News: Did You Know?

This Did You Know? article covers the process of closing a simple analog position loop using a Q program and an Applied Motion stepper drive with differential inputs.

Some step motor applications require an operator to adjust a rotary valve or air vane and cannot use a homing sequence on power-up. The operator just needs to turn a control knob and have the load move to the correct location.

Did you know the same technology that drives the new Five-hundred-meter Aperature Spherical Telescope (FAST) in China is available to Applied Motion Products customers everywhere? Initiated in 1994, the FAST telescope is a key national scientific and technological infrastructure project in China. Standing in a region of typical Karst depressions in Guizhou province, the dish-like telescope will be as large as 30 football fields.

Servo amplifiers need to be tuned to optimize performance for each application. This normally straightforward task can be complicated if the speed and torque requirements vary greatly during machine operation, for instance when there are distinct loaded and unloaded states. The SV200 Series Servo Drives provide a couple of useful options to resolve this dilemma.

Most popular hybrid step motors have a "step angle" of 1.8 degrees. The 1.8 refers to the angular distance between full steps and is a bit of an anachronism. Most applications now employ microstepping to electronically divide the step size to as low as 51200 steps/revolution. Nonetheless, another class of hybrid motors exists that provide a full step size of 0.9 degrees.

In our post What Do NEMA Sizes Mean?, we examined the NEMA frame sizes in which step motors are made. Larger frame sizes produce more torque. But this is not a one dimensional process: within a given frame size, the motor length can vary and that also affects torque. Because step motors require expensive tooling in order to be produced economically, a fixed rotor length is chosen, as is the stator that surrounds it.

In our last post, we explored the possibility of connecting a step motor to a small gas engine for use in recharging a 12 volt battery. The effort resulted in a computer model which we hoped to use to optimize the design without having to expend excessive time and effort on trial and error. Our first concern was whether the step motor had the optimal number of winding turns on the stator. Changing the winding of a step motor is a difficult experiment because of the complexity of reprogramming a winding machine and loading it with a different size wire.

Step motors are prized for their ability to provide precise positioning without a feedback mechanism or closed loop control system.  This inherent precision is owed to the fact that hybrid step motors have toothed rotors and stator that create an electromechanical gearing system to increase the resolution provided by rotating the stator field by 50X.  Move the field by 90° (one full step) and the motor shaft moves by just 1.8°.

(The OSI Model, Part 1 may be found here.) Welcome back! Last time we covered the basics of the OSI model and briefly discussed two of the most common forms of serial communications: RS-232 and RS-485.  This time we'll take a quick look at TCP/IP and conclude with a look at how something like standard snail mail might look if we press-fit it into an OSI model mold.

Applied Motion Products stepper and servo drives have supported sensorless homing for several years. Also known as “hard-stop homing”, there is no need for a hard-wired home sensor (hence the name sensorless) when using this method because a physical hard stop is being used to stall the motor, create a position following error, then automatically recover from the fault by moving off the hard stop and setting the home position.

Q programmer is a versatile application that permits programmed motion to be combined with digital I/O. The combination can occur in several ways: sequentially, simultaneously and armed-at-all-times.

Large format 3D printer manufacturer 3DP Unlimited had an incredible showing at the 2015 Consumer Electronics Show in January. Because of their ability to print large items to scale and not just in miniature, 3DP Unlimited set a new bar for additive printing capabilities and garnered a great deal of attention from the press.

Applied Motion Products has always prided itself in developing easy-to-use products, including both hardware and software. Programmable drives can turn what would otherwise be a basic stepper or servo drive into a very smart independent controller that will auto-execute a customized Q program upon power up and react to numerous input conditions, including digital inputs and motor position feedback. This type of technology has been around for years here at Applied Motion.

Many of our stepper and servo drives have I/O available for connecting to external devices such as control signals, incremental encoders, limit switches, proximity or photoelectric sensors, PLC I/O, lamps, and other devices. The drives come with digital inputs, digital outputs, and single-ended analog inputs (analog inputs can be wired together as 1 differential analog input).

Applied Motion Products’ Integrated step motor drives offer an ideal motion control solution for an ever increasing variety of 3D printers. 3D printer technology is being applied to an amazing number of applications including: Fabrication of aircraft parts, personal items including shoes, medical devices, carbon fiber structures and even biological systems. 3D printing will revolutionize the manufacturing industry, enabling developments that previously could not be imagined.

In the third part of our Industrial Networking focus articles, we will take a look at how Applied Motion products can be easily integrated into an existing machine or new machine design using the EtherNet/IP protocol. First, let’s take a look at the products that have the EtherNet/IP networking capability.

Did you know that Applied Motion Products supports a wide range of Industrial Networks? Manufacturers and OEMs have recognized the production gains that can be realized from increased data communication and machine control by using industrial networks. The number of industrial networks, the number of network nodes, and the capabilities provided by industrial networks have increased dramatically over the last decade.

Applied Motion Products offers connectivity to EtherNet/IP, CANopen, Modbus RTU, and RS-232 and 485 serial networks for our stepper and servo products.

As a salesperson, I love when I am asked questions. Asking me questions is a great way for me to better understand your needs. There are no dumb or stupid questions - questions are how we learn. Too often, salespeople don’t ask enough questions and we lose opportunities to solve a problem or sell a solution. So here are some questions I would ask Applied Motion Products if I was buying from the website or a sales manager. Some of the answers may surprise you!

Does your motion control application involve more than 1 axis of stepper or servo? Applied Motion Products multi-axis control, SiNet Hub Programmer™ software and one of our SiNet™ Hubs may be the right solution. SiNet Hub Programmer™ takes our single-axis Si Programmer™ software and augments it to handle up to 4 or 8 axes, depending on whether you use it with the SiNet™ Hub 444-DIN or SiNet™ Hub 8.

