The accuracy of a stepper motor system using EtherCAT communication is basically linked to the variety of incremental steps the motor undertakes throughout a single rotation. This worth, intrinsic to the motor’s building and management system configuration, immediately influences the positioning decision achievable. As an example, a motor specified with the next variety of these steps per rotation presents finer management and larger precision in purposes demanding correct angular displacement.
This parameter performs a pivotal function in figuring out the system’s capabilities in areas equivalent to robotics, CNC machining, and precision instrumentation. A larger step depend facilitates smoother movement and reduces positional errors, resulting in improved total system efficiency. Traditionally, developments in motor design and driver know-how have progressively elevated the out there step depend, thereby enhancing the precision and applicability of stepper motor programs in numerous fields.
The following dialogue will delve into the components affecting the collection of this parameter, its affect on system design, and the concerns crucial for optimizing efficiency inside an EtherCAT-based management structure.
1. Decision
Decision, within the context of stepper motor programs managed by way of EtherCAT, immediately quantifies the smallest angular increment achievable by the motor. It’s intrinsically linked to the pulses per revolution parameter, defining the granularity of movement management and the precision of positioning achievable throughout the system.
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Native Step Angle and Decision
The basic step angle of a stepper motor dictates its inherent decision. A motor with a smaller native step angle inherently presents greater decision. For instance, a motor with 200 steps per revolution has a local step angle of 1.8 levels. Growing the pulses per revolution worth with out microstepping requires a special motor with an inherently smaller step angle.
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Microstepping Enhancement
Microstepping divides every native step into smaller increments electronically, rising the efficient decision. As an example, using a microstepping issue of 10 on a 200-step motor yields 2000 efficient steps per revolution. This enhances positioning accuracy and smoothness of movement, notably at low speeds. Nonetheless, microstepping can scale back out there torque and could also be topic to inaccuracies resulting from detent torque results and driver limitations.
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Encoder Suggestions and Closed-Loop Decision
Integrating an encoder offers closed-loop suggestions, enabling finer management and error correction. Whereas the pulses per revolution set the potential decision, the encoder permits for verification and adjustment of precise place. The encoder’s decision, typically considerably greater than the motor’s native step depend, contributes to a extra exact and dependable positioning system. That is essential in purposes demanding excessive accuracy, equivalent to semiconductor manufacturing or precision robotics.
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EtherCAT Cycle Time and Decision Limits
The EtherCAT cycle time locations a constraint on the achievable decision. Speedy adjustments in goal place, comparable to high-resolution actions, necessitate sooner communication and processing throughout the EtherCAT community. Inadequate cycle time can result in delays and inaccuracies, successfully limiting the system’s potential to comprehend the total potential of its decision. Subsequently, the EtherCAT configuration and community efficiency should be rigorously thought of to keep away from bottlenecks that compromise positioning accuracy.
In abstract, the connection between decision and pulses per revolution is multifaceted. Whereas the next pulse depend usually results in finer management, components equivalent to microstepping, encoder suggestions, and the restrictions of the EtherCAT community should be thought of to make sure optimum system efficiency. Efficient integration of those parts leads to a sturdy and correct positioning system appropriate for demanding purposes.
2. Accuracy
The accuracy of a stepper motor system inside an EtherCAT community is immediately influenced by the motor’s pulses per revolution specification. This worth determines the theoretical precision of every step, forming the muse upon which total system accuracy is constructed. The next pulse depend interprets to smaller angular increments, thereby decreasing the potential for positional errors inherent in every step. Nonetheless, theoretical precision doesn’t assure real-world accuracy. Components equivalent to mechanical tolerances, load variations, and management system imperfections considerably affect the ultimate positional accuracy achieved. As an example, a robotic arm counting on exact actions will exhibit larger cumulative error if the stepper motors driving its joints have a low pulse depend, even with subtle EtherCAT management. Conversely, a excessive pulse depend motor could not ship its potential accuracy if backlash within the gearbox or compliance within the mechanical construction introduces vital error.
