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.

Use a motor as a generator, you say? Surely those are completely different things. Turns out, they aren’t. If the motor is driving the load, it’s a motor. If the load is driving the motor, it’s a generator. Most of the motor applications I work with involve point to point position control: in getting from Point A to Point B, the motor must accelerate to some speed, then decelerate such that the motor speed reaches zero just as we arrive at Point B. During acceleration, energy is supplied to the motor as it drives the load.

 All Q programmable drives provide digital inputs that can be used singly or in combination. In programs where only a single input must be examined the TI (Test Input) command is commonly used. The TI command can be used sequentially to test many inputs one right after the other, but it can be cumbersome to create a decision tree in this fashion. A better method may be to bit-wise AND the I/O register. The result is a number that represents the ON & OFF conditions of only the inputs of interest.

Applied Motion Products has delivered our first IP67 compatible motor! An OEM found our new line of brushless DC motors and performance matched drives to be the perfect choice for their project - with one exception, one BIG exception. The motor needed to survive full immersion in liquid for a 24 hour period.

You probably already know about the excellent networking capability of the Applied Motion Products DC stepper offering. Did you know that Applied Motion also has CANopen, EtherNet/IP Modbus RTU, and the ASCII based Streaming Command Language (SCL) networking options for the SV7 Series DC servo amplifiers? Additionally, Modbus TCP/IP is just around the corner with a scheduled release in Q1 2015.

Brian Mason, Regional Sales Engineer – Southwest

Applied Motion Products is like an iceberg. At the tip, you know them to be a renowned manufacturer of high-precision, cost-effective motion control products. Below the surface however is where the real action is! Advanced algorithms such as step smoothing filters, harmonic waveform smoothing and electronic damping propel our technology ahead of the curve. Let’s dive into these technology characteristics with competitor data analysis to showcase why ours is better.

A question often asked is this: which is better, servo or stepper? Perhaps a more precise question is: for which applications are servos the best choice and for which are steppers the best choice? As with many things, the answer is not always simple and there are many factors to consider. The common answer is: servos are better for high speed applications and steppers are better for low speed.

 

Q Programmer is a very versatile programming platform where motion is involved. Incremental positioning, absolute positioning, encoder following, pulse and direction, analog velocity, multi-segment moves and torque control are some of these motion modes. However, machines are becoming more sophisticated, and often require the motion controller to have PLC logic capabilities as well as motion capability.

The STM24 and ST Series are Modbus compatible and ready to plug and play with HMI’s and PLC’s.

If you read Ken Doner’s Industrial Networking article in the March newsletter, you know that Applied Motion is big in real time connectivity. This month, we show examples. The device below is a linear actuator driven by an Applied Motion STM24QF integrated drive+motor. The STM24 accepts Modbus commands from an HMI over RS-232.

Applied Motion Products offers a standard range of gear ratios (3:1 up to 100:1) in its complete line of planetary gearheads, compatible with both NEMA and metric motor frame sizes. Planetary gearheads are ideal for high torque motion control applications requiring precise positioning, high efficiency, and low backlash. In applications where there is a large load-to-rotor inertia mismatch, these gearheads are the perfect compact solution.

Brian Mason, West Regional Engineer

   The Life Sciences industry has seen tremendous growth across many disciplines including scientific informatics, drug discovery devices and nanotechnology. From 3-D printers capable of producing functioning organs, to pumps capable of delivering liquids on a pico-liter scale, the future for Lab Automation is looking bright. Now is the time to collaborate with chemical engineers and scientists that are prototyping the next product that will pave the way to a higher quality of life.

Applied Motion Products offers a wide and ever-increasing range of products for your automation needs. That said, we’ve all been in a situation where an exact solution to a particular need simply doesn’t exist. You might need something that simply hasn’t been done before, or maybe an existing product is painfully close to what you would call “ideal” except for one particular feature that you need to have modified in some way.

Q Programs are normally executed one line at a time. This ensures precise sequencing of events in the program. There are applications however where motion must occur simultaneously with other events and we offer a multitasking mode to accomplish this. Multitasking allows you to launch a move then perform other operations while the motion is occurring. At the end of the move you can re-synchronize motion and program execution with a WM command.

You can access all of the available videos from either the support dropdown link in our navigational bar or by checking out the video linked on relevant product pages. These '2 Minute Intro' videos as well as our training videos are great ways to become more familiar with our products. Speaking of new releases, stay up to date by visiting the News button on the homepage. This button takes you to all the archived news feeds and you can search for past articles based on keyword.

Microstepping in most Applied Motion drives is variable in increments of 2. Many stepper drives offer a selection of microstepping resolutions that include commonly used values like; 1,000, 5,000, 10,000, and 20,000 steps per rev. These are commonly selected by mechanical dip switches. Most of Applied Motion’s intelligent drives allow you to select between 200 steps per rev and 51,200 steps per rev in increments of 2.

For most systems, a new or replacement drive will be commissioned with ST Configurator before installation into the machine. This is a one-time event for a drive, and if a predefined configuration file is used it takes only a few minutes to complete the procedure. It does however, require a PC to load the configuration data to the drive. ST Configurator remains the recommended way to configure a new drive, but for large or very complex machines this extra step is something that the operators may wish to avoid.