LabVIEW® software from National Instruments is a powerful tool that is commonly used to control automated processes found in a laboratory setting, test environment, or even an industrial facility. By using the data provided to a LabVIEW program as input variables, the outputs can be automatically adjusted with the use of function blocks to provide closed loop process control. These outputs can be specially programmed to send commands to an Applied Motion Products stepper or servo system that is the foundation of the motion control system for your particular automated process.

Because we have added innovations like DSP based resonance cancellation and closed loop control, stepper drives and step motors are being used more extensively than ever. This has highlighted a need for ruggedness and reliability step motors have not always been known for. Customers tell us motors need to withstand harsh environments and be easily installed and maintained in factory automation and even outdoor uses.

Encoder following, which is also known as A/B Quadrature control mode, can be utilized on stepper and servo drives sold by Applied Motion Products. An encoder is a feedback device most commonly found in servo systems where positional feedback is essential for closed-loop control.

The Move Profile Analysis tool allows you to graphically view the move profile you are programming. Not sure how your stepper motor will perform when you change one or more characteristics of the move profile, such as, distance, accel, decel, or velocity? You do now! The Move Profile Analysis Tool allows you to make one or more changes and then test the move in your application via the Test Profile button. Your stepper motor will move when you click the Test Profile button so be prepared and use caution.

In another recent Did You Know? article we introduced you to some of our customized motors. Our customized solutions also include drives and software. One example is a three axis microstepping drive with an integrated PC for an engraving machine (top photo). We saved the customer money and simplified their assembly by integrating three of our popular 3540M step motor drives with a personal computer.

Applied Motion can customize your motor. As with our other value added capabilities, such as mounting encoders and gearheads, we offer quick turnaround on custom shaft treatments and connectivity options.

Stepper drives from Applied Motion Products provide many advanced control features. Microstep Emulation is one feature that should interest all users. Microstepping was a major advancement in step motor technology when it was introduced to the market many years ago. However, because of the many low-frequency indexing systems still in use to this day, not all users have been able take advantage of it. Fortunately, Microstep Emulation from Applied Motion makes microstepping available to all system designers and machine builders.

Our ST5 and ST10, STAC5, STAC6 and STM stepper drives with Q programming are well suited for labeling applications. A product sensor can be tied to one of the digital inputs, triggering a WI (Wait Input) command when the product nears the labeling position. To prevent wrinkling or tearing, the label must be applied at the same speed the product is traveling on the conveyer.

Applied Motion Products has a long history of making products that are simultaneously powerful and easy to use. While this remains a priority for us, the sheer number of variables can seem a bit daunting to a newcomer. Let’s take a step back and examine the different options.

There are some applications using Q Programmer™ that require the operator to make a slight “trim” adjustment to a move parameter. An HMI can be used to do this but a simpler approach, using the drive’s analog input, is often easier and less expensive. The example program below shows trim capability built into an application. An STM24QF integrated stepper is used in this example but all Q drives have an analog input so all can use this approach.

With the advent of the EtherNet/IP line of products, drives from Applied Motion Products can now communicate with the world’s leading PLC vendors using the most popular native communication protocol: EtherNet/IP. With its unparalleled power and flexibility, EtherNet/IP has captured a huge part of the industrial marketplace. Unfortunately, configuration and use of EtherNet/IP devices has historically been a difficult and mysterious process for many users.

Applied Motion offers a range of high performance, true planetary gearheads that complement our offering of step motors, integrated steppers and servo motors. These gearheads offer high torque output, high efficiency and high shaft loading capacity.

Many servo and stepper systems require a clamping circuit to limit increases in power supply voltage when the motor is decelerating under load. As the motor reduces its speed it increases the voltage on the DC bus of the drive. This is commonly referred to as “regeneration”, and occurs when DC motors are driven by their load. Generally, this situation occurs in cases where a large inertial mass is being decelerated.

For many modern machine builders, touchscreen HMIs have become an essential component for granting machine operators intuitive and functional access to system parameters, diagnostics and data.

Digital Signal Processing (DSP) provides the foundation for much of the latest stepper control innovation. Precision current control via custom algorithms within the DSP and encoder feedback allow today’s stepper drive technology to detect stalling of a step motor. Applied Motion Products takes this technology a step further by providing the logic necessary to allow user control of the system current in a near-stall situation to ride through or prevent most stall conditions.

Applied Motion drives with Q programming functionality allow the user to program many different types of moves, interface with various I/O, and perform complicated tasks previously reserved for standalone motion controllers or PLC’s. The Q language is actually pretty easy to use, but the first project in any new language can be intimidating. To help accelerate the learning curve, Applied Motion Products has included a number of sample programs with every Q Programmer installation.

With the introduction of the new STAC5 stepper drives, Applied Motion has expanded what used to be called the STAC6 Configurator™ software to include both the STAC5 and STAC6 stepper drives. Accordingly, the name of the software has changed to STAC Configurator™

For applications that require S-curve acceleration and deceleration ramps, Applied Motion servo drives offer an easy-to-use jerk filter. The jerk filter is set in Hertz within Quick Tuner™, Applied Motion’s servo configuration and tuning software. It can also be set with the SCL command KJ. The lower the Hertz value the more pronounced the S-curve profile will be.

S-curve acceleration/deceleration ramps are beneficial in positioning systems where instantaneous changes in speed may cause the load to jerk excessively. One example is when the load is connected to the motion actuator via a long moment arm.

Applied Motion Products’ DSP-based stepper drives with encoder options offer a unique feature. The stall prevention feature of the STAC6, ST5, ST10 stepper drives and STM integrated steppers not only prevents stalling, but maintains the position of the motor at rest as well. This feature is called position maintenance.