The EtherCAT driver performs an important function in mitigating errors and maximizing accuracy. Superior drivers make use of strategies equivalent to present management and microstepping to enhance step-to-step consistency and scale back the affect of disturbances. Moreover, integrating an encoder throughout the management loop permits closed-loop suggestions, permitting the system to actively compensate for positional errors and keep accuracy below various load circumstances. Take into account a CNC machine software the place exact positioning is paramount. Whereas the stepper motors’ pulse depend determines the theoretical decision, encoder suggestions ensures that the precise software place corresponds precisely to the programmed path, regardless of variations in chopping forces and materials properties. The EtherCAT community facilitates speedy and dependable communication between the encoder, driver, and controller, enabling real-time error correction and enhancing total machining accuracy.
In conclusion, attaining excessive accuracy in a stepper motor-based EtherCAT system requires a holistic strategy. Deciding on motors with a sufficiently excessive pulse depend is a crucial however not adequate situation. Addressing mechanical imperfections, implementing superior driver strategies, and incorporating encoder suggestions are equally essential. The EtherCAT community’s potential to facilitate real-time communication and management permits the mixing of those parts right into a cohesive and efficient system. The challenges lie in figuring out and mitigating the varied sources of error to comprehend the total potential of the stepper motors’ intrinsic decision and obtain the specified stage of accuracy within the utility.
3. Velocity
The achievable velocity of a stepper motor inside an EtherCAT-based system is basically intertwined with the motor’s pulses per revolution specification. Velocity, outlined because the rotational pace of the motor (usually expressed in revolutions per minute or RPM), is immediately restricted by the speed at which the EtherCAT driver can generate and transmit pulses to the motor. The next pulse depend, supposed to extend decision, correspondingly necessitates the next pulse frequency from the motive force to take care of a given velocity. If the EtherCAT community or the motive force itself can not maintain the required pulse frequency, the utmost achievable velocity is lowered. In purposes requiring each excessive precision and excessive pace, equivalent to pick-and-place robots, the collection of a motor with an acceptable pulses per revolution worth is essential. Selecting a motor with an excessively excessive pulse depend can restrict the system’s total throughput if the motive force and EtherCAT community turn out to be the limiting issue.
Moreover, the inertia of the load hooked up to the stepper motor impacts the speed profile. Stepper motors are recognized for his or her potential to offer excessive torque at low speeds, however their torque decreases as velocity will increase. To attain excessive velocities with vital hundreds, cautious consideration should be given to the motor’s torque-speed traits and the system’s acceleration and deceleration profiles. The EtherCAT driver performs a important function in implementing these profiles, guaranteeing easy and managed movement with out exceeding the motor’s capabilities or the community’s bandwidth. Take into account a packaging machine that should quickly place objects on a conveyor belt. The stepper motor driving the belt should speed up and decelerate rapidly whereas sustaining exact positioning. The EtherCAT driver should be configured to generate the suitable pulse patterns to attain the specified velocity profile with out inflicting the motor to stall or lose steps. Closed-loop management, using encoder suggestions, turns into important in such purposes to compensate for any deviations from the commanded trajectory and guarantee correct positioning even at excessive speeds.
In abstract, maximizing velocity in a stepper motor EtherCAT system requires a balanced strategy. Deciding on a motor with an acceptable pulse depend for the appliance’s decision necessities is important, however equally necessary is guaranteeing that the EtherCAT community and driver can ship the mandatory pulse frequency to attain the specified velocity. The load inertia, motor torque traits, and acceleration/deceleration profiles should even be rigorously thought of. Integrating closed-loop management additional enhances the system’s potential to take care of accuracy at excessive speeds. The trade-offs between decision, velocity, and torque should be rigorously evaluated to optimize the system’s efficiency for the particular utility necessities.
4. Torque
Torque, the rotational pressure exerted by a stepper motor, is intrinsically associated to the pulses per revolution parameter in EtherCAT-based management programs. Whereas the pulses per revolution primarily dictates positional decision, it not directly influences the motor’s potential to ship ample torque for a given utility. The collection of an acceptable pulse depend, subsequently, requires cautious consideration of the load traits and the specified efficiency profile.
