- 1. PROFINET/PROFIdrive-compatible Motion Control
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The Ezi-SERVO PROFIdrive is a stepper motor control system that supports PROFINET, an industrial network based on high-speed Ethernet (100 Mbps, full-duplex communication).
PROFIdrive is the standard profile for drive technology in conjuction with the PROFINET communication systems. PROFIdrive is a powerful and mature drive control profile for any kind of application and industry usage. Based on its modular structure and manufacturer-independent device profile, PROFIdrive is easy to handle, highly scalable by its six Application Classes and defined to achieve an utmost interoperability level.
Motion control of Ezi-SERVO-PD was developed based on PROFIdrive, and the following three application classes are provided.
• AC1 (Application Class 1)
• AC3 (Application Class 3)
• AC4 (Application Class 4)
- 2. Closed-Loop System
- Ezi-SERVO is an innovative Closed-Loop System that utilizes a high-resolution motor mounted encoder constantly to monitor the current position. The encoder feedback allows the Ezi-SERVO to update the current position every 50 μs. It allows the Ezi-SERVO drive to compensate for the loss of position, ensuring accurate positioning. For example, due to a sudden load change, a conventional stepper motor and drive could lose a step but Ezi-SERVO automatically correct the position by encoder feedback.
- 3. Tuning Not Required
- To ensure machine performance, conventional servo systems require the adjustment of its servo’s gains as an initial crucial step. Even systems that employ auto-tuning require manual tuning after the system is installed. Ezi-SERVO employs the best characteristics of the stepper motor to eliminate the need of tedious gain tuning required for conventional closed-loop servo systems. Ezi- SERVO is especially well suited for low-rigidity loads (e.g., a belt and pulley system) that sometimes require conventional servo systems to use the additional bulky and expensive gearbox.
- 4. Low Heat Generation / Energy Savings (Motor Current Control according to load)
- Ezi-SERVO automatically controls motor current according to load. Ezi-SERVO reduces motor current when motor load is low and increases motor current when load is high. By optimizing the motor current, motor heat can be minimized and energy can be saved.
- 5. High Torque (Motor Voltage Increasing and Motor Current Setting)
- Ezi-SERVO features an internal voltage boosting circuit that increases the motor supply voltage above the drive’s input voltage. This elevated motor voltage enhances torque at high speeds and allows the run current to be set up to 150 %. As a result, torque is also improved at low speeds. Ezi-SERVO can achieve approximately 30 % torque improvement across the entire speed range.
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※ Torque is improved by approximately 30 % at both low and high speeds
Measurement Condition : Drive = Ezi-SERVO-PD-56L
Motor Voltage = 40 V DC
Input Voltage = 24 V DC
- 6. No Hunting
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Ezi-SERVO utilizes the unique characteristics of stepper motors and locks itself into the desired target position, preventing vibration and eliminating Null Hunt which happens to the conventional servo systems.
This feature is especially useful in applications such as vision systems in which system oscillation and vibration could be a problem. 
- 7. Smooth and Accurate Operation
- Ezi-SERVO is a high-precision servo drive, using a high resolution encoder with 20,000 pulse/revolution. Unlike a conventional Microstep drive, the on-board high erformance MCU (Micro Controller Unit) performs vector control and filtering, producing a smooth rotational control with minimum ripples.
- 8. Fast Response
- Similar to conventional stepper motors, Ezi-SERVO instantly synchronizes with command pulses providing fast positional response. Ezi-SERVO is the optimum choice when zero-speed stability and rapid motions within a short distance are required. Traditional servo motor systems have a natural delay called settling time between the command input signals and the resultant motion because of the constant monitoring of the current position.
- 9. High Resolution
- The unit of the position command can be divided precisely. (Max. 20,000 pulse/revolution)
- 10. High Torque / Continuous Operation
- Compared with common stepper motors and drives, Ezi-SERVO motion control systems can maintain a high torque state over relatively long period of time. This means that Ezi-SERVO continuously operates without loss of position under 100 % of the load. Unlike conventional Microstep drives, Ezi-SERVO exploits continuous high torque operation during high speed motion due to its innovative optimum current phase control.
- 11. Torque-Off Function
- Ezi-SERVO PROFIdrive has an input connector (TQOFF) that can Servo OFF through an external signal, regardless of PROFINET communication, to stop and protect the motor in an emergency. When the TQOFF signal is detected, the drive immediately turns off the servo, and the motor stops.
- [CAUTION] DO NOT use the Torque-Off function to stop or decelerate motors.
- 12. High Speed
- The Ezi-SERVO operates well at high speed without the loss of synchronism or positioning error. Ezi-SERVO ’s ability to monitor current position continuously enables the stepper motor to generate high torque, even under a 100% load condition.
- 13. Support for Solid & Hollow Shaft Motors
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Solid Shaft motors are general-purpose motors suitable for a wide variety of industrial applications. Brake and gearhead options are available to meet diverse system requirements.
Hollow Shaft motors feature a through-bore shaft for cable and tube routing. This design saves installation space, supports compact machine layouts, and increases design flexibility. -
Applications of Hollow Shaft Motors Motor size Solid Shaft Motor Hollow Shaft Motor
(Inner Dia. mm)Brake Option Gearhead Option 20 mm O - - O (Ø3) 28 mm O - - O (Ø6) 35 mm O - - O (Ø8) 42 mm O O O O (Ø8) 56 mm O O O O (Ø12) 60 mm O O O - -
![[Applications of Hollow Shaft Motors]](feature/Applications of Hollow Shaft Motors_eng.png)
Advantages over Open-Loop Stepper Systems
1. Reliable positioning control positioning without loss of synchronism.
2. Excellent holding torque at standstill, and automatically recovering to the original position even after experiencing positioning error due to external forces, such as mechanical vibration or vertical positional holding.
3. Ezi-SERVO utilizes 100 % of the full range of rated motor torque, contrary to a conventional open-loop stepper drive that can use up to 50 % of the rated motor torque due to the loss of synchronism.
4. Capability to operate at high speed due to load-dependent current control, open-loop stepper drives use a constant current control at all speed ranges without considering load variations. (Max. Speed : 3,000 r/min)
2. Excellent holding torque at standstill, and automatically recovering to the original position even after experiencing positioning error due to external forces, such as mechanical vibration or vertical positional holding.
3. Ezi-SERVO utilizes 100 % of the full range of rated motor torque, contrary to a conventional open-loop stepper drive that can use up to 50 % of the rated motor torque due to the loss of synchronism.
4. Capability to operate at high speed due to load-dependent current control, open-loop stepper drives use a constant current control at all speed ranges without considering load variations. (Max. Speed : 3,000 r/min)
Advantages over Servo Motor Controller
1. No gain tuning. (Automatic gain adjustment in response to a load change)
2. Maintains the stable holding position without oscillation after completion of positioning.
3. Fast positioning due to the independent control by on-board MCU.
4. Continuous operation during rapid short-stroke movement due to instantaneous positioning.
2. Maintains the stable holding position without oscillation after completion of positioning.
3. Fast positioning due to the independent control by on-board MCU.
4. Continuous operation during rapid short-stroke movement due to instantaneous positioning.