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Check out Galil’s New H-bot Firmware in Action March 9, 2016

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Read more @ http://www.galil.com/news/whats-new-at-galil


Galil’s product family can be viewed at the link below-



Introducing Galil’s New C Programing Library June 10, 2015

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gclib is a C-compatible application programming interface (API) for communicating with Galil motion controllers and PLCs.
Features include:

  • Currently supports Windows, Ubuntu, Red Hat, and Fedora.
  • C interface for maximum compatibility and portability.
  • Extensive examples and support for multiple compilers.
  • Open source component allows modifications in the field.
  • Open source implementation of the GalilTools Communication Library (Galil.h) for existing code.

In February Galil introduced a new C application program interface (API) library.  This library gives programmers access to powerful routines to interact with Galil motion controllers in a wide variety of application development environments.  To download the APIs (Application Programming Interfaces) click on  http://www.galil.com/downloads/api

Click on the link below to view Servo2Go’s family of Programmable Motion Controllers from Galil Motion Control.



Warren Osak
Toll Free Phone:  877-378-0240
Toll Free Fax:       877-378-0249

Tags:  Galil, Servo2Go, Motion Control, Motion Controller, Motor Control, Automation, Servo System, Stepper System, C Library, API, Application Programming Interfaces, C Programming Library

Electromagnetic Interference (EMI) Prevention April 8, 2015

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From: White, Don. Electromagnetic Compatibility: What is it?  Why is it needed?  Instrumentation & Control Systems EMI/EMC Course.

Principal coupling paths:

  1. Transmitter-to-transmitter EMI via antenna coupling of both source and victim equipment in which the source transmitter falls in the passband, adjacent channel, harmonics of the transmitter and/or spurious responses in the receiver.
  2. Common-impedance coupling, in which two or more units or systems are connected to the same safety wire, ground grid or plane at more than one place (multipoint grounding.)
  3. Common-mode and ground-loop coupling, in which radiated fields couple into ground loops that convert interference to undesired common- mode currents, and to differential- mode currents (the failure mechanism.)
  4. Differential-mode coupling, in which radiated fields penetrate signal and control cables to develop interfering voltages at the victim.
  5. Power-line coupling, in which either radiated EMI picked up by power lines or transients directly generated on the power lines couple to the victim’s power cable and from there to victim circuits.

Most frequent EMI violations in industrial control systems:

  1. Ground loops and other ground problems:
    No matter what you might think, you do have many ground loops – some of which may include cable shields.  Here are a few examples:
  • Both commercial power and UPS safety grounds entering the cabinet
  • Cabinet grounded to building ground grid and/or steel and indirectly grounded to other ground points
  • Internal dedicated analog reference (returns) grounded via long external runs to building ground
  • Analog and logic returns connected together (often indirectly) and grounded to the cabinet
  • Uncovered cable trays multipoint grounded to building steel

The solution is to open all or most ground loops.  If ground loops persist or cannot be opened, place hefty snap-on ferrites on all ground leads/cables at cabinet entry points.  In addition, avoid long ground cable runs; their high inductance at RF makes them worthless as EMI grounds, and they act as carriers of interference currents.

  1. Incorrectly terminated cable shields

Sensor, control device, and digital cable shields (i.e., shielded twisted pairs) are rarely terminated at the cabinet entry.  Instead, they are terminated inside on a terminal strip via pigtails and jumpered to the cabinet frame.  This allows radiation from cable shields to take place inside the cabinet, which compromises its shielding effectiveness.

Electromagnetic compatibility (EMC) solutions include terminated cable shields via connectors at the cabinet wall, a shielded terminal strip plate a the entry, or installing snap-on ferrites on every cable shield or group of shields at the cabinet entry.

  1. Unfiltered power mains

Often, raw, polluted AC power entering the cabinet meanders to the location of the DC power supply before filtering – if filtering is, indeed, even done.  This allows radiation to take place inside the cabinet from the outside power and safety leads, and this significantly reduces the cabinet’s shielding effectiveness.