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Pulse Rely and Torque Output
Growing the pulses per revolution, particularly via microstepping, can scale back the out there torque. Microstepping divides every full step into smaller increments, which might result in a lower within the holding torque as a result of present distribution throughout a number of motor phases. That is notably noticeable at greater microstepping resolutions. Subsequently, purposes requiring excessive torque at standstill or throughout low-speed operation could have to compromise on decision to make sure adequate torque output. For instance, a robotic arm lifting a heavy object could prioritize torque over extraordinarily positive positioning, thus requiring a decrease pulse depend or lowered microstepping.
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Driver Present and Torque Management
The EtherCAT driver’s potential to exactly management the present equipped to the motor windings is essential for maximizing torque output. Superior drivers make use of present regulation strategies to make sure constant torque supply throughout your complete working vary. The motive force compensates for the results of microstepping and cargo variations by adjusting the present to every section, thereby sustaining a steady torque output. In CNC milling machines, as an illustration, exact present management is important to stop the chopping software from stalling or chattering, guaranteeing a easy and correct end.
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Velocity Profile and Torque Demand
The speed profile, which defines the acceleration and deceleration traits of the motor, considerably impacts the torque demand. Speedy acceleration or deceleration requires greater torque output than constant-speed operation. The EtherCAT community facilitates the implementation of advanced velocity profiles, permitting the system to optimize torque supply primarily based on the instantaneous load and pace necessities. A packaging machine, as an illustration, could make the most of a trapezoidal velocity profile, requiring excessive torque throughout acceleration and deceleration phases to attenuate cycle time.
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Load Inertia and Torque Necessities
The inertia of the load related to the stepper motor immediately influences the torque required to attain the specified movement. Greater load inertia necessitates larger torque to speed up and decelerate the load. The pulses per revolution not directly impacts the system’s potential to deal with excessive inertia hundreds by influencing the motor’s out there torque. Deciding on a motor with the next torque ranking and thoroughly tuning the EtherCAT driver’s present management parameters are important for purposes involving vital load inertia. Conveyor programs, for instance, typically deal with various load weights, requiring the stepper motor to offer adequate torque to beat the inertia of the heaviest load.
In conclusion, the connection between torque and pulses per revolution in a stepper motor EtherCAT system is multifaceted. Whereas the next pulse depend enhances decision, it might probably probably scale back the out there torque. Cautious consideration of the appliance’s torque necessities, coupled with superior driver know-how and exact present management, is important for optimizing system efficiency. Balancing the trade-offs between decision, velocity, and torque is essential for attaining the specified operational traits in numerous purposes.
5. Management Loop
The efficiency of a stepper motor system ruled by an EtherCAT driver is basically depending on the implementation and traits of the management loop. The pulses per revolution parameter, whereas defining the theoretical decision of the motor, solely realizes its potential when built-in inside a sturdy management structure. A correctly designed management loop minimizes the discrepancy between commanded and precise positions, compensating for disturbances and non-linearities inherent within the mechanical system. The management loop makes use of suggestions mechanisms, typically using encoders, to observe the motor’s place and velocity, enabling corrective actions to take care of correct monitoring of the specified trajectory. The effectiveness of the management loop immediately impacts the achievable precision and stability of the stepper motor system. A excessive pulse depend, representing a finer decision, calls for a extra responsive and correct management loop to completely make the most of the motor’s capabilities. For instance, in high-precision machining purposes, a complicated management loop is important to right for errors arising from chopping forces and materials variations, guaranteeing that the ultimate product meets stringent dimensional necessities.
A number of components affect the management loop’s efficiency, together with the loop acquire, the sampling fee, and the presence of disturbances. The loop acquire determines the responsiveness of the management system to errors, whereas the sampling fee dictates the frequency at which the suggestions sign is evaluated and corrective actions are initiated. The next sampling fee permits for sooner response occasions and improved disturbance rejection. The EtherCAT community performs a important function in enabling high-performance management loops by offering a deterministic and low-latency communication channel between the encoder, the motive force, and the controller. This permits for speedy and exact trade of suggestions knowledge and management instructions, facilitating real-time error correction. In robotic purposes, the management loop should compensate for various hundreds and inertial results because the robotic arm strikes via its workspace. The EtherCAT community ensures that the management loop can reply rapidly to those adjustments, sustaining correct positioning and trajectory monitoring.
