine Level HMIs The PanelView Plus 6 HMI was one of Allen Bradley’s earlier HMI products. It is now under “End of Life” status but is still available both surplus and refurbished. The PanelView Plus 6 is available in six screen sizes, including 7”, 10”,12.5”, and 15” (designated as the 700, 10000,1250, and 1500 respectively). The Plus 6 is also available in 4” and 6” (400 and 600) as a Plus 6...
Today’s motion control systems require motors that do many different things, such as precise positioning or controlled torque. Servo motors allow for better control of these conditions by allowing a high rpm spin at low torque yet slowing down and increasing torque as states require. With position sensors, encoders, and gearing, microcontrollers can sense the actual versus the desired position and correct it to allow rotors to turn to the machine gear or wheel to the precise position required. These DC motors can be either positional, where precise rotor control is needed, or continuous, turning clockwise or counterclockwise at different programmed speeds. Servo motors are available in numerous sizes, and torque ranges and cost-effective to achieve control in high torque situations. They are best suited for speeds over 2000 rpm where high torque is needed. However, they are limited in positional rotation to 180 degrees. Allen-Bradley has a long history of quality, durable, and robust...
As the de facto standard for industrial programmable logic controllers, Rockwell Automation’s line of Allen-Bradley PLCs covers the full spectrum of application scales, from hobbyist to multi-site systems. In this article, we’ll examine one of the most popular and cost-effective PLC options in Allen-Bradley’s catalog: the MicroLogix 1400 family. MicroLogix Family Overview The MicroLogix series sits at the micro-scale end of Allen-Bradley’s PLC offerings, just under small-scale options such as the CompactLogix series, and farther yet under large-scale solutions including the flagship ControlLogix series. These series groupings aren’t meant to infer differences in quality or reliability – these names only refer to the scale of the applications each family is designed to serve. Where a ControlLogix PLC may control an entire plant, a MicroLogix PLC is a much better fit to control a single machine. The Allen-Bradley MicroLogix family of PLCs is based on two paramount features: compact size...
As factories and warehouses have become more connected to platforms for control and analysis of operating and production environments, equipment manufacturers have created OEM equipment to operate with more precision. This means that more than ever, reliable and efficient control of motor speed and performance is critical. When control systems require more than just stop and start or on and off applications, variable frequency drives (VFD) can be used to deliver the right amount of voltage and frequency to a motor so that it not only does what it is required to do, it also does so with precision and safety for both operators and equipment. Because using VFDs allows full control of operating motors, companies can reduce both cost and energy consumption while achieving very tight process control for their operation. Allen Bradley Low Voltage VFDs Allen Bradley’s VFD solutions cover a wide range of sizes and applications for any control and automation needs through its PowerFlex® VFD...
Motion control sits at the heart of most manufacturing and warehousing applications. With accurate motion control, system designers can create closed loop, efficient systems that optimize performance across a wide range of industries. One common requirement for many systems is for low inertia servo motors. Depending on the final product or application, low inertia servo motors are used in a variety of applications. These applications range from packaging and converting where consistent, high speed high torque requirements drive the value of the system. They are also used for electronics assembly, as well as in big ticket items such as automotive and metal forming where consistent performance and reliability are key. The Value of Low Inertia Motors Simply stated, low inertia motors are small and have a small spindle inertia. In high volume environments when the motor is operated almost continuously, a low inertia motor will impart both low inertia and heat to the system. In systems...
