PLC stepper motor, how does PLC control the forward and reverse rotation of the stepper motor?

Control requirements: press the start button, PLC control stepper motor rotates clockwise for 3 cycles, stop for 5 seconds;Then turn counterclockwise for 2 weeks, stop for 3 seconds, and so onWhen the stop button is pressed, the motor stops immediately (the motor shaft locks).Press the offline button and the motor shaft is released. Suppose a three-phase stepper motor is selected with a step angle of 1 2.

When operating, it is set to 4 subdivisions, and the rated current is 1 75A, and when the motor is stopped (the motor shaft is locked), the quiescent current is selected as half current.

Connection between stepper motor, stepper driver, PLC:

A stepper motor is an actuator that converts a pulse signal into a linear or angular displacement. The output displacement of the stepper motor is proportional to the number of input pulses, its speed is proportional to the pulse frequency, and its steering is related to the phase sequence of the windings of each phase of the stepper motor distributed to the stepper motor. Therefore, we can use the PLC to generate the corresponding pulse and direction signals, distribute and amplify the pulse and direction signals through the stepper driver, and then control whether the windings of each phase of the stepper motor are energized, so as to control the operation of the stepper motor.

Figure 1 shows the specific port wiring circuit diagram.

For PLC, to generate pulses at the Y0 end, it is necessary to continuously turn on and cut off Y0. When Y0 is on, the positive pole of the 5V DC power supply passes through CP+, passes through the internal electronic circuit of the driver to CP-, presses to Y0 through R, passes through the COM at the output end of the PLC, and then returns to the negative pole of the 5V DC power supply, thus forming a loop. At this point, we get a high electrical frequency inside the driver, which we denote by "L".

When y0 is cut-off, the loop cannot be turned on, and a low frequency is obtained inside the driver, which we denote as 0'. The ring distributor of such a driver receives such a pulse signal like this, and then the pulse signal is distributed, and each phase winding of control stepper motor is energized sequentially. Here we use a 5V DC power supply to get a pulse of current from the stepper driver.

This control voltage is generally between DC 5V and 24V. where R is the current limiting resistor, the pulse current of the general driver is about l0mA, and the R value is about 2K. The input circuit for the reverse signal and the offline signal is the same as the input circuit for the pulse signal described above.

Panasonic PLC, Chapter 8.

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UtilizationStepper motorsThe driver can control the movement direction, running speed, running steps and other states of the stepper motor through the virtual high-speed output signal of the PLC. Among them, the high-combustion direction control of the stepper motor only needs to determine the forward or reverse rotation of the motor by controlling the ON and OFF of the U D terminal; isolate the optocouplerPulse signalInput to the CP terminal can determine the speed and number of steps of the stepper motor; Controlling the free signal allows the motor to be free.

Therefore, the control program of the PLC is quite simple, and the direction, speed and number of steps of the stepper motor can be controlled only through the output of the PLC. It does not have to be controlled by PLC.

The logical relationship of motor commutation, and there is no need to add a separate drive circuit.

Stepper motor precautions.

If the equipment is in the process of use, there is a sudden increase in temperature, or there is an abnormal noise, it is necessary to pay attention to stop the equipment for maintenance to ensure its safety in use.

In the process of operation of the stepper motor, it is also necessary to pay attention to the cleaning of the oil, and Yuanhong needs to pay attention to the cleaning of the oil stain, because in the process of using the equipment, there will be a large amount of oil stains, and the existence of oil stains will lead to abnormal use of the equipment.

The PLC only needs to change the level of the driver's directional control signal, and the motor can be reversed first.

PLC control.

There are several ways to choose a stepper motor according to actual needs:

1. By controlling the pulse, you only need to choose the pulse control stepper driver, most of the stepper drivers are pulse control, considering the control signal level of the PLC.

It is 24V, and you can choose a driver that can directly receive 24V signals, so that there is no need to connect additional current limiting resistors;

2. Through the IO control mode, you need to choose the stepper driver with built-in pulse generator, and the user can use the DIP code or potentiometer.