In conclusion, the management loop is an indispensable element of any stepper motor EtherCAT system aiming for top precision and efficiency. The pulses per revolution parameter defines the theoretical decision, however the management loop ensures that this potential is realized in observe. Components equivalent to loop acquire, sampling fee, and EtherCAT community efficiency considerably affect the management loop’s effectiveness. A well-designed management loop minimizes positional errors, compensates for disturbances, and permits the stepper motor to attain its full potential in demanding purposes. Challenges stay in optimizing management loop parameters for advanced programs with non-linearities and disturbances, requiring superior management algorithms and complicated tuning strategies.
6. EtherCAT Latency
EtherCAT latency, the delay between a command being issued and its execution, presents a major consideration in stepper motor programs, notably when the pulses per revolution worth is excessive. This delay influences the system’s responsiveness and accuracy, demanding cautious administration to make sure optimum efficiency.
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Impression on Positional Accuracy
Elevated latency immediately degrades positional accuracy. With the next variety of pulses per revolution, every pulse represents a smaller angular increment. A delay in pulse supply interprets to a proportionally bigger positional error. As an example, in high-resolution purposes like semiconductor inspection, even minor delays may end up in unacceptable inaccuracies, rendering the system unfit for its supposed function.
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Affect on Velocity Management
EtherCAT latency complicates exact velocity management. Stepper motors counting on frequent pulse updates to take care of a selected pace are prone to velocity fluctuations if the communication channel introduces variable delays. This could manifest as jerky actions or oscillations, notably at low speeds the place every pulse represents a major fraction of the specified movement. In robotic meeting strains, such inconsistencies disrupt easy operation and negatively affect productiveness.
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Results on Management Loop Stability
Latency introduces section lag into the management loop, probably destabilizing the system. This lag reduces the management system’s potential to reply successfully to disturbances or adjustments within the desired place. Because the pulses per revolution will increase, requiring extra frequent and exact management changes, the system turns into more and more delicate to latency-induced instability. Exact changes in PID (proportional-integral-derivative) management parameters are essential to compensate for this phenomenon.
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Compensating for Latency
Superior EtherCAT drivers and management algorithms can mitigate the results of latency. Methods equivalent to feedforward management and Kalman filtering predict the long run state of the system and modify the management indicators accordingly, successfully compensating for communication delays. Nonetheless, these strategies require correct system modeling and exact parameter tuning to keep away from introducing new sources of error. In high-speed packaging purposes, efficient latency compensation is essential for sustaining correct synchronization between a number of axes of movement.
The connection between EtherCAT latency and pulses per revolution underscores the significance of a holistic system design. Whereas the next pulse depend enhances theoretical decision, the achievable efficiency is finally restricted by the communication community’s traits and the management system’s potential to compensate for inherent delays. A radical understanding of those trade-offs is important for optimizing stepper motor system efficiency in demanding purposes.
7. Microstepping
Microstepping, a method employed in stepper motor management, considerably influences the efficient decision of the system and interacts immediately with the pulses per revolution parameter. It enhances the smoothness of movement and reduces positional inaccuracies by dividing every full step into smaller, discrete increments. This functionality is especially related in EtherCAT-based programs the place exact synchronization and management are paramount.
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Elevated Decision and Decreased Step Angle
Microstepping successfully multiplies the native pulses per revolution of a stepper motor. By energizing the motor windings with proportionally various currents, the rotor is positioned at intermediate factors between the total step positions. This leads to a finer angular decision and smoother movement, minimizing the jerky actions related to full-step operation. As an example, a motor with 200 steps per revolution, when microstepped at an element of 16, yields an efficient decision of 3200 steps per revolution. This permits for extra exact positioning in purposes equivalent to 3D printing or precision robotics.
