Can i control a 5 phase stepper motor with omron PLC???

I want to control a 5 phase stepper motor with 0.72 deg/step with a omron cpm2a plc. We know that the pulse output from the CPM2a is single phase. So, is this PLC can use to control the 5 phase stepper motor????

Are you trying to connect the PLC output directly to the stepper motor? Normally you would have an amplifier connected to the motor. The input to the amplifier would be the pulse train from the PLC or other stepper controller. At each pulse, the amplifier switches on or off the appropriate combination of phases to make the make the motor rotate.

So, the PLC could control the stepper motor by outputting a pulse train to the amplifier. You need to check to see if you can get the speed you need. What is the maximum output frquency you can achieve with this PLC? A 10 KHz output will give you 1200 RPM. You won't get 10 KHz by having ladder logic turn an output on and off. Does this PLC have a dedicated pulse output where you can specify a frequency?

yes. i m connecting the plc with pulse train output to the driver card of the stepper motor. The plc pulse train is a single phase output with frequency 20 Hz to 2KHz. So, i want to know, what is the meaning of 5 phase stepper motor. Is it having any relation with the pulse output from PLC??? can my plc able to control this 5 phase stepper motor????

I dont understand, how u calculate the 10KHz equel to 1200RPM???Can u show???? Thanks a lot.

The 5 phase stepper motor is older technology, not seen as frequently these days as it used to be. I'm not sure if anybody is still making them. You need to make sure that your amplifier is compatible with the motor.

For each pulse at the amplifier input, it will command the motor to rotate one step. You stated 0.72 degrees per step. This is 500 steps per revolution. 1 KHz is 1000 pulses per second, corresponding to 2 motor revolutions per second, or 120 revolutions per minute.

THis may help you with doing some calculations with a stepper motor
http://www.orientalmotor.com/support/pdf/D043-D046.pdf

As you can see Oriental Motors deals with stepping motors but I think the 5 phase is being phased.

Bergher Lahr/Sig Postiec (owned by Schneider Group) is another company with a site that has info on stepper motors.
http://www.sig-positec.com/

I have a tutorial pertaining to 5 phase stepper motors if I can locate it...boss calling me now so gotta go.

what is the meaning of plc single phase pulse output????

You are trying to make a relationship to the PLC phrase "single phase pulse output" with the stepper motor phrase "five phase stepper motor." They are two different concepts.


This is the general layout:
PLC single phase output > stepper motor amplifer > five phase motor

The PLC (CPM2A) generates a single line pulse output which is fed into the input of the stepper motor amplifier. The stepper motor amplifer generates a five phase output which drives the five phase stepper motor. You might want to think of the amplifier as a single phase to five phase convertor.

Sooo...

you can commonly find today 2, 3 and 5 phases steppers. 2 phases models usually have a basic step angle of 1.8deg (200 steps/rev) and 5 phases models a step angle of 0.72 deg(500 steps/rev), but depending of applications, allmost all resolutions can be found, from 20 to 10000 steps/rev (think that steppers are present everywhere! for rotational or linear movements). To be simple, the motor's phase number basically relates to the number of built-in coils too, in which an excitation sequence in sent in order to obtain the rotational movement.

But different wiring methods permit to choose various motor torque and speed characteristics. Even if you speak about some 2 phases motors, depending on products, you can sometime wire 8 leads. This way, you can arrange phases as desired, with serial or parallel wiring of individual coils. Motors are provided with 4, 6 or 8 leads for only two phases motors... for bipolar type only...

With 500 steps/revolution, a 5 phases stepper allows to obtain smoother basic movements (compared to 2 phases models with 200 steps/rev). But since a 2 phases motor can be driven in "micro-step" mode, you can obtain very smooth rotations with them too. A micro step mode (i.e 10µsteps/step = 2000 steps/rev with a standard 2 phases motor) means that another excitation sequence is sent to the motor, for finest movements. Consequence : smoother movements, with torque losses. Many drives allow to run in micro-step modes : from 2 to 256 µstep/step in common ranges.

From PLC output : your output transistor generates pulse trains, sent to your electronic drive. Each time you send a pulse, a step sequence is sent to the motor. If you run in full step mode, you need 500 pulse for a full revolution. Always see the torque/freq curves or your motor and read what kind of frequency range can be used. With your 2khz output, and a 5 phases motor at full step, you should always work in the right range (= high available torque). Never start from 0hz, and prefer freq. between 500 and 2000hz, if your PLC can provide trapezoidal movement patterns.

What about the sign information ? Two ways are commonly used : pulse + sign and CW/CCW outputs. It depends on both PLC and drive specifications.

Feel free to give further informations about your project if you need some practical details.

Regards