Because there are multiple DC power supplies inside the DCS cabinet, all raw AC power should be surge suppressed and EMI filtered, and/or a shielded isolation transformer should be used upon entry to the cabinet.  Once contaminated power enters the cabinet, it is too late for subsequent AC regulators to remove the potential damage.  Even ferroresonant and other regulators can be parasitically bypassed by crosstalk at high frequencies, especially if the AC input and DC output are on the same terminal strip.

If filtering can’t be done upon entry, at least install snap-on ferrites at all power and safety leads entering the cabinet.

  1. Cable tray crosstalk

If analog sensor and control device cables must share the same cable tray, at least position the sensor cables on one side of the tray and the controlled device cables on the other side.  Use tray separators.  Since most cable trays, unfortunately, are open at the top, ferrites can be added every 10 or 20 feet.  Check their effectiveness with clamp-on RF current probes and a spectrum analyzer or wide-band oscilloscope.


Tags:  EMI Prevention, EMI Interference, Electromagnetic Interference

Servo Motors and Horsepower Rating March 27, 2015

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Reprint of TrueTech Specialty Motors March 26, 2015 Blog

Servo Motors and Horsepower Rating

Servo Motors are not usually rated in Horsepower because:

  • Servo Motors are usually used in incremental motion applications where the speed is frequently (and often rapidly) changing and delivered torque ranges from near nothing to brief periods of high peaks with an average of up to the continuous motor rating. These motors usually have a low inertia to power ratio.
  • Motors that are typically rated in Horsepower are usually used in applications where the motor runs at a constant speed (and fixed input voltage) and delivers a slightly varying torque. These motors usually have a high inertia to power ratio.

Certainly, a Servo Motor CAN be rated in Horsepower but it has to be at a specific load point that is at the motor’s continuous torque rating and a specific speed within the motor’s speed range. The bus voltage of the driving control also has to be known.

Power is a value that cannot stand by itself while specing out a motor and in the physical realm (Power = Speed * Torque). When you are looking at getting a motor’s parameters defined with power, it is necessary to provide speed and/or torque values. You can calculate one of those three variables when provided with the other two. Keep in mind that BLDC (servo) motors have various modes of operation and the power of the motor in use could be lower, or even potentially higher, depending on the application. For example, two motors continuously rated at 1 HP, one motor run at 1000 RPM and the other 15000 RPM, would definitely have at a minimum different voltage constants and physical components constructing the motor.

Horsepower is a Torque – Speed product

If the two values are not “fixed”, Horsepower becomes a slippery value. A handy conversion that is easy to remember is that 1 HP = 1,000,000 oz-in-RPM. Knowing this, a motor with a label rating of 1/2 HP at 1750 RPM (common AC motor) can deliver up to 285 oz-in (17.85 lb-in) (1.49 ft-lb) of torque. That would be a fully loaded rating. If the motor is running at less than rated load, it is not delivering 1/2 HP.

Similarly, a Servo Motor typically has a Continuous Torque rating, a Peak torque rating, a Ke, and a maximum operating speed. It may have a torque/speed curve based on a driver bus voltage and the continuous torque rating. A Horsepower rating for that motor could be the point on the curve where the speed-torque product is at its highest. However, if the motor is run slower or faster than this point, or the torque is lower than the continuous, the HP output will be lower.

Consequently, a typical servo application wherein the motor is expected to run at various speeds, directions, and torques, a Horsepower rating is essentially meaningless and the torque-speed curve is of greater value. However, in a power transmission application where the motor runs at a fixed speed and required torque is a specific maximum value, a Horsepower rating is of value.


Tags:  HP Rating, Servo Motor, Servo Motor Horsepower Rating

White Paper: Selecting a Brush-Commutated DC Motor February 11, 2015

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Permanent magnet direct current (DC) motors convert electrical energy into mechanical energy through the interaction of two magnetic fields. One field is produced by a permanent magnet assembly; the other field is produced by an electrical current flowing in the motor windings. The relationship between these two fields results in a torque that tends to rotate the rotor. As the rotor turns, the current in the windings is commutated, or switched, to produce a continuous torque output.

