Stepper motor is controlled by receiving pulse current to achieve speed, position and direction. The number of pulses determines the position of the stepper motor, the speed of the pulse determines the speed of the motor, and the direction of the pulse determines the direction of the motor. Now most stepper motors are controlled by using PLC to send pulses to the driver, which drives the motor to run. Pulse mode has existed for decades. For some occasions with high application requirements, pulse mode can not meet the demand, and needs bus control.
For the occasions that need to use a lot of motors, for example, many medical devices have twenty or thirty axes. If using pulse type one is not easy to control, a PLC can control six or seven axes at most. More than one motor needs more upper computers, which requires larger space volume. Most medical devices are compact and compact. Second, it is difficult to wiring with more pulse type motors. There is signal interference problem in more than one road, which leads to instability of equipment. If the bus type is used, only two signal lines and power lines are needed to connect all the motors in series. It is very convenient to design and install, and there will be no signal interference in wiring.
Some machines are equipped with computer mainframe themselves. If the pulse type is used, the use of computer mainframe cannot be brought into full play. A master computer or motion control card is needed to control the stepper motor drive system. The bus type can be directly controlled by the computer mainframe. It has the professional performance of the motion control card mode, and the cost and space volume are also compared with the other two modes. Great advantage.
Some products need moment mode in the process of movement, such as screw locker, some use moment mode, pulse type is unable to control the current of the motor to adjust the moment, and bus type can do so.
Bus mode is not only much smaller than pulse mode, but also much simpler than PLC trapezoidal program. It can also achieve simple control of motor current, voltage, temperature, blocking, current, subdivision, S-shaped acceleration and deceleration, analog quantity, synchronous instruction, off-line control, etc. Generally speaking, bus type has many new features and no disadvantages for pulse type. Bus type is the development direction and trend of stepper motor motion control in the future.