Stepper motor noise in 1 direction

Hi guys, i'm currently using my 6221 DAQ to provide the pulse train to drive my stepper motor (through a stepper driver). But i'm currently having a problem. The motor always produce clicking noises when i run it in 1 direction. I've tried swapping the driver and checking the cables but to no avail. Based on your experiences, what may be the problem here?

Thanks Jochen for your reply.
>As I have posted many times in this forum, I'm not a fan of using DAQ boards for controlling motors (e. g. here, here and here).
Typically the costs that you can save by using a >cheaper DAQ board
(compared to a motion control board) will be wasted rapidly by the
additional time that you need to spend for implementing a solution that
is anything but ideal.
Well, sometimes tasks are given to us just like this...
>But anyway.
>Which part of the 6221 are
you using to control the motor? (DIO, AO, Counter)? Are you using
software timing or hardware timing?
I'm using AO to generate the TLL pulses. I'm using software timing
>Have you checked the electrical
signals with a scope? There is a chance that the control signals are
pulled down by low-impedance inputs of the drive. E. g. if this happens
to the Dir+ signal, you may see the problem that you are talking about
(ok, when Dir+ signal is low, not reliable if Dir+ signal is high).
I've checked the pulse train for both forward and reverse action and it both looks the same. My Dir signal is driven with a DIO line. How would i know if my Dir signal is causing the problem? I haven't thought of probing it with the scope yet but what kind of 'unreliability' should i be looking for? Isn't it just 5V and 0V?
And if Dir signal is the problem how can i rectify it?
>By the way: NI motion control boards provide open collector outputs that allow to drive up to 64 mA.
Mine requires 1.5A
Attachments:
Pulse train.JPG ‏65 KB

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Stepper motor spinning in random directions

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Hello fair folks of the LabView forums!
I am a humble engineering student in need of some advice and input on a project I am working on.
I’ve also done a fair amount of reading on the LabView forums with people trying to use LabView and Arduino to control stepper motors, and I’ve used as much information from each as I could. However the problem I'm encountering now is one which is unique to my VI Configuration.
So, here is what has been done thus far:
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-I have created a VI, and have just recently got it to run without reporting back any errors. While I suspect the behavior I’m encountering has to do with something inside the VI, it is difficult to determine as there are no errors being reported!
But here is general problem I am encountering:
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I know that in the example code, the Arduino issued the step command by writing the signal from LOW to HIGH, and varied the speed by how often it did this.
I assumed that the Write-PWM feature would do this same thing, but perhaps my assumption is wrong. I will continue to tinker with this myself, but I would be extremely grateful for any insight you might be able to lend.
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Attached to this is the VI used in this setup, a picture of said VI, as well as a rough sketch of the hardware configuration.
Thank you!
Attachments:
Arduino Stepper Control.vi ‏1224 KB
VI Picture.png ‏82 KB
Configuration Sketch.png ‏522 KB

Hi danjifraga,
I am not so familiar with the Arduino toolkit functions, but you may have better luck looking at the Arduino page at:
www.ni.com/arduino
I'll ask around on Monday to see if anyone is more familiar with the toolkit.
Good luck,
Brian
Brian G.

How to eliminate the noise from the stepper motor

I’m using stepper motors to move a traverse on which a hot-wire anemometer probe is mounted. When the stepper motors are turned on, they induce noise on the analog signal of the hotwire anemometer, or of any other transducer, at multiples of 120Hz.
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An NI 6251 or NI 6024E DAQ card is used with LabVIEW to send digital output signal to the logic controller in order to step the motors.
The AI input channels of either NI 6251 or NI 6024E DAQ cards and LabVIEW are used to acquire the signal of the hot-wire anemometer. Different DAQ cards are used for the data acquisition and the stepper motor control and the noise is transferred through the laptop to the data acquisition card (analog signal).
All cables are shielded and the noise was confirmed to be conductive and not radiative.
There was no difference when measuring the analog signal with Differential or RSE.
As a test, the leads from to the drive’s logic controller were connected to the AI input channels in order to check the magnitude and frequency of the noise flowing to the DAQ card and were found to be 5 V peak-to-peak at 60 Hz.
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It sounds like you have a ground loop issue. If possible, try totally isolating the stepper controller from the data acquistion AI more than you already have. This could include any of the following:
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Use different grounds for the stepper power supply and the DAQ power supply/computer. Isolation transformers can help here.
Use lower inductance lines for the stepper controller. This will reduce the movement of the ground.
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Good luck. Let us know if we can help you more.
This account is no longer active. Contact ShadesOfGray for current posts and information.

STEPPER MOTOR - STEP, Clock, Direction and Preset.

I have wired a stepper motor, driveboard and a amplification circuit to a DAQ card. However the stepper refuses to move. I am willing to pay a small fee to someone who can guide me through the internet. My e-mel is [email protected]

Please check out this thread:
http://forums.ni.com/ni/board/message?board.id=250&message.id=9874
-Alan A.

Write a Labview program to control both speed and direction of stepper motors

Hello,
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Hi Wef,
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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.
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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.