Brush DC motors can be operated over a wide range of voltages, speeds, and loads. Output power for a brush DC motor is a product of speed and torque; input power is a product of the applied voltage and motor current. The first step in motor selection is to decide if you are going to need a gearbox or not. This will typically depend on your maximum required load speed. A good rule of thumb might be to use a gearmotor if your maximum speeds will be below 1000 RPM, and use only a motor if your maximum speeds will be above 1000 RPM.

Pittman's Brush DC Motor Family

Pittman’s Brush DC Motor Family

If you are going to use a gearbox, start by selecting one that meets the torque requirements of your application. Gearboxes are usually rated by their maximum allowable output (load) torque. Once you have chosen a gearbox type, the appropriate ratio must be selected. Determine the ratio by dividing the maximum acceptable input speed to the gearbox by the maximum desired output (load) speed, then choosing the closest available ratio. Acceptable gearbox input speeds vary, but are typically on the order of 6000 RPM. Calculate the motor speed and torque requirements using the following equations:

  • WM = WL x N and TM = TL / (N x n)
    where WM = Motor Output Speed
  • WL = Load Speed
  • N = Gear Ratio
  • TM = Motor Output Torque
  • TL = Load Torque
  • n = Gearbox Efficiency

Once the motor requirements have been determined, choose a motor type and frame size capable of producing the required motor torque. For continuous operation, select a motor with a continuous torque rating greater than that of the required torque. For intermittent operation with a sufficiently short on-time, select a motor with a continuous torque greater than that of the rms value of the required torque.

Motor manufacturers will provide continuous torque ratings for their motors under certain operating conditions, including a specified ambient temperature (often 25 degrees C. or 40 degrees C.) and thermal resistance (dependent on whether a heat sink is utilized.) Take care to read the fine print when comparing continuous torque ratings as they may need to be adjusted if these assumptions do not match your actual operating conditions.

After a frame size has been selected, the proper winding needs to be specified. Generally, voltage and torque will be known values, and speed and current will need to be determined. The best winding choice will be that which comes closest to providing the desired speed and current draw given the supply voltage and load torque. The governing motor equations to determine speed and current follow:

  • W = (VS – I x Rmt) / KE and I = TL / KT + INL
    where W = Speed
  • VS = Supply Voltage
  • I = Current
  • Rmt = Motor Terminal Resistance
  • KE = Back-EMF Constant
  • T = Load Torque
  • KT = Torque Constant
  • INL = No-Load Current

While these equations are suitable for most applications, it is important to realize that they are only the basic formula and do not take into account thermal considerations. Motor heating will alter some of the parameters in these calculations, including resistance, torque constant, and back-emf constant. Accounting for these effects adds significantly more complexity to the process. Finally, when going through any calculations, make sure to maintain consistency among units of measure.


“Off-the-shelf” brush-commutated DC motors are the exception, rather than the rule, and they are frequently customized to meet specific design and performance criteria for an application. Among those components typically specified:

Optical Encoders: Since closed loop servo applications require velocity and/or position feedback, common motor options include incremental optical encoders, which supply accurate position, velocity, acceleration, and direction feedback for precision motion control. Encoders can be added to any motor or gearmotor with wires or side-exiting power terminals and can be metal-housed or open air. They can be factory-mounted or prepared for mounting in the final stages of end-product assembly. Encoders are usually specified with either two- or three-channel, TTL compatible quadrature outputs. The maximum frequency, which limits the maximum operational speed, is typically 100 KHz. In a three-channel unit, the third channel provides an index signal or pulse once per revolution of the codewheel.

Another encoder option, the rotary pulse indicator (RPI), is a single-channel unit with open-collector or TTL-compatible outputs. RPIs are low-cost solutions for appliance applications that need 120 counts per revolution or less without direction-sensing capabilities.