Did you know that Applied Motion Products will help all of our Original Equipment Manufacturer (OEM) customers protect their valuable spare parts business? Applied Motion Products will assign a custom part number or assist with designing a custom label to help your organization build brand awareness and protect your OEM machinery’s spare parts business. When any organization inquires directly to Applied Motion Products regarding a custom part number, it is Applied Motion Products’ organizational policy to re-direct that request for the custom part back to the OEM.

Many of the stepper drives we offer are set up through the ST Configurator™ software. These include the ST5/10, STAC5, STAC6 and STM drives. ST Configurator provides an easy, fill-in-the-blanks approach to personalizing the drive to your requirements. However, ST Configurator can do much more.

Applied Motion Products is pleased to announce the release of a new, 16 page Servo Products Datasheet. This colorful brochure details our broad servo system offering, with M and V series motors ranging from 50 to 750 watts of continuous output power and both AC and DC powered drives from our popular BLu and SV lines. All motors include precision incremental encoder feedback.

Hold on! No, it’s not an 80’s song. We receive calls on a frequent basis about applications requiring a holding brake. Typically in vertical applications, where the position of the load cannot be maintained when power is turned off, a spring-applied-power-off brake can be used to maintain the position of the load. Our NEMA 17, 23 and 34 frame stepping motors allow easy installation of NEMA frame size, modular, front-mounted brakes from Inertia Dynamics or Electroid.

Did you know that Applied Motion Products’ "STAC6-Q AC-powered Advanced Microstep Drive w/ Q Programming and Encoder Input":products/stepper-drives/stac6-q provides the capability to solve encoder following with registration control applications? If your application requirement is 1 HP (750W) or below, requiring high torque at low speed and rotary speeds less than 2000 RPM, consider Applied Motion Products’ STAC6-Q stepper drive.

Readers who have used our ST, STM or STAC stepper drives are probably familiar with our ST Configurator™ set up software. Many of you have also used Q Programmer™ for constructing and testing stored Q programs, and a few of you have probably updated your drive’s firmware to access the latest features.

Using a joystick to control the speed and position of a motor is an intuitive solution in many applications. Joystick operation is available with many Applied Motion drives, both stepper and servo.

When your application calls for a closed loop servo system you must take into consideration the requirements for tuning. For many systems the load inertia is the primary factor in setting the tuning parameters. Embedded in our Quick Tuner™ software are tuning files for all recommended motor-drive combinations. When choosing a motor file you will have the option of using a predetermined inertia load as indicated by a suffix in the file name.

The new STM24SF and QF models of integrated stepping motors have four optically isolated 5-24 vdc Flex I/O points. Each of these I/O points can be configured for use as either an input or as an output, or as a pre-defined function that is based on whichever STM model you are using. Assignment of the Flex I/O points is realized by use of our free ST Configurator™ software.

Take a quick walk with us down memory lane...

Some 32 years ago a young salesman from an old industrial company saw potential demand for high tech uses of step motors. When he approached his employer about this emerging market, they did not share his enthusiasm or vision.

Applied Motion has embedded help files that are tied to the physical attributes shown in our pictorial representation of the drive within the STAC Configurator™ and ST Configurator™ software applications.

Simply open the STAC Configurator™ or ST Configurator™ software and position your mouse, for example, over the I/O connector of the drive shown. Left click the I/O connector with your mouse, and a new window will open with wiring information for the selected I/O connector.

Applied Motion drives offer a variety of control modes, each with its own niche application. Most are intuitive and easily applied: pulse & direction, velocity, streaming commands (SCL). But sometimes these simple approaches don’t quite offer the elusive “perfect” solution. Analog positioning is one such application.

Many Applied Motion drives use screw terminal connectors for easy wiring. But screw terminal connectors take up a lot of space, so most of our programmable drives use higher density “D-SUB” connectors, allowing for more compact designs. Drives with D-SUB connectors include the popular ST, SV, STAC and BLU models.

D-SUB connectors are preferred by many OEMs because cable harnesses can be produced on automated equipment using the “crimp and poke” style mating connectors. Or you can hand solder wires to a “solder cup” style mating connector.

Quick Tuner™ has a built-in scope that is very useful for verifying tuning parameters. For many customers our pre-configured tuning files are all that’s needed to set the servo parameters. You can verify the system’s performance after downloading a pre-configured file by selecting the Sample Move option in the Tuning-Sampling tab. Here you can use a built-in move profile generator to actuate the motor and observe the system performance in the scope screen.

Our less expensive “S” models can be controlled in real time by a host!

Most of Applied Motion’s newer drives feature “S”, “Q”, and “Si” models. Each of these model types offer different ways for fitting into the overall control architecture of the device being designed.

• “S” models are typically controlled by an external pulse source – step & direction.
• “Q” models are programmable via an ASCII based programming language and can act as stand alone or host controlled motion controllers.

Our NEW HT24 high torque 1.8 degree stepping motors are now in stock! This new series of motors offers over 30% more torque than conventional motors of the same size. The HT24 motors mount within the same mounting pattern as our NEMA 23 frame motors.