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Impression on Torque Traits
Whereas microstepping enhances decision, it might probably additionally scale back the out there torque. As the present is distributed throughout a number of motor phases, the ensuing torque at every microstep is often lower than the torque at a full step. That is particularly noticeable at greater microstepping components. Purposes requiring vital torque at low speeds could have to stability the advantages of elevated decision with the potential discount in torque. For instance, a CNC milling machine could make use of microstepping for positive floor ending however revert to full-step mode for roughing operations the place excessive materials elimination charges are required.
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Affect on Driver Complexity and Warmth Dissipation
Microstepping will increase the complexity of the EtherCAT driver. The motive force should precisely management the present in every motor winding to attain the specified microstep place. This requires extra subtle circuitry and management algorithms. Moreover, microstepping typically results in elevated warmth dissipation throughout the driver as a result of greater switching frequencies and present ranges. Cautious thermal administration is important to make sure dependable operation. Take into account a multi-axis robotic system the place a number of stepper motors are concurrently microstepped; the combination warmth dissipation from the drivers could be vital and requires efficient cooling options.
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Interplay with EtherCAT Community Efficiency
The elevated decision achieved via microstepping can place greater calls for on the EtherCAT community. To completely make the most of the improved decision, the management system should be capable of talk and course of place instructions at a sooner fee. This requires a sturdy EtherCAT community with low latency and excessive bandwidth. Inadequate community efficiency can restrict the achievable accuracy and smoothness of movement, negating the advantages of microstepping. As an example, in high-speed packaging purposes the place a number of axes of movement are synchronized by way of EtherCAT, the community should be rigorously configured to make sure that all axes obtain place updates in a well timed method.
In conclusion, microstepping presents a way to successfully improve the pulses per revolution of a stepper motor system, leading to finer decision and smoother movement. Nonetheless, it additionally introduces trade-offs by way of torque, driver complexity, warmth dissipation, and EtherCAT community necessities. Optimizing the microstepping issue for a given utility requires cautious consideration of those components to attain the specified efficiency stability. The EtherCAT community’s potential to offer exact and synchronized management permits the efficient implementation of microstepping in demanding purposes.
Ceaselessly Requested Questions
The next addresses frequent inquiries relating to the pulses per revolution parameter in stepper motor programs built-in inside an EtherCAT community. These questions purpose to make clear technical points and inform optimum system design.
Query 1: What constitutes “pulses per revolution” within the context of a stepper motor?
The “pulses per revolution” worth defines the variety of discrete steps a stepper motor takes to finish one full rotation. The next worth signifies finer angular decision and probably extra exact positioning.
Query 2: How does the pulses per revolution have an effect on the achievable accuracy of a stepper motor system?
The next pulses per revolution usually results in larger theoretical accuracy. Nonetheless, real-world accuracy can be influenced by components equivalent to mechanical tolerances, load variations, and the management system’s potential to compensate for errors.
Query 3: Does rising the pulses per revolution at all times enhance the efficiency of a stepper motor system?
Not essentially. Whereas the next pulses per revolution can improve decision, it additionally will increase the calls for on the EtherCAT community and driver. The system’s total efficiency will depend on balancing decision with components equivalent to latency and torque.
Query 4: How does microstepping relate to the pulses per revolution parameter?
Microstepping electronically divides every full step into smaller increments, successfully rising the pulses per revolution. This enhances decision and smoothness of movement however can even scale back out there torque.
Query 5: What function does the EtherCAT driver play in managing the pulses per revolution?
The EtherCAT driver is chargeable for producing and transmitting the heart beat indicators to the motor. It should precisely management the timing and present to every motor section to attain the specified positioning and velocity. Superior drivers additionally implement strategies to compensate for latency and enhance accuracy.
Query 6: How does EtherCAT latency affect the efficiency of a stepper motor system with a excessive pulses per revolution?
EtherCAT latency, the delay in communication, can degrade the efficiency of high-resolution stepper motor programs. This delay can result in positional errors and instability. Compensating for latency via superior management algorithms is essential for attaining optimum efficiency.