Speed control, motor operation can be controlled by several IO switching signals;

3. Through the bus control mode, you can choose a stepper driver with RS-485 interface, CAN interface, EtherCAT interface, etc., and the motor can be controlled through communication instructions.

There are three main control methods of PLC control stepper motor, the first is single pulse control, that is, pulse + direction. This is also the most commonly used method, and it is the control method that stepper drivers have.

The second is double pulse control, that is, forward pulse + reverse pulse. This is not a control method that all stepper drivers have.

The third is communication control, which is generally serial RS232 or RS485. There are fewer stepper drivers with this feature.

Hope...

There are two kinds of PLC control stepper motors: one is the pulse port of the PLC itself, and the other is the positioning module. It mainly depends on the number of shafts and functions of the stepper motor.

It is possible not to use a PLC, but to use a stepper driver.

The stepper driver panel operation has the function of controlling the pulse output of the stepper motor, and there are many functions, using 10gm or 20gm as the positioning module.

The definition of a stepper motor is an open-loop control element stepper motor device that converts an electrical pulse signal into angular or linear displacement.

Therefore, there must be an electrical pulse signal to make the stepper motor rotate, and the controller and PLC give this electrical pulse signal to make the motor rotate.

The driver is a must, because it is a current amplifier, the PLC can be used, the pulse can also be sent with the step controller, it can also be programmed, and there are input and output points.

The method and detailed operation steps of the stepper driver and PLC wiring are as follows:

1. First of all, hold the power supply for the 24V power supply: brown positive, blue negative, and yellow-green grounding, as shown in the figure below.

2. Secondly, connect the two wires of the motor to the "a+a-", b+b-" of the driver, as shown in the figure below.

3. Next, connect the 24V power supply "-V" to the "GND" of the drive, see the figure below.

4. Then, at this point, connect the 24V power supply "+V" to the "VDC" of the drive, as shown in the figure below.

5. Subsequently, connect the red and green front wires of the four-wire encoder to the "pul-" and "dir-" of the driver, as shown in the figure below.

6. Next, connect the Zheng Pisheng black wire of the four-wire encoder to "GND", as shown in the figure below.

7. Then, short the pul+ and dir+, and connect the white wire of the encoder to "dir+", see the figure below.

8. Subsequently, short "pul+" and "VDC", as shown in the figure below.

9. At this time, the two sets of wires of the motor have been connected, and the wiring work has been completed, as shown in the figure below.

PLC can not directly drive the stepper motor, need to pass the corresponding driver to achieve the stepper motor control, for the pulse control type driver such as EZM552, need to send the control pulse and direction signal to the driver, for the speed control type driver such as EZD552, only need to give the start-stop and direction signal to realize the control of the motor. The wiring diagram can refer to the following figure:

The drive mode of the stepper motor: you directly connect the power supply DC5V (24V), and then send out the pulse through the PLC.

1: You first connect the stepper driver with the stepper motor.

2: Connect the power supply to the stepper driver, its power supply is generally DC24V DC5V3: connect the pulse receiver of the stepper driver to the Y0 Y1 of the PLC.

4: It's OK to send a pulse with the program.

A programmable controller (PLC) controls the number and frequency of pulses and the power sequence of each phase winding of the motor, and controls the rotation of the stepper motor.

Usually the rotor of an electric motor is a permanent magnet. When an electric current flows through the stator windings, the stator windings produce a vector magnetic field. The magnetic field will drive the rotor to rotate by an angle so that the direction of one pair of magnetic fields of the rotor coincides with the direction of the stator.

When the vector magnetic field of the stator rotates by one angle. The rotor also rotates at an angle with the magnetic field.

Each time an electrical pulse is inputted, the motor rotates at an angle to take a step forward. Its output angular displacement is proportional to the number of input pulses, and the rotational speed is proportional to the pulse frequency. Change the order in which the windings are energized and the motor is reversed.

Therefore, the rotation of the stepper motor can be controlled by controlling the number of pulses, the frequency, and the power sequence of the windings of each phase of the motor.

Summary. Hello dear, the ladder diagram is as follows.

Hello dear, the ladder diagram is as follows.