Control step motor explanations

[bazogui]

Hello,

I would like to control a step motor with computer through a cRio solution and a module: NI9512

I already saw what can be requested for the experiment:

• A controller Ni cRio 9073, in order to plug the module
• A power supply 24VDC
• Step motor

Nevertheless I noticed that I could also have needed a Step driver (like the P7000). What is its role? What the difference between the Step driver and the module NI9512?, Does I required the both ?

Thanks you for your responses,

Regards

[Jochen]

Hi bazogui,

a step drive like the P70530 is required for your setup to drive the motor power. The 9512 generates the move trajectory (acceleration and deceleration ramps), outputs the control signals (step and direction) and provides inputs for position feedback (quadrature encoder) and limit switches.

The P7000 drive converts the control signals to current patterns for the motors. This is not a digital (on/off) power signal, but the drive has to take care of the microstepping, which means to drive a sine/cosine approximation current waveform through the motor phases.

The P7000 drives are a very good fit for the 9512 and fitting cabling is available. The P70530's form factor is similar to the form factor of cRIO modules and it's quite flexible in terms of input and output power, so I would recommend to use this drive.

I hope this makes things clearer.

Kind regards,

Jochen Klier

National Instruments

[bazogui]

Hi,

thanks you for your response, it's clearer.

I have juste one question more..

In order to have 3 axes to control, do I need of 3 modules Ni 9512 and 3 P70530 drives?

According to you, wath is the best judicious choice for this with a cRio solutioin ?

Thanks  you for your help,

Regards,

Azogui Benjamin

[Jochen]

Hi,

one 9512 provides connectivity for one stepper axis. The same is true for the P70530 drives.

Using the drive interface modules is probably the most reasonable method to drive stepper motors with a cRIO system. It requires no FPGA programming and provides a very easy to use API (NI-SoftMotion). 

Of course you also could use digital I/O modules and FPGA programming, but this would result in significantly more work. With the drive interface modules you should be up and running in several hours (including cabling and configuration). With the manual approach the setup could easily take several days to weeks (consider extensive testing and recompiling of your code). If you need to meet very special requirements, this is still worth the efforts, but for standard stepper motion control tasks I strongly recommend to use the drive interface modules.

Kind regards,

Jochen Klier

National Instruments

[bazogui]

Hi,

Ok, if I properly understand, in order to control 3 step motors with cRio solution, I need 3 stepper drives P7030, 3 modules NI 9512, the controller and the power supply.

I am wondering if a PCI solution would be more suitable, and less expensive?

I already saw that can be required: 1 PCI 7334, 3 Driver P7030, 1 UMI 7764 and the power supply for the UMI.

According to you, Is that correct? How to make the connection between the UMI and the three stepper drives P70530? Is it also easy to use and to program with Labview?

Thank you in advance,

Kind regards,

Benjamin Azogui

[Jochen]

If a PC meets your requirements, the suggested components are also fine. CompactRIO provides industrial rugeddnes, real-time control, a programmable FPGA and industrial rated I/O modules. If you don't need these features, it's probably a bit oversized for a mere motion control application.

On the P7000 drive's product page, you will find cables to connect the UMI to the drives and there is also a ready to use configuration file for the P7000 drives to configuer the PCI-7334 correctly. So yes, this setup is quite easy to use.

Jochen

[bazogui]

Hi,

I think that the cRio solution could be more suitable for my setup, and I am about to make the order.

So, to resume all the components that I need to control the 3 axes, there is:

3 stepper driver P70530

3 module NI 9512

1 controler NI cRIO 9073

1 power supply 24 VDC PS 15 (for the controller)

3 cable NI 9512 to P70530

Power supply for step driver

Does this configuration seem you complete and correct?

Is that possible to have one power supply for the three stepper drives? 

Also, I would to know if there exist a rack mounting or a support for the 3 stepper drives that are requested in my setup.

Many thanks for your informations

Benjamin A.