In abstract, the pulses per revolution parameter is a vital consider figuring out the efficiency of a stepper motor system inside an EtherCAT community. A complete understanding of its relationship with accuracy, velocity, torque, and EtherCAT latency is important for efficient system design and optimization.
The following part will discover sensible concerns for choosing the optimum pulses per revolution worth for particular purposes.
Sensible Tips
The next outlines key concerns for optimizing the pulses per revolution parameter in stepper motor programs built-in inside an EtherCAT community. These tips purpose to offer sensible help in attaining desired efficiency traits.
Tip 1: Outline Software Necessities Rigorously: Earlier than choosing a stepper motor, completely analyze the appliance’s calls for for decision, accuracy, velocity, and torque. Prioritize these wants primarily based on their affect on total system efficiency. As an example, a high-speed packaging utility could prioritize velocity and settling time over extraordinarily positive positional decision.
Tip 2: Account for Mechanical System Imperfections: Acknowledge that the theoretical decision afforded by a excessive pulses per revolution could be masked by mechanical limitations equivalent to backlash, compliance, and friction. Tackle these imperfections via exact element choice and rigorous mechanical design practices.
Tip 3: Consider EtherCAT Community Capabilities: Assess the EtherCAT community’s bandwidth, latency, and jitter traits. Be sure that the community can assist the required pulse frequency for the chosen motor and management technique. Conduct thorough testing below practical working circumstances to determine potential bottlenecks.
Tip 4: Optimize Driver Configuration: Make the most of the total capabilities of the EtherCAT driver to maximise efficiency. Tremendous-tune parameters equivalent to present management, microstepping settings, and commutation methods to attain the specified stability between decision, torque, and warmth dissipation. Take into account implementing superior management algorithms to compensate for non-linearities and disturbances.
Tip 5: Implement Closed-Loop Management with Encoder Suggestions: Combine an encoder to offer closed-loop suggestions for exact positional management. This permits the system to compensate for errors arising from load variations, mechanical imperfections, and disturbances. Choose an encoder with adequate decision to match the specified system accuracy.
Tip 6: Take into account the Commerce-offs of Microstepping: Whereas microstepping enhances decision and smoothness, it might probably additionally scale back out there torque and improve warmth dissipation. Rigorously consider the microstepping issue to optimize efficiency for the particular utility. Take into account dynamic microstepping adjustment primarily based on working circumstances.
Tip 7: Carry out Thorough System Testing and Validation: Conduct intensive testing throughout your complete working vary to validate system efficiency. Confirm that the system meets the required accuracy, velocity, and torque necessities below varied load circumstances. Make the most of knowledge logging and evaluation instruments to determine and deal with any efficiency limitations.
These tips present a framework for optimizing the utilization of pulses per revolution in stepper motor EtherCAT programs. Efficient implementation of the following tips can result in enhanced efficiency and improved total system reliability.
The ultimate part will summarize the important thing takeaways and supply concluding remarks.
Conclusion
The previous dialogue has systematically explored the multifaceted relationship between stepper motors, EtherCAT drivers, and the essential parameter of pulses per revolution. The evaluation has highlighted that maximizing system efficiency requires a complete understanding of the interdependencies between decision, accuracy, velocity, torque, EtherCAT latency, and management loop design. It’s evident that choosing an acceptable pulse depend will not be merely a matter of maximizing decision, however somewhat a rigorously thought of trade-off that should account for mechanical limitations, driver capabilities, and the particular calls for of the appliance.
Efficient utilization of stepper motor know-how inside EtherCAT networks calls for a diligent and knowledgeable strategy. Continued developments in driver know-how, management algorithms, and EtherCAT communication protocols promise to additional improve the efficiency capabilities of those programs. Engineers and designers should stay cognizant of those developments to leverage the total potential of stepper motors in demanding purposes, driving innovation in fields starting from robotics and automation to precision instrumentation and manufacturing. Rigorous evaluation, cautious element choice, and thorough system testing are important to realizing the specified stage of efficiency and reliability.
