1、Step from the Angle of

It refers to the theoretical value or average value, that is, the theoretical value of the rotation Angle of the motor rotor for each pulse signal.

2、precision

　　Usually referred to as the maximum stride error or the maximum cumulative error, expressed directly as a percentage of the mechanical Angle or step. Step distance error and accumulated error are two concepts, on the numerical is different also, this means that the definition of accuracy is not completely unified. From the perspective of use, for most of the time, measured by the cumulative error of accuracy is more convenient. The largest cumulative error, is to point to start from anywhere, through any step, between the maximum angular displacement error. Due to the stepping motor turned a circle, the movement of the rotor are repetitive, so the definition of precision, can be considered within a circle, a maximum of any step between the rotor angular displacement error.

3、torque 

　　Holding torque (or positioning torque), refers to a maximum of winding is not energized the electromagnetic torque, or corner does not exceed a certain value of torque value. Usually reactive stepper motor holding torque to zero, unless have special produce holding torque loading, i. if thousands of types of permanent magnet stepper motor, has a certain holding torque.

　　Static torque is not change control winding turtle state, the electromagnetic torque of the rotor without turn. It is a function of winding current and disorder within the Angle, when the value of the constant current in the winding, disorder of static torque and Angle of the relationship is called torque Angle characteristics. Corresponding to the disorder of a certain Angle, static torque value is the largest, known as the largest static torque Mk), its value depends on the current status and the value of the current in the windings. Regulated torque is refers to the maximum output torque value of the rotor rotating cases. It related to the frequency of the operation.

      In recent decades, the stepper motor has made great progress, the performance index has been greatly improved, and the main frequency index of the improvement, on the one hand, from the improvement of the structure of the motor components themselves, design and process to achieve, but also from the improvement of the driver. At present, the maximum starting frequency of the small step stepper motor can reach about 2000~5000 steps/second, and the maximum running frequency can reach 16,000 steps/second, while when the driver adopts the so-called 'subdivision' line, the maximum running frequency can reach 160,000 steps/second or higher.

　　In general, large size or large power stepper motor, it is not easy to obtain high frequency index, in order to solve this contradiction, the use of hydraulic torque amplifier. The stepper motor is combined with a hydraulic torque amplifier to form a series of products called 'electro-hydraulic stepper motors' with turnstiles.

　　If the stepper motor can be driven directly without hydraulic torque amplifier, the hydraulic system can be saved, which is naturally very desirable. Therefore, the development of high-power stepper motor with high technical indicators has been a topic of general concern in recent years.

     For high-power stepper motor, its efficiency is very important. The perfection of the motor structure and the improvement of the driving circuit make the efficiency index of stepper motor greatly improved. On the other hand, the stepper motor operation stability has been improved and can operate stably in a wide frequency range. No serious oscillation occurs.

4、Frequency should be accomplished

　　Within a certain frequency range, the stepper motor can run at will without losing a step, then this maximum frequency is called response frequency. Usually use start frequency (medium) as a measure, it is can not throw step to start the limit of the frequency, sometimes called a sudden jump frequency. And a drive for a certain motor, the start frequency values related to the size of the load, load contains the size of the load torque and load moment of inertia of the two aspects of meaning..

5、Operating frequency (or continuous frequency) 

　　Refers to the frequency of continuous rises, electric function do not break the limit of the frequency step run. Its value is related to the size of the load. Obviously, in the same load conditions, continuous frequency (f) value is higher than or start frequency response frequency value (,). Stepper motor as the servo motor and drive motor, its main technical indicators include: interval, the output torque, starting rate of 0, operation frequency, accuracy and efficiency, etc. Due to the stepper motor used in the digital program control system, the system work speed, depends on the frequency control of motor, using pulse per second per second (or steps) to measure, So frequency index of the stepping motor is often particularly important. As for the main requirements start frequency or frequency index, is to look at the specific situation of system, some system with fixed load, often require a constant speed, are not allowed to work have change, such as 'a hole machine' (tape punch), step motor is applied in this system, the main demand load cases start frequency index, operation frequency index have no meaning here, on the contrary in other system, the speed of work can and have change, such as nc machine tools is like this, In this case, the main thing is the running metrics.

In the last twenty years, the stepper motor has a great development, the performance index has been greatly improved, and the main frequency index of the improvement, on the one hand, from the improvement of the structure of the motor components themselves, design and process to achieve, but also from the driver improvement. At present, the maximum starting frequency of the small step stepper motor can reach about 2000~5000 steps/second, and the maximum running frequency can reach 16,000 steps/second, while when the driver adopts the so-called 'subdivision' line, the maximum running frequency can reach 160,000 steps/second or higher.

　　In general, large size or large power stepper motor, it is not easy to obtain high frequency index, in order to solve this contradiction, the use of hydraulic torque amplifier. The stepper motor is combined with a hydraulic torque amplifier to form a series of products called 'electro-hydraulic stepper motors' with turnstiles.

　　If the stepper motor can be driven directly without hydraulic torque amplifier, the hydraulic system can be saved, which is naturally very desirable. Therefore, the development of high-power stepper motor with high technical indicators has been a topic of general concern in recent years.

　　For high-power stepper motor, its efficiency is very important. The perfection of the motor structure and the improvement of the driving circuit make the efficiency index of stepper motor greatly improved. On the other hand, the stepper motor operation stability has been improved and can operate stably in a wide frequency range. No serious oscillation occurs.