Shafts: The shaft of any motor can be customized with a flat, journal, cross hole, keyway, slot, groove, gear, or pulley. These options can be combined to meet application requirements. As examples, a cross hole can allow a pulley to be pinned to the shaft, or a journal can include a groove. A variety of other combinations are possible. Shaft material can be customized from the standard 416 Stainless steel to other grades, such as 303 and 316 Stainless with different Hardness ratings. Standard and common optional shaft diameters include a variety of sizes from 4mm to 8 mm and from 5/32-inch to 3/8-inch.

Gearheads: Gearheads increase output torque and decrease speed. These functions and their efficiency vary with different models and applications. For most applications a spur gearhead is flexible enough to meet specific torque, noise, and cost requirements. Standard spur gearheads feature sintered nickel-steel gears, which provide moderate power handling with average audible noise. The sintering process allows for close tolerances (AGMA Q7-8) at a low cost. The sintered gear functions as a lubrication holder and helps dampen sound. When more strength is required, a hybrid cluster (an assembly of a cut-steel pinion and a sintered gear) or precision cut steel gears can be chosen. Other gearhead options include planetary gearheads for lower backlash and much higher torque or Delrin (moldable polymer) gears that produce less noise than sintered gears.

Wire and Cable Assemblies: Custom wire and cable assembly options are designed to speed motor installation and boost component reliability. Almost any connector style and wire type can be specified for motors, gearmotors, and encoders.

EMI/RFI Suppression Components: A number of cast and stamped component solutions have been developed to reduce the amount of electrical noise generated by a motor. For low-frequency RFI (typically below 30 MHz) capacitors are generally effective, and there is an inverse relationship between the value of the capacitor and the attenuated noise frequency. Capacitors installed by the motor manufacturer enable strategic placement inside the motor frame for optimum filtering as close to the noise source as possible. For high-frequency noise (generally above 30 MHz) ferrite beads can help reduce RFI. A combination of ferrite beads and capacitors provides the most effective suppression by creating a low-pass LC filter that is inductive-capacitive at low frequencies and dissipative at high frequencies.

Mounting for each component may vary from slipping ferrite beads over wires to soldering chokes near the motor terminals, depending on the best solution for the application.

Brakes: Developed as a safety and energy-saving feature, rear-mounted power-off and power-on electro-magnetic brakes prevent a motor or gearmotor from rotating freely. Brakes typically are offered for 16 and 40 oz-in static torques and 12, 24, 28, 48, and 90 VDC operation, although other voltages, including 120 VAC, are available. A power-off brake stops a motor when power is removed and releases the motor when power is reapplied. In low-duty applications, the brake saves energy by maintaining a known motor position without power. An added safety feature is that should power be lost while the motor is lifting an object by pulley or lead screw, the brake will lock the motor and prevent the object from falling. A power-on brake holds the motor in place upon application of power and releases the motor when power is removed.


When brush-commutated DC motors are used to drive gears or pulleys, avoid excessive side loads. These can push a motor to an extreme and lead to motor failure. If side loads will be present, ball bearings are usually recommended. Environmental conditions will impact, too, on effective brush DC motor operation and performance. For example, the moisture in the air acts as a lubricant and, where humidity is low, the resulting lower lubrication will accelerate brush wear and shorten motor life. (Special brushes are designed to solve this problem.)


  • Know the proper rating of the motor for an application and recognize and understand the importance of continuous operation vs. duty cycle.
  • Do not press fit components on a motor’s shaft (in any direction) without proper support at the other end of the shaft. This action could lead to motor failure.
  • Do not apply adhesives or other foreign material directly to shafts that could contaminate the bearings. These could negatively affect performance. If such materials are to be applied, it is generally advised to apply them to the component to be secured to the shaft to reduce the chance of contamination.
  • Consult with your motor manufacturer before, during, and after a motor is specified for an application.


NEMA publications represent the most relevant sources for standards relating to traditional motor products and devices. Other standards include ANSI and IEC for rotating machinery, as well as IEEE standards for motor-related test procedures. A “CE” designation assures compliance with appropriate standards for those products used in the European marketplace. In addition to product standards, a set of quality oriented standards applies to motor suppliers. Those manufacturers that have achieved ISO certification demonstrate documented adherence to procedures and operations consistent with international quality standards.


