Stepper motor drives

Hi,
I am developing a control system for the speed control of a gas turbine. So for that i need to change my present manual movement of the fuel valve to one by a stepper motor. The valve is very sensitive, so i need a high resolution stepper motor (100,00 steps per revolution). I have a NI CRIO and have a digital I/O module fit on the chasis. With the existing setup, i would like to know what is the best stepper motor i can get in the market with least modifications to my current setup. If such a thing is not available, then what is the next best choice. Can anyone please help me out on this.
Regards,
Umesh

Hi Umesh,
could you please provide some more information? First I feel a bit uncertain by the resolution that you are looking for? Do you mean 10,000 steps per revolution or 100,000 (with a missing zero at the end)?
If it's 10,000 steps/rev, you could use a standard stepper motor (200 steps/rev) with x50 microstepping. If it's 100,000 you definitely will need a gear box. In general I would also recommend a gear box if you need 10,000 steps/rev, as x50 microstepping is already a quite high value, resulting in reduced accuracy (steps are not evenly distributed anymore).
Some other questions:
Could you please provide information about the required velocity and acceleration values?
What about the inertia of your valve? Any idea about motor sizing?
Which cRIO digital I/O module are you using?
Are you using NI-SoftMotion?
Have you thought about using cRIO drive interface modules (makes programming much faster and easier)?
Have you already decided which power drive to use?
Kind regards
Jochen Klier
National Instruments

Similar Messages

What are the pin connections from 7764 to stepper motor drive

what are the pin connections from UMI 7764 to stepper motor drive? I use PCI 7340 controller. Third party driver is not branded, but assembled. It has 3 inputs, one for (A,A/) one for (b,b/) one for enable, apart from ground pin.

Dear enigmata,
Here is a link to the UMI Manual that describes the signal connections:
http://www.ni.com/pdf/manuals/321941b.pdf
What you really need is the documentation for the input of the "translator" mentioned on the left side of the last diagram you posted. It is still not possible to tell which of you drive inputs correspond to step and direction (or CW, CCW) because in the circuit that you posted, these signals have already been converted by other circuitry in the drive to the A, A/, B, B/ output signals for the stepper motor.
I agree with Jochen: Without the documentation you will need to test it out as he described in his last post.
Best Regards,
Nate Holmes
National Instruments

How can I control a stepper motor drive using a DAQ card?

I need to control a simple CW/CCW stepper motor drive using a DAQ
card. I simply need to output a 5 volt signal and then a drop in
the signal, and so on 200 times or steps for 1 revolution. I have
desiigned the basic program, but do not know how to output the
appropriate signal.
Cheers,
Matt

What DAQ card do you have? Ideally, one with a counter output to generate the steps, where you can control frequency. If you try to start the motor too fast (acceleration or abrupt application of fast pulses) it may stall out. Search in Help/Search for Examples for 'frequency' and 'pulse' for example of frequency generation. You can also use a digital output on the DAQ card to control direction.
If DAQ card does not have a counter, you coul do a software timed loop to toggle a digital output to generate the pulse train. It may not be fast enough nor accurate for your application, do not know from info you have given
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Lin engineering stepper motor driver

Has anyone out there written a motor driver VI for a stepper motor from Lin Engineering? Specifically, I'm looking for a VI to control a Silverpak 23CE with integrated controller (model 5718X-01P). A VI for any of Lin's integrated controllers might be useful as an example.

Hey jaydiep,
How does the Silverpak 23CE connect to the computer? Is it through serial, ethernet, etc? This will help in determining how you would need to communicate with this device.
Thanks!
Andy F.
National Instruments

How can i control a 3rd party stepper motor driver

I want to control a 3rd party stepper motor hardware driver througt labview.The company has given me a C program.Can somebody help.I'm new to labview.
Thanks in advance
Rajan

Hi Rajan,
The LabVIEW may be able to control the motor depends on the bus used for communication and what the C program does.
For example, if you connect to the motor using a simple bus, such as RS-232 (serial), then you could use LabVIEW to send the commands to the instrument. For this you need the motor's command set, which should be in the motor's documentation. You can also look into the C example program you were giving and determine if commands are being sent directly using the serial port.
Another way the manufacturer might provide conectivity is using a driver. In this case, the manufacturer provides you with a library of functions that reflect the functionality of the device. You don't need to worry about the specifics of the communication bu
s. You just call the functions from this library. In this case, you can use LabVIEW's Library Function Call Node, which allows you to call C functions in dlls.
If you can include more information on how the motor is connected to the instrument and what the C code does, I could probably provide more details.
DiegoF
National Instruments.