Trouble positioning a stepper motor accurately (to one step)

I'm using a PCI-7344 with an MD7506 motor driver from RS. I'm testing angle sensors whose voltage output is proportional to (you've guessed it...) angle.
I'm stepping the motor round by one step, checking that it's got there by reading the encoder, measuring the sensor voltage and repeating.
My problem is that the motor sometimes 'hunts' around the target position. In closed loop (with an encoder associated with a motor) this results in sometimes not being able to reach the target exactly with the pull-in moves.
Using open-loop and reading the encoder directly I get better results because I can loop more times, but the motor will still 'hunt' around a target point, changing direction a few times as it over
shoots by a step.
As there are a million MAX settings for this I won't list them all here, but I'm checking for a move complete when the InPos flag is set and I have a deadband of 0 steps too. I'm only rotating at 120 step/sec with a 10ms pause between steps.
Do I have to accept that stepper motors are only accurate to +/- 1 step or am I doing something wrong?
Thanks,
Mike
Mike Evans
TRW Conekt
N.I. Alliance Member, UK
http://www.Conekt.net

Mike,
Maybe other people will have better suggestions, but in my case I can advise to either:
1. increase the number of pull-in moves,
2. increase the microstepping of your drive,
2a... together with a higher precision encoder...
Other than that, the accuracy is advertised to +/- 1 step, so maybe you would like to consider a stepper with more steps/rev.
Good luck!, I hope other people will give other suggestions.
Nestor.
Nestor
National Instruments

How to generate digital pulses to run stepper motor in a sinusoidal motion profile using NI DAQ 6229 card

Hi,
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Hi,
   I finally figured out a way to do it. The analog sine wave is converted to digital and sampled. Consecutive values are compared and if the least significant bit(LSB) changes then a pulse is sent to the stepper motor to turn one step.
I have included the sub-VI's that accomplish it for the particular stepper motor and connector block i have. The front panel of both sub-VI's are quite messy but the block diagrams should be much clearer. The sub-VI's get their inputs from a third VI which i have not included. So take a look at the VI connector panel to figure it out. Hope this helps. Kinda messy but worked out fine in the end for my application.
Thanks again for all the help. I appreciate it very much.
Regards,
Prabu Sellappan
Graduate Student
Aerospace and Mechanical Enggineering
University of Southern California
Attachments:
start motor test waveform dtest.vi ‏73 KB
sine profile generation subVI.vi ‏41 KB

Connecting stepper motor to the module 9512

Hello,
I must do project in LabVIEW.
I use the compactRIO with module 9512 (Stepper Drive Interface Module with Encoder Feedback). I built a small program of this tutorial http://www.ni.com/white-paper/9666/en#toc10. Now I need connect stepper motor to the module and I would like to run my VI.
I want to connect small stepper motor (which once was in the 3.5-inch floppy drive - this is bipolar motor with four pins) with module 9512. I don't know which pins DSUB or MDR I must link with my inputs stepper motor. "In Getting started with NI 951x.pdf" written: "Connect the Step and Direction outputs to the stepper drive." and "Connect the Drive Enable output to the stepper drive."
Which outputs I should connect with my stepper motor?
Thank you in advance.

That is correct, these elements or their equivalent. It is necessary to convert the control signals from the 9512 into motor drive signals.
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What is the data throughput in labview. I want to use the parallel as acheap digital i/o to drive a stepper motor.

I am trying to use the parallel port on a win xp machine to send data a@ up to a 3k rate. This is for the the purpose of driving a stepper motor. I have tried the port.out vi and placed this vi in a loop and it on a scope it looks like I am limited to a a 200hz rate. What am I doing wrong??? Can labview do this or is it too slow ???
Thanks

snook wrote:
> what is the data throughput in labview. I want to use the parallel as
> acheap digital i/o to drive a stepper motor.
>
> I am trying to use the parallel port on a win xp machine to send data
> a@ up to a 3k rate. This is for the the purpose of driving a stepper
> motor. I have tried the port.out vi and placed this vi in a loop and
> it on a scope it looks like I am limited to a a 200hz rate. What am I
> doing wrong??? Can labview do this or is it too slow ???
Basically the way the Port I/O VIs are implemented they call through a
device driver for each port access. This slows down the maximum port
accesses to something like 1000 times per second depending on the speed
of your CPU.
There is a way to do it faster but that is a little more trick
y. The
idea is to use a device driver to enable particular port addresses to be
accessed directly from the application level instead of always going
through the kernel.
I have written such a VI library and accompagning DLL and device driver
and made it available on OpenG. It is not yet part of the standard
binary distribution packets so you will have to get it from the CVS
repository.
Go to:
http://cvs.sourceforge.net/viewcvs.py/opengtoolkit/portIO/built/portio/
and download all the files in there including the ones in the
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If you want the nitty gritty technical details you can also look at
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On my 866 MHz Pentium mobile I can increase the number of port accesses
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Rolf Kalbermatter
Rolf Kalbermatter
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a division of Test & Measurement Solutions

I want to run a stepper motor using FPGA card 7851r with 9474 driver C rio 9151 is it possible or can i do in LABVIEW CVI

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Solved!
Go to Solution.

Hi SHV,
actually I don't know in which context you want to use your existing hardware for your stepper motor.
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2. Did you buy the hardware especially for the motor application?
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Here are some basics from NI about motor control
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http://www.ni.com/white-paper/3367/en
NI Motion Control Technical Library
http://www.ni.com/white-paper/3054/en
4. Why do you get the idea the digital output module 9474 is suitable for the stepper motor?
I would recommend to talk directly to the customer support, so we can figure out in detail your aims about
the application. Contact your local NI office or request
a service request on following website:
Service Request Manager
https://sine.ni.com/srm/app/login/p/tab/getassistance
Kind regards,
RupiDo

What are the pin connections from 7764 to stepper motor drive

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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.
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Thanks for getting back to me on this. The controller card that I have is the PCI-7342 controller card. The time of a cycle is about seven minutes. I want to ramp the RPM of the motor from zero up to a max value then return it to zero and then go in the opposite direction . A graph of the RPM vs Time is attached.
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Stepper motor noise in 1 direction

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