The primary cause for failure of brush-commutated DC motors over time is ongoing brush wear. The traditional method for mounting copper or silver graphite brushes in motor assemblies has been to solder the brushes onto standard cantilever springs to enable the required constant contact with the commutator. This conventional spring design, however, carries inherent drawbacks as force levels diminish over time, and motor failure can result.

The problem can be overcome by housing the brushes within a specially designed cartridge and utilizing torsion springs to ensure desired even force over the life of a motor. The cartridge, which fits into the motor base, consists of a two-piece, high temperature plastic snap-together assembly in which each of two brushes is seated securely within its own specially constructed slot. This design effectively restricts the brushes to traveling in a track in a desired linear motion.

The cartridge design further provides for an ideal region of pressure (6-8 lbs. psi) for the brushes to withstand the detrimental effects of mechanical wear. Other typical causes that can result in motor failure include motor overloading, contamination of the armature, and electrical or mechanical malfunctions. There are many others, depending on motor design, operating parameters, and in-use service and safeguards.


Users can save money (and headaches) at the outset by partnering with a quality motor manufacturer from the very beginnings of the design stage. This will minimize (and likely eliminate) costly mistakes and ensure that a motor performs as intended and required in an application.

This early involvement also can open a window to available motor features and options, which could help initially to reduce labor and material-handling costs for the customer and provide for easier motor installation.

View our Products: DC Mini Motors: 12V & 24V

For more information, please contact:

Warren Osak
Toll Free Phone:  877-378-0240
Toll Free Fax:       877-378-0249


Tags:  DC Motor, Brush Motor, Servo Motor, Brush Servo Motor, Brush-Commutated DC Motor, Brush-Commutated Motor

Slotted vs. Slotless Motor Technology January 23, 2015

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Slotless vs. Slotted BLDC Motor

Slotless vs. Slotted BLDC Motor

When first introduced, brushless DC motors, despite their many advantages, were cast as a costly alternative to brush-commutated motors and were typically only specified for low-power applications where long life was the primary desired requirement. Without the mechanical brush-commutator mechanism that would wear and eventually result in motor failure, brushless motors could be relied upon to deliver performance over time. As for other advantages, conventional wisdom held that brushless motors provide high speed and fast acceleration, generate less audible noise and electromagnetic interference, and require low maintenance. Brush-commutated motors, on the other hand, would afford smooth operation and greater economy. In the past decade, though, brushless motors have gained broader appeal and greater acceptance in industry for a wider range of applications previously dominated by brush-commutated products, due in part to dramatic reductions in the cost and size of electronic components and advances in motor design and manufacturing.

At the same time, manufacturers have further sought to challenge conventional wisdom by improving brushless motor design in an effort to combine the traditional advantages of brush-commutated and brushless types. A noteworthy example of how far these innovations have progressed involves the slotless (instead of slotted) construction of the brushless motor’s stationary member, or stator.

The slotless stator design originated with the goal to deliver smooth running performance and eliminate cogging, which is an unwanted characteristic especially in slower-running applications (less than 500 rpm). The absence of cogging is, in fact, the most-often cited reason for selecting a slotless brushless motor…

Click on the link below to view this complete White Paper.


For more information, please contact:

Warren Osak
Toll Free Phone:  877-378-0240
Toll Free Fax:       877-378-0249


Tags:  Servo2Go, slotted motor, slotless motor, BLDC motor, servo motor

Build or Buy? January 14, 2015

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Build or Buy?

Important factors to consider when deciding between building a linear positioner in-house or purchasing an existing technology


Click on the link below to download this article originally published in the November 2014 issue of Manufacturing Automation.




Galil Now Offers EPICS Driver Baselines October 3, 2014

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EPICS stands for Experimental Physics and Industrial Control System.  It is a set of open source, distributed software tools used extensively for scientific instruments such as particle accelerators, telescopes, and other large-scale experimental installations.  Using EPICS, scientists are able to network together arbitrarily complex systems of nodes, such as motion controllers, PLCs, instrumentation, and other software and hardware agents.  Using a read/write protocol called Channel Access, the Input/Output controllers (IOCs), can interact while providing high-level functionality and interaction for sophisticated physics applications.