I look for a vi which allows to drive a stepper motor drive

The stepper motor is: HIGH-RESOLUTION ROTATION STAGES of Newport

What type of stages do you have? Are they the SR50 series? If so what type of controller do you have? I have VI's for the ESP6000 PC-Based High-Performance Motion Controller (From the Newport Website) that work really well. But these won't work if you don't have the same controller. Do a search on the Newport website for your controller. They will have some VIs and utilities for your specific controller. Here is the link that will show the compatible controllers for the SR50 Series
Compact High-Resolution Rotation Stages.
http://www.newport.com/store/xq/ASP/lone.Motion+Control/ltwo.Motorized+Rotation+Stages/lthree.SR50+Series%253Cbr%253ECompact+High%252DResolution+Rotation+Stages/lfour./id.3206/lang.1/qx/product.htm
Hope this helps, Good luck!
Greg

Whether it is possible to drive a stepper motor from speedy 3's output

actually i am trying to design an voice controlled wheel chair for my application wat i have did is tat i have writern two programs using labview one is just storing my voice for four commands(namely front ,frontright ,frontleft,stop) ,tat it stores some value in an array, in my second vi i am speaking one of the four commands, and tat comands amplitude is stroed in an array and i am just comparing it with the values from the first array which i have stored it for all the four commands if any of the array value matches just approximately the i have to make the stepper motor to drive in tat direction i have done it with PIC microcontroller can u give some directions to implement using speedy33

Hi,
The SPEEDY-33 Robotics Daugher Module is an add-on device that mounts onto the SPEEDY-33 to provide more functionality. It includes:
DC Motor Drive Outputs (4)
Auxiliary Servo Motor Outputs (4)
Analog Inputs (4)
External Power Supply Connection
Details of the daughter module, you cn find at the link below:
http://digital.ni.com/public.nsf/allkb/832F1F4B12ECE1BE862572D100765898?OpenDocument
This daughter module is NOT an NI product.
For connecting a stepper motor, since speedy 33 has digital outputs, it is possible to work a stepper motor. However, you will have to connect a stepper motor drive inorder to amplify the signals to the current specifications that the stepper motor demands. Find out the specs of your motor and choose an appropriate drive.
Regards,
Mithilesh Pradhan

Difference between open loop and closed loop mode when finding the index on a stepper motor axis.

I have a test system which uses a PXI-7352 motion controller with a MID-7602 stepper motor drive to position a 200 step/revolution stepper motor with an attached 1000 line encoder. The MID-7602 is configured for 64 microsteps per step, giving 12,800 microsteps and 4000 encoder counts per revolution. The system is controlled using LabView 7.1 and NI-Motion 6.13. To home the motor, I've defined a sequence in MAX which first finds the reverse limit switch and then moves forward to the encoder index pulse.
When finding its reference in open loop mode, the system its reference at the same microstep each time. When findings its reference in closed loop mode, the system finds its reference somewhere within about a 20 microstep wide range.
I hope somebody out there with more experience with this controller can describe the difference between finding the encoder index in open loop mode and finding the encoder index in closed loop mode.
Thanks,
Mark Moss

Hello Mark,
I suspect that the behavior you are experiencing has today
with the resolution difference between your encoder and your
microstepping. Let me illustrate with an
example:
Example Setup
Stepper
Motor
NI
Motion Controller
10
steps per encoder pulse (Every 10 steps the controller gets an encoder
pulse, therefore positions 0-9 all appear to be 0 to the controller)
The
system has a maximum of 3 pull in moves set
Open Loop Scenario
The
system is commanded to go to position 9.
The
controller sends out 9 pulses.
The
motor moves to position 9.
Closed Loop Scenario
The
system is commanded to go to position 9.
The
controller sends out 9 pulses.
The
motor moves to position 9.
The
controller checks its position and sees that it is still at position 0
because it has not received an encoder pulse.
Because
the controller thinks it is still at position 0, it sends another 9 pulses
as its first pull in move.
The
motor moves to position 18.
The
controller checks its position and sees that it is at position 10 because
it has only received one encoder pulse.
Because
the controller thinks it is still at position 10, it sends1 reverse pulse
as its second pull in move.
The
motor moves to position 17.
The
controller checks its position and sees that it is at position 10 because
it has only received one encoder pulse.
Because
the controller thinks it is still at position 10, it sends and additional
single reverse pulse as its third pull in move.
The
motor moves to its final position of 16.
I believe something similar is happening with your
application as it looks for the index pulse.
Because the controller does not compensate for what it perceives as
position error in open loop mode, the motor always goes to the same commanded
position. In closed loop mode, the motor
is bouncing around inside the single index encoder pulse trying to find a
certain position.
There are several recommendations I can make towards
correcting this behavior. These
recommendations are in order of effectiveness:
Setup
your system so that there are more encoder counts per revolution than
steps per revolution.
Turn
off pull-in moves by setting them to 0 in MAX.
Use an
open loop configuration.
Play
around with the pull in window in MAX.
Regards,
Luke H

