A servo is a control system that enables the output variable to accurately follow or reproduce the input variable. With increasingly demanding requirements for motion control, servo control has emerged. A servo motor, also known as an actuator motor, is used as an actuating element in an automatic control system to convert received electrical signals into angular displacement or angular velocity output on the motor shaft. It is divided into DC and AC servo motors. Its main characteristic is that when the signal voltage is zero, there is no rotation, and the speed decreases at a constant rate as torque increases. Servo positioning is mainly achieved through pulses. Essentially, when a servo motor receives a pulse, it rotates by an angle corresponding to that pulse to achieve displacement. Because the servo motor itself has the function of sending pulses, it sends a corresponding number of pulses for each angle of rotation, thus forming an echo or closed loop with the pulses received by the servo motor. The system will know how many pulses were sent to the servo motor and how many pulses were received. In this way, it can precisely control the rotation of the motor to achieve precise positioning, down to 0.001 mm.
In bus servo systems, pulse mode is typically used in simpler servo applications with less demanding requirements. As is well known, there is a certain time delay in sending and receiving pulses. Bus servo drives (i.e., absolute servos or EtherCAT servos) in bus control mode can achieve true synchronization because bus communication is faster and can directly send speed or position settings. Therefore, servo applications are based on bus control.
Our servo drive series
| Servo drive model | model | Pulse input | Analog quantity | With feedback | RS485 | CANOpen | M2 Bus | M3 Bus | EtherCAT |
|
T3a/T3L Series |
Double plate pulse type | √ | √ | √ | √ | ○ | ○ | ○ | ○ |
|
T3D Series |
Single board 17/23 bit absolute value type | √ | √ | √ | √ | ○ | ○ | ○ | ○ |
|
T3DF/C30G Series |
Single-board pulse incremental type | √ | √ | √ | √ | ○ | ○ | ○ | ○ |
|
T5a Series |
485 Absolute value type | √ | √ | √ | √ | ○ | ○ | ○ | ○ |
|
T5ML(M2)/T6M(M3) Series |
M2 Bus Type | ○ | ○ | ○ | ○ | ○ | √ | ○ | ○ |
| M3 Bus Type | ○ | ○ | ○ | ○ | ○ | ○ | √ | ○ | |
|
T6E/T6DE Series |
EtherCAT Type | ○ | ○ | ○ | ○ | ○ | ○ | ○ | √ |
|
T3DC Series |
CANOpen Type | ○ | ○ | ○ | ○ | √ | ○ | ○ | ○ |
|
S3a Series |
Spindle type | √ | √ | √ | √ | ○ | ○ | ○ | ○ |
|
T3M/T3G Series |
Maxim Pulse | √ | √ | √ | ○ | ○ | ○ | ○ | ○ |
| Wide pulse type | √ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | |
|
T3C Series |
Dual-plate 17/23-bit absolute value type | √ | √ | √ | √ | ○ | ○ | ○ | ○ |
| √ means standard configuration, ○ means not configured | |||||||||
Bus servo drives offer high flexibility and cost-effectiveness. Compared to pulse-type servo drives, their advantages are as follows:
1. Saves wiring costs, reduces wiring time, and lowers the probability of errors. One bus communication port of the controller can be used to connect multiple servo mechanisms, and a simple RJ45 port can be used for insertion between servo mechanisms to shorten the construction cycle.
2. More information: Fully digital information interaction allows bidirectional transmission of many parameters, commands, status, and other data; pulse mode can only transmit position or speed information in one direction and cannot obtain more servo status or parameters.
3. High precision, digital communication: No signal drift, command and feedback data accuracy up to 32 bits.
4. High reliability, strong anti-interference ability, and no pulse loss. Pulse/direction control is unreliable at high speeds.
5. Bus servo reduces overall system cost. When there are two or more servo mechanisms, no controller configuration adjustments are needed. Pulse-type servos require additional pulse or axis control modules. When there are many servo systems, even higher-level controller hardware may be required to meet the requirements.
6. Bus servo allows for the development of devices with more powerful software without additional hardware or wiring: The controller can monitor servo motor faults in real time via the bus and display them on the teach pendant. Simultaneously, the controller can monitor the actual position and speed of the servo motor and automatically adjust servo parameters as needed. Servo parameters can be set in the teach pendant, eliminating the need for modifications on the servo panel; this is simple, intuitive, and less prone to errors.
7. Adopting a standard motion function block library improves programming and debugging efficiency: The bus system solution avoids the problems of large programming volume and complex debugging in traditional pulse direction control modes, improving efficiency and saving costs and time.
8. Enables remote control, which is very convenient when the production line equipment is long or the number of servo devices is large, with low installation costs.
9. Enhanced maintainability, more status information, and diagnostic information. Bus-controlled CNC and motion control are very popular in Europe and America.