Galil now offers the EPICS Driver Baseline.  As shown in Illustration 1, this software provides communication drivers and device support to create a Galil EPICS IOC.  The software comes with the basic support needed for building a feature-rich IOC including the following:

– Support for the DMC-3x01x, DMC-4000, and DMC-41×3 Ethernet based controllers.  Galil communications libraries allow extension to PCI-based controllers such as the DMC-18×6, DMC-18×2, and DMC-18×0.  The array access feature allows easy extension to Galil’s line of RIO-47xxx PLCs.

– Basic Motor Record Support, which is an EPICS IOC Record designed specifically for motion controllers.  See Table for some example fields imn the EPICS Motor Record.

Using the EPICS Channel Access feature, Galil array data can be read and written directly from the EPICS network.  Coupled with DMC code embedded on the controller, the EPICS user can easily extend the EPICS support to any desired Galil firmware feature or programmable function.  The array access feature, which is part of the Galil EPICS driver, allows quick deployment in an EPICS system without requiring a deep knowledge of EPICS IOC development.


Field Description
ACCL Acceleration, Deceleration specified in seconds. Duration of the accel/decel region.
ATHM At home. State of HM input.
DHLM Dial High Limit. Essentially a soft forward end of travel.
DLLM Dial Low Limit. Essentially a soft reverse end of travel.
DMOV Motion complete Boolean. 1 = finished; 0 = moving.Uses motion complete bit from data record.
EGU Engineering units. Galil baseline normalized to counts/steps.
ERES Encoder step size in EGU
HOMF Home Forward. Set to 1 to initiate home.
HOMR Home Reverse.  Set to 1 to initiate home.
HVEL Homing velocity.
ICOF Integral Gain (KI normalized). Valid range; 0.0 <= ICOF <= 1.0
JAR Jog Acceleration (EGU/s/s).
JOGF Jog motor forward.  Set to 1 to initiate jog forward.
JOGR Jog motor reverse.  Set to 1 to initiate jog reverse.
JVEL Jog Velocity.
MRES Motor step size (EGU)
PCOF Proportional Gain
REP Raw Encoder Position
RMP Raw Motor Position. The contents of the hardware’s step-count register.
STOP Stop motion. Set to 1 to initiate stop (ST)
VAL Desired position. Will call a PA/PR to move the motor.
VELO Velocity (EGU/s)
VMAX Max Velocity (EGU/s)

Table 1: Examples of helpful Motor Record Fields


Click on the link below to view Servo2Go’s family of Programmable Motion Controllers from Galil Motion Control.



Warren Osak
Toll Free Phone:  877-378-0240
Toll Free Fax:       877-378-0249

Groschopp Tech Tips: How to Check for a Damaged Armature September 3, 2014

Posted by Servo2Go.com in Product Video's, Technical Support Information.
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3 minute YouTube Video

Here are three quick checks you can perform with a volt/ohm meter to test a DC motor armature winding to determine if a motor armature is functioning properly.

Click on the image below to view this video.


Tags:  Groschopp, motor winding, motor testing, motor armature, PMDC motor, PMDC Gearmotor, AC Motor, AC Gearmotor, DC Motor, DC Gearmotor, Electric Motor

Motion Control Technology Handbook August 21, 2014

Posted by Servo2Go.com in New Product Press Releases, Technical Support Information.
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Published by Manufacturing Automation

Manufacturing AUTOMATION’s ‘Motion Control Technology Handbook’ is a digital magazine that focuses on Automation and Motion Control products and systems.  Posted on MA’s website as an interactive flip-style magazine, the Technology Handbook provides market information, technical product information, tutorial video’s, white papers as well as trends within the Motion Control Industry.

Motion Control Handbook Snippet

This is a must-read for all to OEM machine builders, end users and system integrators.  Click on the link below to view the Handbook.


Tags:  Motion Control, Motor Control, Machine Control, Servo Systems, Stepper Systems