Stepper Motor with Linear Stage (Position Control and Data Acquisition)

Hey All,
So.. I've attached a stepper motor to a linear stage and so far it's working pretty well. Using a stepper motor driver from Pololu, I've simplified the control of the motor by just using output pulses from the counter output of a PXI-6143. I've tested the motor using the Pulse Train examples in LabVIEW and all is working well.
My goal now is to allow the user to collect data from a pressure sensor, attached to the linear stage, every X number of steps. From what I can tell so far, and please correct me if I'm wrong, the motor step movement is synchronised with the pulse train input. That is to say, if I give the motor a 200 step pulse train, the pulse train ouput is completed at the exact time the motor has moved 200 steps. From this, I've created a VI that moves the motor X steps, aquires the data point, and then repeats this process for the required amount of data points. The problem with this is that the motor movement is not continuous; it stops for a split second to take the data point.
How can I have labview ouput a pulse train of say 1000 steps and record a data point every 50 steps?
Two ideas that came to mind were:
1. Use the counter input port on the card to count the pulses being sent to the motor.
2. Use an encoder connected to the motor shaft.
I wanted to stay away from theses ideas though since they require resources from the DAQ card.
Thanks,
Ryan

Hi Ryan,
Just to cover all the bases, what version of LabVIEW are you using and can you attach your VI? Initially your ideas sound like they should work, do you expect to be nearly maxing out the DAQ?
Thank you,
Deborah Y.
LabVIEW Real-Time Product Marketing Manager
Certified LabVIEW Architect
National Instruments

What component I should choose to simulate a stepper motor's winding?

Dear all,
I'm now trying to simulate a chopper type stepper motor driver. In order to learn from the basic, only one motor coil was place inside the chopper circuit.
Now I choose a advanced inductor for the motor winding. I'm able to measure motor winding's parameter by a programable LZR meter and get following result:
Winding-1

Hi Jet,
I used Multisim power pro version 10.1. Sorry I forget where I found this component, but I upload the property page of this inductor. Hope you can find something.
Attachments:
Inductor_Advanced.JPG ‏72 KB

Which component I should choose to simulated a stepper motor's winding?

Dear all,
I'm now trying to design a chopper type stepper motor driver. In order to learn from basic, I build a simple circle with only one motor winding. I choose advanced inductor for motor winding. But some of the parameters required in this component cannot get.
I'm now able to measure target motor's parameters using a programable LCR meter, and get results below:
Winding-1:
Inductance : 524.6uH
Z : 392.7 ohms
Q factor : 1.758
Winding-2:
Inductance: 543.5uH
Z : 392.9 ohms
Q factor : 1.770
How to use these readings to get :
1.Inductor Self Resonant Frequency
2.Inductor Rated Current(Idc)
Or should I choose another component?
Thanks
Stanley Hsu

Hi Jet,
I used Multisim power pro version 10.1. Sorry I forget where I found this component, but I upload the property page of this inductor. Hope you can find something.
Attachments:
Inductor_Advanced.JPG ‏72 KB

Creating the Equivalent of a Single Axis Stepper Motor Indexer in a cRIO

I am looking for some FPGA code that implements a complete (or near complete) Single Axis Stepper Motor Indexer function on a cRIO using an NI-9474 DO module.
For those that aren't familiar with the term "indexer", an indexer is a pulse generation subsystem that provides pulses to a stepper motor driver that in turn drives the windings on a stepper motor. Some vendors provide a combination indexer/driver units that are issued motion commands via a number of communications standards.
The FPGA indexer should:
Output pulses in the 1Hz-800KHz range.
Run the stepper at constant velocity continuously or for a fixed number of steps.
Implement an acceleration/deceleration ramp when changing velocity.
Implement clock-wise and counter-clock-wise limit switches.
I have some demo code provided from NI that proves to me that an FPGA indexer is feasible, I am looking for some examples of a more complete indexer.

I am not aware of any examples of this being implemented. You mentioned that you have some demo code. Where did you get this, and if it wasn't from the website, could you post it? It is very possible that you can build off of this example to get the behavior you'd like.
Regards,
Burt S

Position drift during the stepper motor controlled back and forth motion

Hi everyone there,
I get a headache position drift problem during the stepper motor controlled back and forth motion. I have been wroking on the problem for the last two weeks, and still can not figure it out. So I write down here my problem in hope of getting some clues from those have some experiences in stepper motor motion control.
My goal is to use a stepper motor to drive a beam flage fixed onto the shaft to go back and forth for a certain angle, and this back and forth motion needs to be stable and reproducible within hours. With the SMD1 stepper motor driver, I only need to send in a pulse train to control the number of steps(the pulse frequency defines the stepping rate), and another pulse to controle the direction (i.e., cw or ccw). To do this, in LabView, I used the counter of the DAQ board to produce a finite pulse train to step the motor, and used one digital line to produce a pulse to switch the direction every 500ms, the timing is contolled by the software.(I used the oscilloscope to monitor these two pulses, the pulse train produced by the counter looks very stable, and delay between the pulse edges of the direction pulse and the pulse train is also very stable within 500ms. There seems no software timing problems at such a long delay.) And this labview controlled motor appears to work perfectly as I required, the motor steps a defined number of steps at one direction, and then steps back at the origin position. But after running for a few minutes, the back position shifts gradually(I can not observe a obvious shift at the first few minutes) with repect to the origin position(the position I start running). I looked it up at the manual and also the website, I got a clue that this might because the motor steps at the resonace frequency of the motor and hence misses or takes extral steps sometimes. So I changed the steping rate from 1Hz to 1000Hz to see if the shift disappears or gets smaller at certain frequency range, but the shift always exists.
I did observe the shift got smaller within the same running time when change the step model from full step (1.8degree/step)to half and quarter step model. According to this, the motor did miss steps (or pulses) during running, the quarter step model has smaller shift due to the smaller steps. But I also noticed that the motor always shift at one direction, no matter I started with clockwise or counter-clockwise, this seems really strange to me. Because the motor should shift at each direction with the same probability if we assume the motor missis steps randomly.
There is something must be wrong, either the labveiw program or the motor, but I don't even know a clue of this weird shift problem. And because of this, I haven't made any progress in my lab for the last three weeks. So any suggestions could be very helpful for solving this headache and will be really appreciated.
Thanks a million in advance and Merry Christmas!
Li

Hey, Brian Beal,
Thanks for your quick response. "accel" and "decel" mean acceleration and deceleration, am I understanding right?
If yes, then I don't have these in my LabView program, I just generate one TTL pulse train and one TTL pulse with LabView and send them into the SMD1 stepper motor driver.
The pulse train steps the shaft, and the other switchs the direction.
Yesterday, I confirmed that if the motor steer always at one direction either CW or CCW, then the stepping were very stable, no missing or extra steps happen for hours.
And I also observed that the motor took one extra step from time to time when the direction changes. And this only happens when the direction switch from CW to CCW. (bizarre!)
I guess this indicates that some pulse noise happens when the motor switch the direction too often. But I just don't have any clue for irregular extra steps.

NI Stepper motor

Hi all,
I wan t to have an stepper motor with a built-in encoder. something like ST34-8E from NI. But I'd like to know if it is crucial to drive that buy NI products or I can use any other third party product? I am thinking to use a Gecko power driver and Arduino Uno to drive and control it. It is much cheaper than using NI Compact RIO.
Thanks,
Saridar

Have you seen the new SMD series of stepper motor drives? They are low cost and couple with the integrated stepper motors (ISMs) directly. You wouldn't have to worry about setting up another 3rd party drive with the ISM. They also accept Step/Direction CW/CCW commands you could send from your arduino. Keep in mind, any trajectory generation/ motion profiling will have to be developed by you. One of the benefits of using CompactRIO or our PCI/PXI motion controllers is that you can use the motion software we've already developed in LabVIEW. Let me know if you have any questions!
Regards,
Ian K.
Applications Engineer
National Instruments

Stepper motor and NI6025E card

I want to control a stepper motor with a 6025E National instrument card. My stepper motor is controlled with a microstep controller.
Does anybody have already done that ? I am interested by some examples...
Please HELP me...
Frederic
[email protected]

I don't have any examples but I have done this before and it's not that difficult in principle. Getting precise timing can be tricky, and you'll have to use counters rather than the regular DIO ports for that kind of precision.
I had an MC3479 stepper motor driver to control each motor (there were 2). The way I did it was to use a counter for the clock signal and the DIO ports for control. I generated a gated pulse train on one of the counters, with a DIO pin (DIO 0)as the gate. The Direction, Full/Half step, and other control lines were also connected to the DIO port. I just wrote out whatever data word I needed to setup the motion I wanted, with the pin 0 high to let the clock move the motor. The motor had to be stopped by clearing bit 0, which I had after a tim
ing delay that was changed in the program. It required a little calculation to get the time delay matched with the frequency of the pulse train to get the number of steps I needed, and it was only approximate; I wasn't worried about exact position as much as being able to adjust the position dynamically.
For precise position you might try using just a digital line to increment the clock. This is simplest, but the timing will depend on your program. You can also use the other counter for a very precise gate signal, which gives accuracy as well as time-specific rotation, but uses the other counter and is programmatically more complex.

Stepper motor drives

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